The Intelligent Resilient Framework (IRF) technology virtualizes multiple physical devices at the same layer into one virtual fabric to provide data center class availability and scalability. IRF virtualization technology offers processing power, interaction, unified management, and uninterrupted maintenance of multiple devices.

Figure 1 shows an IRF fabric that has two devices, which appear as a single node to the upper-layer and lower-layer devices.

Figure 1 IRF application scenario

IRF provides the following benefits:

· Simplified topology and easy management—An IRF fabric appears as one node and is accessible at a single IP address on the network. You can use this IP address to log in at any member device to manage all the members of the IRF fabric. In addition, you do not need to run the spanning tree feature among the IRF members.

· 1:N redundancy—In an IRF fabric, one member acts as the master to manage and control the entire IRF fabric. All the other members process services while backing up the master. When the master fails, all the other member devices elect a new master from among them to take over without interrupting services.

· IRF link aggregation—You can assign several physical links between neighboring members to their IRF ports to create a load-balanced aggregate IRF connection with redundancy.

· Multichassis link aggregation—You can use the Ethernet link aggregation feature to aggregate the physical links between the IRF fabric and its upstream or downstream devices across the IRF members.

· Network scalability and resiliency—Processing capacity of an IRF fabric equals the total processing capacities of all the members. You can increase ports, network bandwidth, and processing capacity of an IRF fabric simply by adding member devices without changing the network topology.

Network topology

An IRF fabric can use a daisy-chain or ring topology. IRF does not support the full mesh topology. For information about connecting IRF member devices, see "Connecting IRF physical interfaces."

Basic concepts

IRF member roles

IRF uses two member roles: master and standby (called subordinate throughout the documentation).

When devices form an IRF fabric, they elect a master to manage and control the IRF fabric, and all the other devices back up the master. When the master device fails, the other devices automatically elect a new master. For more information about master election, see "Master election."

IRF member ID

An IRF fabric uses member IDs to uniquely identify and manage its members. This member ID information is included as the first part of interface numbers and file paths to uniquely identify interfaces and files in an IRF fabric. For more information about interface and file path naming, see "Interface naming conventions" and "File system naming conventions."

Two devices cannot form an IRF fabric if they use the same member ID. A device cannot join an IRF fabric if its member ID has been used in the fabric.

IRF port

An IRF port is a logical interface that connects IRF member devices. Every IRF-capable device has two IRF ports. The IRF ports are named IRF-port n/1 and IRF-port n/2, where n is the member ID of the switch. The two IRF ports are referred to as IRF-port 1 and IRF-port 2 in this book.

To use an IRF port, you must bind a minimum of one physical interface to it. The physical interfaces assigned to an IRF port automatically form an aggregate IRF link. An IRF port goes down when all its IRF physical interfaces are down.

IRF physical interface

IRF physical interfaces connect IRF member devices and must be bound to an IRF port. They forward traffic between member devices, including IRF protocol packets and data packets that must travel across IRF member devices.

For more information about physical interfaces that can be used for IRF links, see "IRF physical interface requirements."

MAD

An IRF link failure causes an IRF fabric to split in two IRF fabrics operating with the same Layer 3 settings, including the same IP address. To avoid IP address collision and network problems, IRF uses multi-active detection (MAD) mechanisms to detect the presence of multiple identical IRF fabrics, handle collisions, and recover from faults.

IRF domain ID

One IRF fabric forms one IRF domain. IRF uses IRF domain IDs to uniquely identify IRF fabrics and prevent IRF fabrics from interfering with one another.

As shown in Figure 2, IRF fabric 1 contains Device A and Device B, and IRF fabric 2 contains Device C and Device D. Both fabrics use the LACP aggregate links between them for MAD. When a member device receives an extended LACPDU for MAD, it checks the domain ID to see whether the packet is from the local IRF fabric. Then, the device can handle the packet correctly.

Figure 2 A network that contains two IRF domains

IRF split

IRF split occurs when an IRF fabric breaks up into multiple IRF fabrics because of IRF link failures, as shown in Figure 3. The split IRF fabrics operate with the same IP address. IRF split causes routing and forwarding problems on the network. To quickly detect a multi-active collision, configure a minimum of one MAD mechanism (see "Configuring MAD").

Figure 3 IRF split

IRF merge

IRF merge occurs when two split IRF fabrics reunite or when two independent IRF fabrics are united, as shown in Figure 4.

Figure 4 IRF merge

Member priority

Member priority determines the possibility of a member device to be elected the master. A member with higher priority is more likely to be elected the master.

Interface naming conventions

An interface is named in the chassis-id/slot-number/port-index format.

· chassis-id—IRF member ID of the device. This argument defaults to 1. The IRF member ID always takes effect, whether or not the device has formed an IRF fabric with other devices. If the device is alone, the device is regarded a one-chassis IRF fabric.

· slot-number—Slot number of the front panel or expansion interface card.

? The front panel slot number is fixed at 0.

? The slot number of the expansion interface card is 1.

· port-index—Index of the port on the device. Port index depends on the number of ports available on the device. To identify the index of a port, examine its port index mark on the chassis.

For example:

· On the single-chassis IRF fabric Sysname, GigabitEthernet 1/0/1 represents the first fixed port on the device. Set its link type to trunk, as follows:

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] port link-type trunk

· On the multi-chassis IRF fabric Master, GigabitEthernet 3/0/1 represents the first fixed port on member device 3. Set its link type to trunk, as follows:

<Master> system-view

[Master] interface gigabitethernet 3/0/1

[Master-GigabitEthernet3/0/1] port link-type trunk

File system naming conventions

On a single-chassis fabric, you can use its storage device name to access its file system.

On a multichassis IRF fabric, you can use the storage device name to access the file system of the master. To access the file system of any other member device, use the name in the slotmember-ID#storage-device-name format.

For example:

To create and access the test folder under the root directory of the flash memory on the master device:

<Master> mkdir test

Creating directory flash:/test... Done.

<Master> dir

Directory of flash:

0 -rw- 43548660 Jan 01 2011 08:21:29 system.ipe

1 drw- - Jan 01 2011 00:00:30 diagfile

2 -rw- 567 Jan 02 2011 01:41:54 dsakey

3 -rw- 735 Jan 02 2011 01:42:03 hostkey

4 -rw- 36 Jan 01 2011 00:07:52 ifindex.dat

5 -rw- 0 Jan 01 2011 00:53:09 lauth.dat

6 drw- - Jan 01 2011 06:33:55 log

7 drw- - Jan 02 2000 00:00:07 logfile

8 -rw- 23724032 Jan 01 2011 00:49:47 switch-cmw710-system.bin

9 drw- - Jan 01 2000 00:00:07 seclog

10 -rw- 591 Jan 02 2011 01:42:03 serverkey

11 -rw- 4609 Jan 01 2011 00:07:53 startup.cfg

12 -rw- 3626 Jan 01 2011 01:51:56 startup.cfg_bak

13 -rw- 78833 Jan 01 2011 00:07:53 startup.mdb

14 drw- - Jan 01 2011 00:15:48 test

25 drw- - Jan 01 2011 04:16:53 versionInfo

524288 KB total (365292 KB free)

To create and access the test folder under the root directory of the flash memory on member device 3:

<Master> mkdir slot3#flash:/test

Creating directory slot3#flash:/test... Done.

<Master> cd slot3#flash:/test

<Master> pwd

slot3#flash:/test

Or:

<Master> cd slot3#flash:/

<Master> mkdir test

Creating directory slot3#flash:/test... Done.

To copy the file test.ipe on the master to the root directory of the flash memory on member device 3:

# Display the current working path. In this example, the current working path is the root directory of the flash memory on member device 3.

<Master> pwd

slot3#flash:

# Change the current working path to the root directory of the flash memory on the master device.

<Master> cd flash:/

<Master> pwd

flash:

# Copy the file to member device 3.

<Master> copy test.ipe slot3#flash:/

Copy flash:/test.ipe to slot3#flash:/test.ipe?[Y/N]:y

Copying file flash:/test.ipe to slot3#flash:/test.ipe... Done.

For more information about storage device naming conventions, see Fundamentals Configuration Guide.

Configuration synchronization

IRF uses a strict running-configuration synchronization mechanism. In an IRF fabric, all devices obtain and run the running configuration of the master. Configuration changes are automatically propagated from the master to the remaining devices. The configuration files of these devices are retained, but the files do not take effect. The devices use their own startup configuration files only after they are removed from the IRF fabric.

For more information about configuration management, see Fundamentals Configuration Guide.

Suppressing SNMP notifications of packet drops on IRF physical interfaces

Before an IRF member device forwards a packet, it examines its forwarding path in the IRF fabric for a loop. If a loop exists, the device discards the packet on the source interface of the looped path. This loop elimination mechanism will drop a large number of broadcast packets on the IRF physical interfaces.

To suppress SNMP notifications of packet drops that do not require attention, do not monitor packet forwarding on the IRF physical interfaces.

Master election

Master election occurs each time the IRF fabric topology changes in the following situations:

· The IRF fabric is established.

· The master device fails or is removed.

· The IRF fabric splits.

· Independent IRF fabrics merge.

NOTE:

Master election does not occur when two split IRF fabrics merge. All member devices in the Recovery-state IRF fabric automatically reboot to join the active IRF fabric as subordinate members. The master device of the active IRF fabric is the master device of the merged IRF fabric.

Master election selects a master in descending order:

1. Current master, even if a new member has higher priority.

When an IRF fabric is being formed, all members consider themselves as the master. This rule is skipped.

2. Member with higher priority.

3. Member with the longest system uptime.

Two members are considered to start up at the same time if the difference between their startup times is equal to or less than 10 minutes. For these members, the next tiebreaker applies.

4. Member with the lowest CPU MAC address.

For the setup of a new IRF fabric, the subordinate devices must reboot to complete the setup after the master election.

For an IRF merge, devices must reboot if they are in the IRF fabric that fails the master election.

Multi-active handling procedure

The multi-active handling procedure includes detection, collision handling, and failure recovery.

Detection

IRF provides MAD mechanisms by extending LACP, BFD, ARP, and IPv6 ND to detect multi-active collisions. As a best practice, configure a minimum of one MAD mechanism on an IRF fabric. For more information about the MAD mechanisms and their application scenarios, see "MAD mechanisms."

For information about LACP, see Ethernet link aggregation in Layer 2—LAN Switching Configuration Guide. For information about BFD, see High Availability Configuration Guide. For information about ARP, see Layer 3—IP Services Configuration Guide. For information about ND, see IPv6 basics in Layer 3—IP Services Configuration Guide.

Collision handling

When MAD detects a multi-active collision, it sets all IRF fabrics except one to the Recovery state. The fabric that is not placed in Recovery state can continue to forward traffic. The Recovery-state IRF fabrics are inactive and cannot forward traffic.

LACP MAD and BFD MAD use the following process to handle a multi-active collision:

1. Compare the number of members in each fabric.

2. Set all fabrics to the Recovery state except the one that has the most members.

3. Compare the member IDs of the masters if all IRF fabrics have the same number of members.

4. Set all fabrics to the Recovery state except the one that has the lowest numbered master.

5. Shut down all common network interfaces in the Recovery-state fabrics except for the following interfaces:

? Interfaces excluded from being shut down by the system.

? Interfaces specified by using the mad exclude interface command.

In contrast, ARP MAD and ND MAD do not compare the number of members in fabrics. These MAD mechanisms use the following process to handle a multi-active collision:

1. Compare the member IDs of the masters in the IRF fabrics.

2. Set all fabrics to the Recovery state except the one that has the lowest numbered master.

3. Take the same action on the network interfaces in Recovery-state fabrics as LACP MAD and BFD MAD.

Failure recovery

To merge two split IRF fabrics, first repair the failed IRF link and remove the IRF link failure.

· If the IRF fabric in Recovery state fails before the failure is recovered, repair the failed IRF fabric and the failed IRF link.

· If the active IRF fabric fails before the failure is recovered, enable the inactive IRF fabric to take over the active IRF fabric. Then, recover the MAD failure.

MAD mechanisms

As a best practice, configure a minimum of one MAD mechanism on an IRF fabric for prompt IRF split detection.

When you configure multiple MAD mechanisms, follow these restrictions and guidelines:

· Do not configure LACP MAD together with ARP MAD or ND MAD, because they handle collisions differently.

· Do not configure BFD MAD together with ARP MAD or ND MAD. BFD MAD is mutually exclusive with the spanning tree feature. ARP MAD and ND MAD require the spanning tree feature. In addition, BFD MAD handles collisions differently than ARP MAD and ND MAD.

Table 1 compares the MAD mechanisms and their application scenarios.

Table 1 Comparison of MAD mechanisms

MAD mechanism	Advantages	Disadvantages	Application scenario
LACP MAD	· Detection speed is fast. · Runs on existing aggregate links without requiring MAD-dedicated physical links or Layer 3 interfaces.	Requires an intermediate device that supports extended LACP for MAD.	Link aggregation is used between the IRF fabric and its upstream or downstream device.
BFD MAD	· Detection speed is fast. · No intermediate device is required. · Intermediate device, if used, can come from any vendor.	· Requires MAD dedicated physical links and Layer 3 interfaces, which cannot be used for transmitting user traffic. · If no intermediate device is used, any two IRF members must have a BFD MAD link to each other. · If an intermediate device is used, every IRF member must have a BFD MAD link to the intermediate device.	· No special requirements for network scenarios. · If no intermediate device is used, this mechanism is only suitable for IRF fabrics that have a small number of members that are geographically close to one another.
ARP MAD	· No intermediate device is required. · Intermediate device, if used, can come from any vendor. · Does not require MAD dedicated ports.	· Detection speed is slower than BFD MAD and LACP MAD. · The spanning tree feature must be enabled if common Ethernet ports are used for ARP MAD links.	Non-link aggregation IPv4 network scenario. If common Ethernet ports are used, this MAD mechanism is applicable only to the spanning tree-enabled non-link aggregation IPv4 network scenario.
ND MAD	· No intermediate device is required. · Intermediate device, if used, can come from any vendor. · Does not require MAD dedicated ports.	· Detection speed is slower than BFD MAD and LACP MAD. · The spanning tree feature must be enabled.	Spanning tree-enabled non-link aggregation IPv6 network scenario.

LACP MAD

As shown in Figure 5, LACP MAD has the following requirements:

· Every IRF member must have a link with an intermediate device.

· All the links form a dynamic link aggregation group.

· The intermediate device must be a device that supports extended LACP for MAD.

The IRF member devices send extended LACPDUs that convey a domain ID and an active ID (the member ID of the master). The intermediate device transparently forwards the extended LACPDUs received from one member device to all the other member devices.

· If the domain IDs and active IDs sent by all the member devices are the same, the IRF fabric is integrated.

· If the extended LACPDUs convey the same domain ID but different active IDs, a split has occurred. LACP MAD handles this situation as described in "Collision handling."

Figure 5 LACP MAD scenario

BFD MAD

You can configure BFD MAD on VLAN interfaces, Layer 3 aggregate interfaces, or management Ethernet ports.

· If management Ethernet ports are used, BFD MAD must work with an intermediate device. Make sure the following requirements are met:

? Connect a management Ethernet port on each member device to the intermediate device.

? Each member device is assigned a MAD IP address on the master's management Ethernet port. Of all management Ethernet ports on an IRF fabric, only the master's management Ethernet ports are accessible.

· If a VLAN interface is used, BFD MAD can work with or without an intermediate device. Make sure the following requirements are met:

? Each member device has a BFD MAD link to an intermediate device, or all member devices have a BFD MAD link to each other.

? Common Ethernet ports connected by BFD MAD links are assigned to the BFD MAD VLAN.

? Each member device is assigned a MAD IP address on the BFD MAD VLAN interface.

· If a Layer 3 aggregate interface is used, BFD MAD can work with or without an intermediate device. Make sure the following requirements are met:

? Each member device has a BFD MAD link to an intermediate device, or all member devices have a BFD MAD link to each other.

? Common Ethernet ports connected by BFD MAD links are assigned to the aggregation group of the Layer 3 aggregate interface. The aggregation group operates in static link aggregation mode.

? Each member device is assigned a MAD IP address on the Layer 3 aggregate interface.

IMPORTANT:

· The MAD IP addresses identify the member devices and must belong to the same subnet.

· The BFD MAD links must be dedicated. Do not use BFD MAD links for any other purposes.

Figure 6 shows a typical BFD MAD scenario that uses an intermediate device. On the intermediate device, assign the ports on the BFD MAD links to the same VLAN.

Figure 7 shows a typical BFD MAD scenario that does not use an intermediate device. As a best practice, use an intermediate device to connect IRF member devices if the IRF fabric has more than two member devices. A full mesh of IRF members might cause broadcast loops.

With BFD MAD, the master attempts to establish BFD sessions with other member devices by using its MAD IP address as the source IP address.

· If the IRF fabric is integrated, only the MAD IP address of the master takes effect. The master cannot establish a BFD session with any other member. If you execute the display bfd session command, the state of the BFD sessions is Down.

· When the IRF fabric splits, the IP addresses of the masters in the split IRF fabrics take effect. The masters can establish a BFD session. If you execute the display bfd session command, the state of the BFD session between the two devices is Up.

Figure 6 BFD MAD scenario with an intermediate device

Figure 7 BFD MAD scenario without an intermediate device

ARP MAD

ARP MAD detects multi-active collisions by using extended ARP packets that convey the IRF domain ID and the active ID (the member ID of the master).

You can use common or management Ethernet ports for ARP MAD.

· If management Ethernet ports are used, ARP MAD must work with an intermediate device. Make sure the following requirements are met:

? Connect a management Ethernet port on each member device to the intermediate device.

? On the intermediate device, you must assign the ports used for ARP MAD to the same VLAN.

· If common Ethernet ports are used, ARP MAD can work with or without an intermediate device. Make sure the following requirements are met:

? If an intermediate device is used, connect each IRF member device to the intermediate device. Run the spanning tree feature between the IRF fabric and the intermediate device. In this situation, data links can be used.

? If an intermediate device is not used, connect each IRF member device to all other member devices. In this situation, IRF links cannot be used for ARP MAD.

Figure 8 shows a typical ARP MAD scenario that uses an intermediate device.

Each IRF member compares the domain ID and the active ID in incoming extended ARP packets with its domain ID and active ID.

· If the domain IDs are different, the extended ARP packet is from a different IRF fabric. The device does not continue to process the packet with the MAD mechanism.

· If the domain IDs are the same, the device compares the active IDs.

? If the active IDs are different, the IRF fabric has split.

? If the active IDs are the same, the IRF fabric is integrated.

Figure 8 ARP MAD scenario

ND MAD

ND MAD detects multi-active collisions by using NS packets to transmit the IRF domain ID and the active ID (the member ID of the master).

You can set up ND MAD links between neighbor IRF member devices or between each IRF member device and an intermediate device (see Figure 9). If an intermediate device is used, you must also run the spanning tree protocol between the IRF fabric and the intermediate device.

Each IRF member device compares the domain ID and the active ID in incoming NS packets with its domain ID and active ID.

· If the domain IDs are different, the NS packet is from a different IRF fabric. The device does not continue to process the packet with the MAD mechanism.

· If the domain IDs are the same, the device compares the active IDs.

? If the active IDs are different, the IRF fabric has split.

? If the active IDs are the same, the IRF fabric is integrated.

Figure 9 ND MAD scenario

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Hardware compatibility

An S5130-HI switch can form an IRF fabric only with devices in the same series.

General restrictions and configuration guidelines

For a successful IRF setup, follow the restrictions and guidelines in this section and the setup procedure in "Setup and configuration task list."

Software requirements

All IRF member devices must run the same software image version. Make sure the software auto-update feature is enabled on all member devices.

IRF physical interface requirements

Candidate IRF physical interfaces

Use ports in the following table for IRF links:

Device model	Candidate IRF physical interfaces
S5130-30S-HI S5130-54S-HI	· SFP+ ports on the front panel. · QSFP+ ports on the rear panel.
S5130-30F-HI S5130-30C-HI S5130-30C-PWR-HI S5130-34C-HI S5130-54C-HI S5130-54C-PWR-HI	· SFP+ ports on the front panel. · 10GBase-T Ethernet ports, SFP+ ports, and QSFP+ ports on the expansion interface cards of the rear panel.
S5130-54QS-HI	SFP+ ports and QSFP+ ports on the front panel.

IRF port binding restrictions

When you bind IRF physical interfaces to an IRF port, follow these restrictions and guidelines:

· The 10GBase-T Ethernet ports and SFP+ ports must operate at 10 Gbps, and the QSFP+ ports must operate at 20 Gbps (the maximum rate).

· On the S5130-54QS-HI switch, the two QSFP+ ports cannot be assigned to the same IRF port. The SFP+ ports numbered 49 and 50 can be assigned to the same IRF port, and the SFP+ ports numbered 51 and 52 can be assigned to the same IRF port.

· On other S5130-HI switches, IRF physical interfaces can be assigned to the same IRF port if they operate at the same rate.

Selecting transceiver modules and cables

When you select transceiver modules and cables, follow these restrictions and guidelines:

· Use Category 6A (or above) twisted-pair cables to connect 10GBase-T Ethernet ports in a short distance.

· Use SFP+ transceiver modules and fibers to connect SFP+ ports for a long-distance connection.

· Use SFP+ or QSFP+ DAC cables to connect SFP+ or QSFP+ ports for a short-distance connection.

· The transceiver modules at the two ends of an IRF link must be the same type.

For more information about the transceiver modules and DAC cables, see the switch installation guide and H3C Transceiver Modules User Guide.

NOTE:

The transceiver modules and DAC cables available for the switch are subject to change over time. For the most up-to-date list of transceiver modules and DAC cables, contact your H3C sales representative.

Connecting IRF ports

When you connect two neighboring IRF members, connect the physical interfaces of IRF-port 1 on one member to the physical interfaces of IRF-port 2 on the other.

Feature compatibility

Make sure the feature settings in Table 2 are the same across member devices.

Table 2 IRF and feature compatibility

Feature	Command	Remarks
Enhanced ECMP mode	ecmp mode enhanced	See Layer 3—IP Routing Configuration Guide.
Maximum number of ECMP routes	max-ecmp-num	See Layer 3—IP Routing Configuration Guide.

Configuration backup

As a best practice, back up the next-startup configuration file on a device before adding the device to an IRF fabric as a subordinate.

A subordinate device's next-startup configuration file might be overwritten if the master and the subordinate use the same file name for their next-startup configuration files. You can use the backup file to restore the original configuration after removing the subordinate from the IRF fabric.

Setup and configuration task list

To set up and configure an IRF fabric:

Tasks at a glance	Remarks
1. (Required.) Planning the IRF fabric setup	N/A
2. (Required.) Assigning a member ID to each IRF member device	Perform this task on each member device.
3. (Optional.) Specifying a priority for each member device	Perform this task on one or multiple member devices to affect the master election result.
4. (Required.) Connecting IRF physical interfaces	N/A
5. (Required.) Binding physical interfaces to IRF ports	Perform this task on each member device. When you complete IRF port binding and activation on all IRF member devices, the IRF fabric is formed.
6. (Required.) Accessing the IRF fabric	When you log in to the IRF fabric, you are placed at the master's CLI, where you complete subsequent IRF settings and configure other features for the member devices as if they were one device.
7. (Optional.) Bulk-configuring basic IRF settings for a member device	Perform this task to bulk-configure the member ID, domain ID, priority, and IRF port bindings for a device.
8. (Optional.) Configuring a member device description	N/A
9. (Optional.) Configuring IRF link load sharing mode: ? Configuring the global load sharing mode ? Configuring a port-specific load sharing mode	N/A
10. (Optional.) Configuring IRF bridge MAC persistence	N/A
11. (Optional.) Enabling software auto-update for software image synchronization	As a best practice, enable software auto-update to ensure system software image synchronization.
12. (Optional.) Setting the IRF link down report delay	N/A
13. (Required.) Configuring MAD: ? Configuring LACP MAD ? Configuring BFD MAD ? Configuring ARP MAD ? Configuring ND MAD ? Excluding an interface from the shutdown action upon detection of multi-active collision	MAD mechanisms are independent of one another. You can configure multiple MAD mechanisms for an IRF fabric.
14. (Optional.) Recovering an IRF fabric	N/A
15. (Optional.) Removing an expansion interface card that has IRF physical interfaces	N/A
16. (Optional.) Replacing an expansion interface card that has IRF physical interfaces	N/A

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Planning the IRF fabric setup

Consider the following items when you plan an IRF fabric:

· Hardware compatibility and restrictions.

· IRF fabric size.

· Master device.

· IRF physical interfaces.

· Member ID and priority assignment scheme.

· Fabric topology and cabling scheme.

For more information about hardware and cabling, see the device installation guide.

Assigning a member ID to each IRF member device

CAUTION:

In an IRF fabric, changing IRF member IDs might cause undesirable configuration changes and data loss. Before you do that, back up the configuration, and make sure you fully understand the impact on your network. For example, all member switches in an IRF fabric are the same model. If you swapped the IDs of any two members, their interface settings would also be swapped.

To create an IRF fabric, you must assign a unique IRF member ID to each member device.

To prevent any undesirable configuration change or data loss, avoid changing member IDs after the IRF fabric is formed.

The new member ID takes effect at a reboot. After the device reboots, the settings on all member ID-related physical resources (including common physical network interfaces) are removed, regardless of whether you have saved the configuration.

To assign a member ID to a device:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Assign a member ID to a member device.	irf member member-id renumber new-member-id	The default IRF member ID is 1.
3. (Optional.) Save the configuration.	save	If you have bound physical interfaces to IRF ports or assigned member priority, you must perform this step for these settings to take effect after the reboot.
4. Reboot the device.	reboot [ slot slot-number ] [ force ]	N/A

Specifying a priority for each member device

IRF member priority represents the possibility for a device to be elected the master in an IRF fabric. A larger priority value indicates a higher priority.

A change to member priority affects the election result at the next master election, but it does not cause an immediate master re-election.

To specify a priority for a member device:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Specify a priority for the device.	irf member member-id priority priority	The default IRF member priority is 1.

Connecting IRF physical interfaces

When you connect two neighboring IRF members, connect the physical interfaces of IRF-port 1 on one member to the physical interfaces of IRF-port 2 on the other (see Figure 10).

For example, you have four chassis: A, B, C, and D. IRF-port 1 and IRF-port 2 are represented by A1 and A2 on chassis A, represented by B1 and B2 on chassis B, and so on. To connect the four chassis into a ring topology of A-B-C-D(A), the IRF link cabling scheme must be one of the following:

· A1-B2, B1-C2, C1-D2, and D1-A2.

· A2-B1, B2-C1, C2-D1, and D2-A1.

IMPORTANT:

No intermediate devices are allowed between neighboring members.

Figure 10 Connecting IRF physical interfaces

Connect the devices into a daisy-chain topology or a ring topology. A ring topology is more reliable (see Figure 11). In ring topology, the failure of one IRF link does not cause the IRF fabric to split as in daisy-chain topology. Rather, the IRF fabric changes to a daisy-chain topology without interrupting network services.

Figure 11 Daisy-chain topology vs. ring topology

Binding physical interfaces to IRF ports

Configuration restrictions and guidelines

When you bind physical interfaces to IRF ports, follow the restrictions in "IRF physical interface requirements."

On a physical interface bound to an IRF port, you can execute only commands in the following table:

Category	Commands	Remarks
Interface commands	Including: · description · flow-interval · priority-flow-control · priority-flow-control no-drop dot1p · shutdown	See Layer 2—LAN Switching Command Reference.
LLDP commands	Including: · lldp admin-status · lldp check-change-interval · lldp enable · lldp encapsulation snap · lldp notification remote-change enable · lldp tlv-enable	See Layer 2—LAN Switching Command Reference.

Configuration procedure

To bind physical interfaces to IRF ports:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter interface view or interface range view.	· Enter interface range view: ? Method 1: interface range { interface-type interface-number [ to interface-type interface-number ] } &<1-24> ? Method 2: interface range name name [ interface { interface-type interface-number [ to interface-type interface-number ] } &<1-24> ] · Enter interface view: interface interface-type interface-number	To shut down a range of IRF physical interfaces, enter interface range view. To shut down one IRF physical interface, enter its interface view.
3. Shut down the physical interfaces.	shutdown	By default, all physical interfaces are up.
4. Return to system view.	quit	N/A
5. Enter IRF port view.	irf-port member-id/irf-port-number	N/A
6. Bind each physical interface to the IRF port.	port group interface interface-type interface-number	By default, no physical interfaces are bound to an IRF port. Repeat this step to assign multiple physical interfaces to the IRF port. You can bind a maximum of four physical interfaces to an IRF port.
7. Return to system view.	quit	N/A
8. Enter interface view or interface range view.	· Enter interface range view: ? Method 1: interface range { interface-type interface-number [ to interface-type interface-number ] } &<1-24> ? Method 2: interface range name name [ interface { interface-type interface-number [ to interface-type interface-number ] } &<1-24> ] · Enter interface view: interface interface-type interface-number	N/A
9. Bring up the physical interfaces.	undo shutdown	N/A
10. Return to system view.	quit	N/A
11. Save the configuration.	save	Activating IRF port configurations causes IRF merge and reboot. To avoid data loss, save the running configuration to the startup configuration file before you perform the operation.
12. Activate the IRF port settings.	irf-port-configuration active	After this step is performed, the state of the IRF port changes to UP, the member devices elect a master automatically, and the subordinate device reboots automatically. After the IRF fabric is formed, you can add additional physical interfaces to an IRF port (in UP state) without repeating this step.

Accessing the IRF fabric

The IRF fabric appears as one device after it is formed. You configure and manage all IRF members at the CLI of the master. All settings you have made are propagated to the IRF members automatically.

The following methods are available for accessing an IRF fabric:

· Local login—Log in through the console port of any member device.

· Remote login—Log in at a Layer 3 interface on any member device by using methods including Telnet and SNMP.

When you log in to an IRF fabric, you are placed at the CLI of the master, regardless of at which member device you are logged in.

For more information, see login configuration in Fundamentals Configuration Guide.

Bulk-configuring basic IRF settings for a member device

IMPORTANT:

The member device reboots immediately after you specify a new member ID for it. Make sure you are aware of the impact on the network.

Use the easy IRF feature to bulk-configure basic IRF settings for a member device, including the member ID, domain ID, priority, and IRF port bindings.

The easy IRF feature provides the following configuration methods:

· Interactive method—Enter the easy-irf command without parameters. The system will guide you to set the parameters step by step.

· Non-interactive method—Enter the easy-irf command with parameters.

As a best practice, use the interactive method if you are new to IRF.

When you specify IRF physical interfaces for an IRF port, you must follow the IRF port binding restrictions in "IRF physical interface requirements."

If you specify IRF physical interfaces by using the interactive method, you must also follow these restrictions and guidelines:

· Do not enter spaces between the interface type and interface number.

· Use a comma (,) to separate two physical interfaces. No spaces are allowed between interfaces.

To bulk-configure basic IRF settings for a device:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Bulk-configure basic IRF settings for the device.	easy-irf [ member member-id [ renumber new-member-id ] domain domain-id [ priority priority ] [ irf-port1 interface-list1 ] [ irf-port2 interface-list2 ] ]	Make sure the new member ID is unique in the IRF fabric to which the device will be added. If you execute this command multiple times, the following settings take effect: · The most recent settings for the member ID, domain ID, and priority. · IRF port bindings added through executions of the command. You can bind a maximum of four physical interfaces to an IRF port. To remove an IRF physical interface from an IRF port, you must use the undo port group interface command in IRF port view.

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Bulk-configure basic IRF settings for the device.

easy-irf [ member member-id [ renumber new-member-id ] domain domain-id [ priority priority ] [ irf-port1 interface-list1 ] [ irf-port2 interface-list2 ] ]

Make sure the new member ID is unique in the IRF fabric to which the device will be added.

If you execute this command multiple times, the following settings take effect:

· The most recent settings for the member ID, domain ID, and priority.

· IRF port bindings added through executions of the command.

You can bind a maximum of four physical interfaces to an IRF port.

To remove an IRF physical interface from an IRF port, you must use the undo port group interface command in IRF port view.

Configuring a member device description

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Configure a description for a member device.	irf member member-id description text	By default, no member device description is configured.

Configuring IRF link load sharing mode

On an IRF port, traffic is balanced across its physical links.

You can configure the IRF port to distribute traffic based on any combination of the following criteria:

· Source IP addresses.

· Destination IP addresses.

· Source MAC addresses.

· Destination MAC addresses.

The criteria can also be packet types, such as Layer 2, IPv4, and IPv6. If the device does not support a criterion combination, the system displays an error message.

Configure the IRF link load sharing mode for IRF links in system view or IRF port view:

· In system view, the configuration is global and takes effect on all IRF ports.

· In IRF port view, the configuration is port specific and takes effect only on the specified IRF port.

An IRF port preferentially uses the port-specific load sharing mode. If no port-specific load sharing mode is available, the IRF port uses the global load sharing mode.

The IRF link load sharing mode takes effect on all types of packets, including unicast, multicast, and broadcast.

Configuring the global load sharing mode

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Configure the global IRF link load sharing mode.	irf-port global load-sharing mode { destination-ip \| destination-mac \| source-ip \| source-mac } *	By default, packets are distributed based on the load sharing mode automatically selected depending on the packet type. If you execute this command multiple times, the most recent configuration takes effect.

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Configure the global IRF link load sharing mode.

irf-port global load-sharing mode { destination-ip | destination-mac | source-ip | source-mac } *

By default, packets are distributed based on the load sharing mode automatically selected depending on the packet type.

If you execute this command multiple times, the most recent configuration takes effect.

Configuring a port-specific load sharing mode

Before you configure a port-specific load sharing mode, make sure you have bound a minimum of one physical interface to the IRF port.

To configure a port-specific load sharing mode for an IRF port:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter IRF port view.	irf-port member-id/irf-port-number	N/A
3. Configure the port-specific load sharing mode.	irf-port load-sharing mode { destination-ip \| destination-mac \| source-ip \| source-mac } *	By default, the global IRF link load sharing mode is used. If you execute this command multiple times, the most recent configuration takes effect.

Configuring IRF bridge MAC persistence

By default, an IRF fabric uses the bridge MAC address of the master device as its bridge MAC address. Layer 2 protocols, such as LACP, use this bridge MAC address to identify the IRF fabric. On a switched LAN, the bridge MAC address must be unique.

To avoid duplicate bridge MAC addresses, an IRF fabric can change its bridge MAC address automatically after the address owner leaves. However, the change causes temporary traffic disruption.

Depending on the network condition, enable the IRF fabric to retain or change its bridge MAC address after the address owner leaves. Available options include:

· irf mac-address persistent timer—Bridge MAC address of the IRF fabric is retained for 6 minutes after the address owner leaves. If the address owner does not return before the timer expires, the IRF fabric uses the bridge MAC address of the current master as its bridge MAC address. This option avoids unnecessary bridge MAC address changes caused by device reboot, transient link failure, or purposeful link disconnection.

· irf mac-address persistent always—Bridge MAC address of the IRF fabric does not change after the address owner leaves.

· undo irf mac-address persistent—Bridge MAC address of the current master replaces the original IRF bridge MAC address as soon as the owner of the original address leaves.

When IRF fabrics merge, IRF ignores the IRF bridge MAC address and checks the bridge MAC address of each member device in the IRF fabrics. IRF merge fails if any two member devices have the same bridge MAC address.

When you configure IRF bridge MAC persistence, follow these restrictions and guidelines:

· If ARP MAD or ND MAD is used with the spanning tree feature, disable IRF bridge MAC persistence by using the undo irf mac-address persistent command.

· If the IRF fabric uses a daisy-chain topology and has aggregate links with upstream or downstream devices, make sure IRF bridge MAC persistence is not disabled. The setting prevents transmission delay or packet loss after the address owner leaves or reboots.

· If the IRF fabric has cross-member aggregate links, do not use the undo irf mac-address persistent command to avoid unnecessary traffic disruption.

To configure the IRF bridge MAC persistence setting:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Configure IRF bridge MAC persistence.	· Retain the bridge MAC address even if the address owner has left the fabric: irf mac-address persistent always · Retain the bridge MAC address for 6 minutes after the address owner leaves the fabric: irf mac-address persistent timer · Change the bridge MAC address as soon as the address owner leaves the fabric: undo irf mac-address persistent	By default, the IRF bridge MAC address remains unchanged for 6 minutes after the address owner leaves the fabric.

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Configure IRF bridge MAC persistence.

· Retain the bridge MAC address even if the address owner has left the fabric:
irf mac-address persistent always

· Retain the bridge MAC address for 6 minutes after the address owner leaves the fabric:
irf mac-address persistent timer

· Change the bridge MAC address as soon as the address owner leaves the fabric:
undo irf mac-address persistent

By default, the IRF bridge MAC address remains unchanged for 6 minutes after the address owner leaves the fabric.

Enabling software auto-update for software image synchronization

IMPORTANT:

To ensure a successful software auto-update in a multi-user environment, prevent anyone from rebooting member devices during the auto-update process. To inform administrators of the auto-update status, configure the information center to output the status messages to configuration terminals (see Network Management and Monitoring Configuration Guide).

The software auto-update feature automatically synchronizes the current software images of the master to devices that are attempting to join the IRF fabric.

To join an IRF fabric, a device must use the same software images as the master in the fabric.

When you add a device to the IRF fabric, software auto-update compares the startup software images of the device with the current software images of the IRF master. If the two sets of images are different, the device automatically performs the following operations:

1. Downloads the current software images of the master.

2. Sets the downloaded images as its main startup software images.

3. Reboots with the new software images to rejoin the IRF fabric.

You must manually update the new device with the software images running on the IRF fabric if software auto-update is disabled.

Configuration prerequisites

Make sure the device you are adding to the IRF fabric has sufficient storage space for the new software images.

If sufficient storage space is not available, the device automatically deletes the current software images. If the reclaimed space is still insufficient, the device cannot complete the auto-update. You must reboot the device, and then access the BootWare menus to delete files.

Configuration procedure

To enable automatic software synchronization with the master:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enable software auto-update.	irf auto-update enable	By default, software auto-update is enabled.

Setting the IRF link down report delay

To prevent frequent IRF splits and merges during link flapping, configure the IRF ports to delay reporting link down events.

An IRF port does not report a link down event to the IRF fabric immediately after its link changes from up to down. If the IRF link state is still down when the delay is reached, the port reports the change to the IRF fabric.

An IRF port does not delay a link up event. It reports the link up event immediately after the IRF link comes up. However, for fiber IRF physical interfaces, the IRF port does not report the link up event immediately to the IRF fabric if the link up event occurs in the following conditions:

1. The IRF link was down because the physical interfaces were shut down by using the shutdown command or were disconnected.

2. The IRF link is recovered after you execute the undo shutdown command or reconnect the IRF physical interfaces.

In the above conditions, the IRF port reports the link up event to the IRF fabric after the delay time expires.

When you configure the IRF link down report delay, follow these restrictions and guidelines:

· Make sure the IRF link down report delay is shorter than the heartbeat or hello timeout settings of upper-layer protocols (for example, CFD, VRRP, and OSPF). If the report delay is longer than the timeout setting of a protocol, unnecessary recalculations might occur.

· Set the delay to 0 seconds in the following situations:

? The IRF fabric requires a fast master/subordinate or IRF link switchover.

? The BFD or GR feature is used.

? You want to shut down an IRF physical interface or reboot an IRF member device. (After you complete the operation, reconfigure the delay depending on the network condition.)

To set the IRF link down report delay:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the IRF link down report delay.	irf link-delay interval	The default IRF link down report delay is 4 seconds.

Configuring MAD

When you configure MAD, follow these restrictions and guidelines:

· As a best practice, configure a minimum of one MAD mechanism on an IRF fabric for prompt IRF split detection.

· When you configure multiple MAD mechanisms, follow these restrictions and guidelines:

? Do not configure LACP MAD together with ARP MAD or ND MAD, because they handle collisions differently.

? Do not configure BFD MAD together with ARP MAD or ND MAD. BFD MAD is mutually exclusive with the spanning tree feature. ARP MAD and ND MAD require the spanning tree feature. In addition, BFD MAD handles collisions differently than ARP MAD and ND MAD.

· If LACP MAD, ARP MAD, or ND MAD runs between two IRF fabrics, assign each fabric a unique IRF domain ID. (For BFD MAD, this task is optional.)

· An IRF fabric has only one IRF domain ID. You can change the IRF domain ID by using the following commands: irf domain, mad enable, mad arp enable, or mad nd enable. The IRF domain IDs configured by using these commands overwrite each other.

· To prevent an interface from being shut down when the IRF fabric transits to the Recovery state, use the mad exclude interface command.

· To bring up the interfaces shut down by a MAD mechanism in a Recovery-state IRF fabric, use the mad restore command instead of the undo shutdown command. The mad restore command activates the Recovery-state IRF fabric.

Configuring LACP MAD

When you use LACP MAD, follow these guidelines:

· The intermediate device must be a device that supports extended LACP for MAD.

· If the intermediate device is also an IRF fabric, assign the two IRF fabrics different domain IDs for correct split detection.

· Use dynamic link aggregation mode. MAD is LACP dependent. Even though LACP MAD can be configured on both static and dynamic aggregate interfaces, it takes effect only on dynamic aggregate interfaces.

· Configure link aggregation settings on the intermediate device.

To configure LACP MAD:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Assign a domain ID to the IRF fabric.	irf domain domain-id	The default IRF domain ID is 0.
3. Create an aggregate interface and enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface view: interface route-aggregation interface-number	Perform this step also on the intermediate device.
4. Configure the aggregation group to operate in dynamic aggregation mode.	link-aggregation mode dynamic	By default, an aggregation group operates in static aggregation mode. Perform this step also on the intermediate device.
5. Enable LACP MAD.	mad enable	By default, LACP MAD is disabled.
6. Return to system view.	quit	N/A
7. Enter Ethernet interface view or interface range view.	· Enter interface range view: ? Method 1: interface range { interface-type interface-number [ to interface-type interface-number ] } &<1-24> ? Method 2: interface range name name [ interface { interface-type interface-number [ to interface-type interface-number ] } &<1-24> ] · Enter Ethernet interface view: interface interface-type interface-number	To assign a range of ports to the aggregation group, enter interface range view. To assign one port to the aggregation group, enter Ethernet interface view.
8. Assign the Ethernet port or the range of Ethernet ports to the specified aggregation group.	port link-aggregation group group-id	Multichassis link aggregation is allowed. Also perform this step on the intermediate device.

Configuring BFD MAD

Before you configure BFD MAD, choose a BFD MAD link scheme as described in "BFD MAD."

As a best practice, connect the BFD MAD links after you finish the BFD MAD configuration.

Configuring BFD MAD that uses a VLAN interface

When you configure BFD MAD on a VLAN interface, follow these restrictions and guidelines:

Category	Restrictions and guidelines
BFD MAD VLAN	· Do not enable BFD MAD on VLAN-interface 1. · If you are using an intermediate device, perform the following tasks: ? On the IRF fabric and the intermediate device, create a VLAN for BFD MAD. ? On the IRF fabric and the intermediate device, assign the ports of BFD MAD links to the BFD MAD VLAN. ? On the IRF fabric, create a VLAN interface for the BFD MAD VLAN. · Make sure the IRF fabrics on the network use different BFD MAD VLANs. · Make sure the BFD MAD VLAN contains only ports on the BFD MAD links. Exclude a port from the BFD MAD VLAN if that port is not on a BFD MAD link. If you have assigned that port to all VLANs by using the port trunk permit vlan all command, use the undo port trunk permit command to exclude that port from the BFD MAD VLAN.
BFD MAD VLAN and feature compatibility	Do not use the BFD MAD VLAN for any purpose other than configuring BFD MAD. · Use only the mad bfd enable and mad ip address commands on the VLAN interface used for BFD MAD. If you configure other features, both BFD MAD and other features on the interface might run incorrectly. · Disable the spanning tree feature on all Layer 2 Ethernet ports in the BFD MAD VLAN. The MAD feature is mutually exclusive with the spanning tree feature.
MAD IP address	· Use the mad ip address command instead of the ip address command to configure MAD IP addresses on the BFD MAD-enabled VLAN interface. · Make sure all the MAD IP addresses are on the same subnet.

To configure BFD MAD on a VLAN interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. (Optional.) Assign a domain ID to the IRF fabric.	irf domain domain-id	By default, the domain ID of an IRF fabric is 0.
3. Create a VLAN dedicated to BFD MAD.	vlan vlan-id	By default, only VLAN 1 exists.
4. Return to system view.	quit	N/A
5. Enter interface view or interface range view.	· Enter interface range view: interface range { interface-type interface-number [ to interface-type interface-number ] } &<1-24> · Enter interface view: interface interface-type interface-number	To assign a range of ports to the BFD MAD VLAN, enter interface range view. To assign one port to the BFD MAD VLAN, enter Ethernet interface view.
6. Assign the port or the range of ports to the BFD MAD VLAN.	· Assign the port to the VLAN as an access port: port access vlan vlan-id · Assign the port to the VLAN as a trunk port: port trunk permit vlan vlan-id · Assign the port to the VLAN as a hybrid port: port hybrid vlan vlan-id { tagged \| untagged }	The link type of BFD MAD ports can be access, trunk, or hybrid. The default link type of a port is access.
7. Return to system view.	quit	N/A
8. Create the VLAN interface and enter VLAN interface view.	interface vlan-interface vlan-interface-id	N/A
9. Enable BFD MAD.	mad bfd enable	By default, BFD MAD is disabled.
10. Assign a MAD IP address to a member device on the VLAN interface.	mad ip address ip-address { mask \| mask-length } member member-id	By default, no MAD IP addresses are configured on any VLAN interfaces. Repeat this step to assign a MAD IP address to each member device on the VLAN interface.

Configuring BFD MAD that uses a Layer 3 aggregate interface

When you configure BFD MAD on a Layer 3 aggregate interface, follow these restrictions and guidelines:

Category	Restrictions and guidelines
BFD MAD-enabled Layer 3 aggregate interface	Make sure the Layer 3 aggregate interface operates in static aggregation mode.
BFD MAD VLAN	· On the intermediate device (if any), assign the ports on the BFD MAD links to the same VLAN. Do not assign the ports to an aggregate interface. If the ports are hybrid ports, make sure these ports are untagged members of their PVIDs. · If the intermediate device acts as a BFD MAD intermediate device for multiple IRF fabrics, assign different BFD MAD VLANs to the IRF fabrics. · Do not use the BFD MAD VLAN on the intermediate device for any purposes other than BFD MAD. · Make sure the BFD MAD VLAN on the intermediate device contains only ports on the BFD MAD links. Exclude a port from the BFD MAD VLAN if that port is not on a BFD MAD link. If you have assigned that port to all VLANs by using the port trunk permit vlan all command, use the undo port trunk permit command to exclude that port from the BFD MAD VLAN.
BFD MAD-enabled Layer 3 aggregate interface and feature compatibility	Use only the mad bfd enable and mad ip address commands on the BFD MAD-enabled interface. If you configure other features, both BFD MAD and other features on the interface might run incorrectly.
MAD IP address	· To avoid network issues, only use the mad ip address command to configure IP addresses on the BFD MAD-enabled interface. Do not configure an IP address by using the ip address command or configure a VRRP virtual address on the BFD MAD-enabled interface. · Make sure all the MAD IP addresses are on the same subnet.

To configure BFD MAD on a Layer 3 aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. (Optional.) Assign a domain ID to the IRF fabric.	irf domain domain-id	By default, the domain ID of an IRF fabric is 0.
3. Create a Layer 3 aggregate interface for BFD MAD.	interface route-aggregation interface-number	N/A
4. Return to system view.	quit	N/A
5. Enter interface view or interface range view.	· Enter interface range view: ? Method 1: interface range { interface-type interface-number [ to interface-type interface-number ] } &<1-24> ? Method 2: interface range name name [ interface { interface-type interface-number [ to interface-type interface-number ] } &<1-24> ] · Enter interface view: interface interface-type interface-number	To assign a range of ports to the aggregation group for the aggregate interface, enter interface range view. To assign one port to the aggregation group for the aggregate interface, enter Ethernet interface view.
6. Assign the port or the range of ports to the aggregation group for the aggregate interface.	port link-aggregation group group-id	Make sure the group number is identical to the aggregate interface number.
7. Return to system view.	quit	N/A
8. Enter Layer 3 aggregate interface view.	interface route-aggregation interface-number	N/A
9. Enable BFD MAD.	mad bfd enable	By default, BFD MAD is disabled.
10. Assign a MAD IP address to a member device on the Layer 3 aggregate interface.	mad ip address ip-address { mask \| mask-length } member member-id	By default, no MAD IP addresses are configured on aggregate interfaces. Repeat this step to assign a MAD IP address to each member device on the aggregate interface.

Configuring BFD MAD that uses management Ethernet ports

When you configure BFD MAD that uses management Ethernet ports, follow these restrictions and guidelines:

Category	Restrictions and guidelines
Management Ethernet ports for BFD MAD	Connect a management Ethernet port on each member device to the common Ethernet ports on the intermediate device.
BFD MAD VLAN	· On the intermediate device, create a VLAN for BFD MAD, and assign the ports used for BFD MAD to the VLAN. On the IRF fabric, you do not need to assign the management Ethernet ports to the VLAN. · Make sure the IRF fabrics on the network use different BFD MAD VLANs. · Make sure the BFD MAD VLAN on the intermediate device contains only ports on the BFD MAD links.
MAD IP address	· Use the mad ip address command instead of the ip address command to configure MAD IP addresses on the BFD MAD-enabled management Ethernet ports. · Make sure all the MAD IP addresses are on the same subnet.

To configure BFD MAD that uses management Ethernet ports:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. (Optional.) Assign a domain ID to the IRF fabric.	irf domain domain-id	By default, the domain ID of an IRF fabric is 0.
3. Enter management Ethernet interface view.	interface M-GigabitEthernet interface-number	Of all management Ethernet ports on an IRF fabric, only the master's management Ethernet ports are accessible.
4. Enable BFD MAD.	mad bfd enable	By default, BFD MAD is disabled.
5. Assign a MAD IP address to each member device.	mad ip address ip-address { mask \| mask-length } member member-id	By default, no MAD IP addresses are configured.

Configuring ARP MAD

Before you configure ARP MAD, choose an ARP MAD link scheme as described in "ARP MAD."

As a best practice, connect the ARP MAD links after you finish the ARP MAD configuration if you are not using existing data links as ARP MAD links.

Configuring ARP MAD that uses common Ethernet ports

Configure ARP MAD on a VLAN interface if you use common Ethernet ports for ARP MAD.

When you configure ARP MAD that uses common Ethernet ports, follow these restrictions and guidelines:

Category	Restrictions and guidelines
ARP MAD VLAN	· Do not enable ARP MAD on VLAN-interface 1. · If you are using an intermediate device, perform the following tasks: ? On the IRF fabric and the intermediate device, create a VLAN for ARP MAD. ? On the IRF fabric and the intermediate device, assign the ports of ARP MAD links to the ARP MAD VLAN. ? On the IRF fabric, create a VLAN interface for the ARP MAD VLAN. · Do not use the ARP MAD VLAN for any other purposes.
ARP MAD and feature configuration	If an intermediate device is used, make sure the following requirements are met: · Run the spanning tree feature between the IRF fabric and the intermediate device to ensure that there is only one ARP MAD link in forwarding state. For more information about the spanning tree feature and its configuration, see Layer 2—LAN Switching Configuration Guide. · Enable the IRF fabric to change its bridge MAC address as soon as the address owner leaves. · If the intermediate device is also an IRF fabric, assign the two IRF fabrics different domain IDs for correct split detection.

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Assign a domain ID to the IRF fabric.	irf domain domain-id	The default IRF domain ID is 0.
3. Configure the IRF bridge MAC address to change as soon as the address owner leaves.	undo irf mac-address persistent	By default, the IRF bridge MAC address remains unchanged for 6 minutes after the address owner leaves.
4. Create a VLAN dedicated to ARP MAD.	vlan vlan-id	By default, only VLAN 1 exists.
5. Return to system view.	quit	N/A
6. Enter Ethernet interface view.	interface interface-type interface-number	N/A
7. Assign the port to the ARP MAD VLAN.	· Assign the port to the VLAN as an access port: port access vlan vlan-id · Assign the port to the VLAN as a trunk port: port trunk permit vlan vlan-id · Assign the port to the VLAN as a hybrid port: port hybrid vlan vlan-id { tagged \| untagged }	The link type of ARP MAD ports can be access, trunk, or hybrid. The default link type of a port is access.
8. Return to system view.	quit	N/A
9. Enter VLAN interface view.	interface vlan-interface vlan-interface-id	N/A
10. Assign the interface an IP address.	ip address ip-address { mask \| mask-length }	By default, no IP addresses are assigned to a VLAN interface.
11. Enable ARP MAD.	mad arp enable	By default, ARP MAD is disabled.

Configuring ARP MAD that uses management Ethernet ports

When you configure ARP MAD that uses management Ethernet ports, follow these restrictions and guidelines:

Category	Restrictions and guidelines
Management Ethernet ports for ARP MAD	Connect a management Ethernet port on each member device to the common Ethernet ports on the intermediate device.
ARP MAD VLAN	On the intermediate device, create a VLAN for ARP MAD, and assign the ports used for ARP MAD to the VLAN. On the IRF fabric, you do not need to assign the management Ethernet ports to the VLAN.
ARP MAD and feature configuration	· Enable the IRF fabric to change its bridge MAC address as soon as the address owner leaves. · If the intermediate device is also an IRF fabric, assign the two IRF fabrics different domain IDs for correct split detection.

To configure ARP MAD that uses management Ethernet ports:

Step	Command		Remarks
1. Enter system view.	system-view		N/A
2. Assign a domain ID to the IRF fabric.	irf domain domain-id		By default, the domain ID of an IRF fabric is 0.
3. Configure the IRF bridge MAC address to change as soon as the address owner leaves.		undo irf mac-address persistent	By default, the IRF bridge MAC address remains unchanged for 6 minutes after the address owner leaves.
4. Enter management Ethernet interface view.	interface M-GigabitEthernet interface-number		Of all management Ethernet ports on an IRF fabric, only the master's management Ethernet ports are accessible.
5. Assign an IP address to the management Ethernet port.	ip address ip-address { mask \| mask-length }		By default, no IP addresses are configured.
6. Enable ARP MAD.	mad arp enable		By default, ARP MAD is disabled.

Configuring ND MAD

When you use ND MAD, follow these guidelines:

· Do not configure ND MAD on VLAN-interface 1.

· Do not use the VLAN configured for ND MAD for any other purposes.

· If an intermediate device is used, you can use common data links as ND MAD links. If no intermediate device is used, set up dedicated ND MAD links between IRF member devices.

· If an intermediate device is used, make sure the following requirements are met:

? Run the spanning tree feature between the IRF fabric and the intermediate device. Make sure there is only one ND MAD link in forwarding state. For more information about the spanning tree feature and its configuration, see Layer 2—LAN Switching Configuration Guide.

? Enable the IRF fabric to change its bridge MAC address as soon as the address owner leaves.

? Create an ND MAD VLAN and assign the ports on the ND MAD links to the VLAN.

? If the intermediate device is also an IRF fabric, assign the two IRF fabrics different domain IDs for correct split detection.

To configure ND MAD:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Assign a domain ID to the IRF fabric.	irf domain domain-id	The default IRF domain ID is 0.
3. Configure the IRF bridge MAC address to change as soon as the address owner leaves.	undo irf mac-address persistent	By default, the IRF bridge MAC address remains unchanged for 6 minutes after the address owner leaves.
4. Create a VLAN dedicated to ND MAD.	vlan vlan-id	By default, only VLAN 1 exists.
5. Return to system view.	quit	N/A
6. Enter Ethernet interface view.	interface interface-type interface-number	N/A
7. Assign the port to the ND MAD VLAN.	· Assign the port to the VLAN as an access port: port access vlan vlan-id · Assign the port to the VLAN as a trunk port: port trunk permit vlan vlan-id · Assign the port to the VLAN as a hybrid port: port hybrid vlan vlan-id { tagged \| untagged }	The link type of ND MAD ports can be access, trunk, or hybrid. The default link type of a port is access.
8. Return to system view.	quit	N/A
9. Enter VLAN interface view.	interface vlan-interface vlan-interface-id	N/A
10. Assign the interface an IP address.	ipv6 address { ipv6-address/prefix-length \| ipv6-address prefix-length }	By default, no IPv6 addresses are assigned to a VLAN interfaces.
11. Enable ND MAD.	mad nd enable	By default, ND MAD is disabled.

Excluding an interface from the shutdown action upon detection of multi-active collision

When an IRF fabric transits to the Recovery state, the system automatically excludes the following network interfaces from being shut down:

· IRF physical interfaces.

· Interfaces used for BFD MAD.

· Member interfaces of an aggregate interface if the aggregate interface is excluded from being shut down.

You can exclude an interface from the shutdown action for management or other special purposes. For example:

· Exclude a port from the shutdown action so you can Telnet to the port for managing the device.

· Exclude a VLAN interface and its Layer 2 ports from the shutdown action so you can log in through the VLAN interface.

Configuration restrictions and guidelines

If the Layer 2 ports of a VLAN interface are distributed on multiple member devices, the exclusion operation might introduce IP collision risks. The VLAN interface might be up on both active and inactive IRF fabrics.

Configuration procedure

To configure an interface to not shut down when the IRF fabric transits to the Recovery state:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Configure an interface to not shut down when the IRF fabric transits to the Recovery state.	mad exclude interface interface-type interface-number	By default, all network interfaces on a Recovery-state IRF fabric are shut down, except for the network interfaces excluded by the system.

Recovering an IRF fabric

When the failed IRF link between two split IRF fabrics is recovered, all member devices in the inactive IRF fabric automatically join the active IRF fabric as subordinate members. The network interfaces that have been shut down by MAD automatically restore their original physical state, as shown in Figure 12.

Figure 12 Recovering the IRF fabric

If the active IRF fabric fails before the IRF link is recovered (see Figure 13), use the mad restore command on the inactive IRF fabric to recover the inactive IRF fabric. This command brings up all network interfaces that were shut down by MAD. After you repair the IRF link, the two parts merge into a unified IRF fabric.

Figure 13 Active IRF fabric fails before the IRF link is recovered

To manually recover an inactive IRF fabric:

Step	Command
1. Enter system view.	system-view
2. Recover the inactive IRF fabric.	mad restore

After the IRF fabric is recovered, all network interfaces that have been shut down by MAD come up automatically.

Removing an expansion interface card that has IRF physical interfaces

To remove an expansion interface card that provides IRF physical interfaces:

1. Perform one of the following tasks to eliminate temporary packet loss:

? Remove cables from the IRF physical interfaces on the card.

? Shut down the IRF physical interfaces on the card by using the shutdown command.

2. Remove the card.

Replacing an expansion interface card that has IRF physical interfaces

To replace the old card with a different model replacement card:

1. Shut down the IRF physical interfaces on the old card by using the shutdown command.

2. Remove the IRF port bindings that contain the physical interfaces.

3. Remove the old card, and then install the replacement card.

4. Verify that the replacement card has been correctly installed by using the display device command.

5. Reconfigure the IRF port bindings, as described in "Binding physical interfaces to IRF ports."

6. Activate the IRF port settings by using the irf-port-configuration active command.

You may skip this step if the IRF port is in UP state when you add bindings.

To replace the old card with the same model replacement card:

1. Shut down the IRF physical interfaces on the old card by using the shutdown command.

2. Remove the old card, and then install the replacement card.

3. Verify that the replacement card has been correctly installed by using the display device command.

4. Bring up the physical interfaces by using the undo shutdown command after the interface card completes startup.

Displaying and maintaining an IRF fabric

Execute display commands in any view.

Task	Command
Display information about all IRF members.	display irf
Display the IRF fabric topology.	display irf topology
Display IRF link information.	display irf link
Display IRF configuration.	display irf configuration
Display the load sharing mode for IRF links.	display irf-port load-sharing mode [ irf-port [ member-id/irf-port-number ] ]
Display MAD configuration.	display mad [ verbose ]

Configuration examples

This section provides IRF configuration examples for IRF fabrics that use different MAD mechanisms.

LACP MAD-enabled IRF configuration example

Network requirements

As shown in Figure 14, set up a four-chassis IRF fabric at the access layer of the enterprise network.

Configure LACP MAD on the multichassis aggregation to Device E, an H3C device that supports extended LACP.

Figure 14 Network diagram

Configuration procedure

1. Configure Device A:

# Shut down the physical interfaces used for IRF links. In this example, the physical interfaces are shut down in batch. For more information, see Layer 2—LAN Switching Configuration Guide.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 1/0/49 to ten-gigabitethernet 1/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 1/0/49 and Ten-GigabitEthernet 1/0/50 to IRF-port 1/1.

[Sysname] irf-port 1/1

[Sysname-irf-port1/1] port group interface ten-gigabitethernet 1/0/49

[Sysname-irf-port1/1] port group interface ten-gigabitethernet 1/0/50

[Sysname-irf-port1/1] quit

# Bind Ten-GigabitEthernet 1/0/51 and Ten-GigabitEthernet 1/0/52 to IRF-port 1/2.

[Sysname] irf-port 1/2

[Sysname-irf-port1/2] port group interface ten-gigabitethernet 1/0/51

[Sysname-irf-port1/2] port group interface ten-gigabitethernet 1/0/52

[Sysname-irf-port1/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 1/0/49 to ten-gigabitethernet 1/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

2. Configure Device B:

# Change the member ID of Device B to 2 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 2

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device B to Device A as shown in Figure 14, and log in to Device B. (Details not shown.)

# Shut down the physical interfaces for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 2/0/49 to ten-gigabitethernet 2/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 2/0/49 and Ten-GigabitEthernet 2/0/50 to IRF-port 2/1.

[Sysname] irf-port 2/1

[Sysname-irf-port2/1] port group interface ten-gigabitethernet 2/0/49

[Sysname-irf-port2/1] port group interface ten-gigabitethernet 2/0/50

[Sysname-irf-port2/1] quit

# Bind Ten-GigabitEthernet 2/0/51 and Ten-GigabitEthernet 2/0/52 to IRF-port 2/2.

[Sysname] irf-port 2/2

[Sysname-irf-port2/2] port group interface ten-gigabitethernet 2/0/51

[Sysname-irf-port2/2] port group interface ten-gigabitethernet 2/0/52

[Sysname-irf-port2/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 2/0/49 to ten-gigabitethernet 2/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

The two devices perform master election, and the one that has lost the election reboots to form an IRF fabric with the master.

3. Configure Device C:

# Change the member ID of Device C to 3 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 3

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device C to Device A as shown in Figure 14, and log in to Device C. (Details not shown.)

# Shut down the physical interfaces for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 3/0/49 to ten-gigabitethernet 3/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 3/0/49 and Ten-GigabitEthernet 3/0/50 to IRF-port 3/1.

[Sysname] irf-port 3/1

[Sysname-irf-port3/1] port group interface ten-gigabitethernet 3/0/49

[Sysname-irf-port3/1] port group interface ten-gigabitethernet 3/0/50

[Sysname-irf-port3/1] quit

# Bind Ten-GigabitEthernet 3/0/51 and Ten-GigabitEthernet 3/0/52 to IRF-port 3/2.

[Sysname] irf-port 3/2

[Sysname-irf-port3/2] port group interface ten-gigabitethernet 3/0/51

[Sysname-irf-port3/2] port group interface ten-gigabitethernet 3/0/52

[Sysname-irf-port3/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 3/0/49 to ten-gigabitethernet 3/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

Device C reboots to join the IRF fabric.

4. Configure Device D:

# Change the member ID of Device D to 4 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 4

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device D to Device B and Device C as shown in Figure 14, and log in to Device D. (Details not shown.)

# Shut down the physical interfaces.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 4/0/49 to ten-gigabitethernet 4/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 4/0/49 and Ten-GigabitEthernet 4/0/50 to IRF-port 4/1.

[Sysname] irf-port 4/1

[Sysname-irf-port4/1] port group interface ten-gigabitethernet 4/0/49

[Sysname-irf-port4/1] port group interface ten-gigabitethernet 4/0/50

[Sysname-irf-port4/1] quit

# Bind Ten-GigabitEthernet 4/0/51 and Ten-GigabitEthernet 4/0/52 to IRF-port 4/2.

[Sysname] irf-port 4/2

[Sysname-irf-port4/2] port group interface ten-gigabitethernet 4/0/51

[Sysname-irf-port4/2] port group interface ten-gigabitethernet 4/0/52

[Sysname-irf-port4/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 4/0/49 to ten-gigabitethernet 4/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

Device D reboots to join the IRF fabric. A four-chassis IRF fabric is formed.

5. Configure LACP MAD on the IRF fabric:

# Set the domain ID of the IRF fabric to 1.

<Sysname> system-view

[Sysname] irf domain 1

# Create a dynamic aggregate interface and enable LACP MAD.

[Sysname] interface bridge-aggregation 2

[Sysname-Bridge-Aggregation2] link-aggregation mode dynamic

[Sysname-Bridge-Aggregation2] mad enable

You need to assign a domain ID (range: 0-4294967295)

[Current domain is: 1]:

The assigned domain ID is: 1

Info: MAD LACP only enable on dynamic aggregation interface.

[Sysname-Bridge-Aggregation2] quit

# Assign GigabitEthernet 1/0/1, GigabitEthernet 2/0/1, GigabitEthernet 3/0/1, and GigabitEthernet 4/0/1 to the aggregate interface.

[Sysname] interface range gigabitethernet 1/0/1 gigabitethernet 2/0/1 gigabitethernet 3/0/1 gigabitethernet 4/0/1

[Sysname-if-range] port link-aggregation group 2

[Sysname-if-range] quit

6. Configure Device E as the intermediate device:

CAUTION:

If the intermediate device is also an IRF fabric, assign the two IRF fabrics different domain IDs for correct split detection. False detection causes IRF split.

# Create a dynamic aggregate interface.

<Sysname> system-view

[Sysname] interface bridge-aggregation 2

[Sysname-Bridge-Aggregation2] link-aggregation mode dynamic

[Sysname-Bridge-Aggregation2] quit

# Assign GigabitEthernet 1/0/1, GigabitEthernet 1/0/2, GigabitEthernet 1/0/3, and GigabitEthernet 1/0/4 to the aggregate interface.

[Sysname] interface range gigabitethernet 1/0/1 to gigabitethernet 1/0/4

[Sysname-if-range] port link-aggregation group 2

[Sysname-if-range] quit

BFD MAD-enabled IRF configuration example

Network requirements

As shown in Figure 15, set up a four-chassis IRF fabric at the distribution layer of the enterprise network.

· Configure BFD MAD on the IRF fabric and set up BFD MAD links between each member device and the intermediate device.

· Disable the spanning tree feature on the ports used for BFD MAD, because the two features conflict with each other.

Figure 15 Network diagram

Configuration procedure

1. Configure Device A:

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 1/0/49 to ten-gigabitethernet 1/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 1/0/49 and Ten-GigabitEthernet 1/0/50 to IRF-port 1/1.

[Sysname] irf-port 1/1

[Sysname-irf-port1/1] port group interface ten-gigabitethernet 1/0/49

[Sysname-irf-port1/1] port group interface ten-gigabitethernet 1/0/50

[Sysname-irf-port1/1] quit

# Bind Ten-GigabitEthernet 1/0/51 and Ten-GigabitEthernet 1/0/52 to IRF-port 1/2.

[Sysname] irf-port 1/2

[Sysname-irf-port1/2] port group interface ten-gigabitethernet 1/0/51

[Sysname-irf-port1/2] port group interface ten-gigabitethernet 1/0/52

[Sysname-irf-port1/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 1/0/49 to ten-gigabitethernet 1/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

2. Configure Device B:

# Change the member ID of Device B to 2 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 2

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device B to Device A as shown in Figure 15, and log in to Device B. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 2/0/49 to ten-gigabitethernet 2/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 2/0/49 and Ten-GigabitEthernet 2/0/50 to IRF-port 2/1.

[Sysname] irf-port 2/1

[Sysname-irf-port2/1] port group interface ten-gigabitethernet 2/0/49

[Sysname-irf-port2/1] port group interface ten-gigabitethernet 2/0/50

[Sysname-irf-port2/1] quit

# Bind Ten-GigabitEthernet 2/0/51 and Ten-GigabitEthernet 2/0/52 to IRF-port 2/2.

[Sysname] irf-port 2/2

[Sysname-irf-port2/2] port group interface ten-gigabitethernet 2/0/51

[Sysname-irf-port2/2] port group interface ten-gigabitethernet 2/0/52

[Sysname-irf-port2/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 2/0/49 to ten-gigabitethernet 2/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

The two devices perform master election, and the one that has lost the election reboots to form an IRF fabric with the master.

3. Configure Device C:

# Change the member ID of Device C to 3 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 3

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device C to Device A as shown in Figure 15, and log in to Device C. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 3/0/49 to ten-gigabitethernet 3/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 3/0/49 and Ten-GigabitEthernet 3/0/50 to IRF-port 3/1.

[Sysname] irf-port 3/1

[Sysname-irf-port3/1] port group interface ten-gigabitethernet 3/0/49

[Sysname-irf-port3/1] port group interface ten-gigabitethernet 3/0/50

[Sysname-irf-port3/1] quit

# Bind Ten-GigabitEthernet 3/0/51 and Ten-GigabitEthernet 3/0/52 to IRF-port 3/2.

[Sysname] irf-port 3/2

[Sysname-irf-port3/2] port group interface ten-gigabitethernet 3/0/51

[Sysname-irf-port3/2] port group interface ten-gigabitethernet 3/0/52

[Sysname-irf-port3/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 3/0/49 to ten-gigabitethernet 3/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

Device C reboots to join the IRF fabric.

4. Configure Device D:

# Change the member ID of Device D to 4 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 4

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device D to Device B and Device C as shown in Figure 15, and log in to Device D. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 4/0/49 to ten-gigabitethernet 4/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 4/0/49 and Ten-GigabitEthernet 4/0/50 to IRF-port 4/1.

[Sysname] irf-port 4/1

[Sysname-irf-port4/1] port group interface ten-gigabitethernet 4/0/49

[Sysname-irf-port4/1] port group interface ten-gigabitethernet 4/0/50

[Sysname-irf-port4/1] quit

# Bind Ten-GigabitEthernet 4/0/51 and Ten-GigabitEthernet 4/0/52 to IRF-port 4/2.

[Sysname] irf-port 4/2

[Sysname-irf-port4/2] port group interface ten-gigabitethernet 4/0/51

[Sysname-irf-port4/2] port group interface ten-gigabitethernet 4/0/52

[Sysname-irf-port4/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 4/0/49 to ten-gigabitethernet 4/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

Device D reboots to join the IRF fabric. A four-chassis IRF fabric is formed.

5. Configure BFD MAD on the IRF fabric:

# Create VLAN 3, and add GigabitEthernet 1/0/1, GigabitEthernet 2/0/1, GigabitEthernet 3/0/1, and GigabitEthernet 4/0/1 to VLAN 3.

[Sysname] vlan 3

[Sysname-vlan3] port gigabitethernet 1/0/1 gigabitethernet 2/0/1 gigabitethernet 3/0/1 gigabitethernet 4/0/1

[Sysname-vlan3] quit

# Create VLAN-interface 3, and configure a MAD IP address for each member device on the VLAN interface.

[Sysname] interface vlan-interface 3

[Sysname-Vlan-interface3] mad bfd enable

[Sysname-Vlan-interface3] mad ip address 192.168.2.1 24 member 1

[Sysname-Vlan-interface3] mad ip address 192.168.2.2 24 member 2

[Sysname-Vlan-interface3] mad ip address 192.168.2.3 24 member 3

[Sysname-Vlan-interface3] mad ip address 192.168.2.4 24 member 4

[Sysname-Vlan-interface3] quit

# Disable the spanning tree feature on GigabitEthernet 1/0/1, GigabitEthernet 2/0/1, GigabitEthernet 3/0/1, and GigabitEthernet 4/0/1.

[Sysname] interface range gigabitethernet 1/0/1 gigabitethernet 2/0/1 gigabitethernet 3/0/1 gigabitethernet 4/0/1

[Sysname-if-range] undo stp enable

[Sysname-if-range] quit

6. Configure Device E as the intermediate device:

CAUTION:

If the intermediate device is also an IRF fabric, assign the two IRF fabrics different domain IDs for correct split detection. False detection causes IRF split.

# Create VLAN 3, and assign GigabitEthernet 1/0/1, GigabitEthernet 1/0/2, GigabitEthernet 1/0/3, and GigabitEthernet 1/0/4 to VLAN 3 for forwarding BFD MAD packets.

<DeviceE> system-view

[DeviceE] vlan 3

[DeviceE-vlan3] port gigabitethernet 1/0/1 to gigabitethernet 1/0/4

[DeviceE-vlan3] quit

ARP MAD-enabled IRF configuration example

Network requirements

As shown in Figure 16, set up a four-chassis IRF fabric in the enterprise network.

· Configure ARP MAD on the IRF fabric and use the links connected to Device E for transmitting ARP MAD packets.

· To prevent loops, run the spanning tree feature between Device E and the IRF fabric.

Figure 16 Network diagram

Configuration procedure

1. Configure Device A:

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 1/0/49 to ten-gigabitethernet 1/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 1/0/49 and Ten-GigabitEthernet 1/0/50 to IRF-port 1/1.

[Sysname] irf-port 1/1

[Sysname-irf-port1/1] port group interface ten-gigabitethernet 1/0/49

[Sysname-irf-port1/1] port group interface ten-gigabitethernet 1/0/50

[Sysname-irf-port1/1] quit

# Bind Ten-GigabitEthernet 1/0/51 and Ten-GigabitEthernet 1/0/52 to IRF-port 1/2.

[Sysname] irf-port 1/2

[Sysname-irf-port1/2] port group interface ten-gigabitethernet 1/0/51

[Sysname-irf-port1/2] port group interface ten-gigabitethernet 1/0/52

[Sysname-irf-port1/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 1/0/49 to ten-gigabitethernet 1/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

2. Configure Device B:

# Change the member ID of Device B to 2 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 2

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device B to Device A as shown in Figure 16, and log in to Device B. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 2/0/49 to ten-gigabitethernet 2/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 2/0/49 and Ten-GigabitEthernet 2/0/50 to IRF-port 2/1.

[Sysname] irf-port 2/1

[Sysname-irf-port2/1] port group interface ten-gigabitethernet 2/0/49

[Sysname-irf-port2/1] port group interface ten-gigabitethernet 2/0/50

[Sysname-irf-port2/1] quit

# Bind Ten-GigabitEthernet 2/0/51 and Ten-GigabitEthernet 2/0/52 to IRF-port 2/2.

[Sysname] irf-port 2/2

[Sysname-irf-port2/2] port group interface ten-gigabitethernet 2/0/51

[Sysname-irf-port2/2] port group interface ten-gigabitethernet 2/0/52

[Sysname-irf-port2/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 2/0/49 to ten-gigabitethernet 2/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

The two devices perform master election, and the one that has lost the election reboots to form an IRF fabric with the master.

3. Configure Device C:

# Change the member ID of Device C to 3 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 3

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device C to Device A as shown in Figure 16, and log in to Device C. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 3/0/49 to ten-gigabitethernet 3/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 3/0/49 and Ten-GigabitEthernet 3/0/50 to IRF-port 3/1.

[Sysname] irf-port 3/1

[Sysname-irf-port3/1] port group interface ten-gigabitethernet 3/0/49

[Sysname-irf-port3/1] port group interface ten-gigabitethernet 3/0/50

[Sysname-irf-port3/1] quit

# Bind Ten-GigabitEthernet 3/0/51 and Ten-GigabitEthernet 3/0/52 to IRF-port 3/2.

[Sysname] irf-port 3/2

[Sysname-irf-port3/2] port group interface ten-gigabitethernet 3/0/51

[Sysname-irf-port3/2] port group interface ten-gigabitethernet 3/0/52

[Sysname-irf-port3/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 3/0/49 to ten-gigabitethernet 3/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

Device C reboots to join the IRF fabric.

4. Configure Device D:

# Change the member ID of Device D to 4 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 4

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device D to Device B and Device C as shown in Figure 16, and log in to Device D. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 4/0/49 to ten-gigabitethernet 4/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 4/0/49 and Ten-GigabitEthernet 4/0/50 to IRF-port 4/1.

[Sysname] irf-port 4/1

[Sysname-irf-port4/1] port group interface ten-gigabitethernet 4/0/49

[Sysname-irf-port4/1] port group interface ten-gigabitethernet 4/0/50

[Sysname-irf-port4/1] quit

# Bind Ten-GigabitEthernet 4/0/51 and Ten-GigabitEthernet 4/0/52 to IRF-port 4/2.

[Sysname] irf-port 4/2

[Sysname-irf-port4/2] port group interface ten-gigabitethernet 4/0/51

[Sysname-irf-port4/2] port group interface ten-gigabitethernet 4/0/52 [Sysname-irf-port4/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 4/0/49 to ten-gigabitethernet 4/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

Device D reboots to join the IRF fabric. A four-chassis IRF fabric is formed.

5. Configure ARP MAD on the IRF fabric:

# Enable the spanning tree feature globally. Map the ARP MAD VLAN to MSTI 1 in the MST region.

<Sysname> system-view

[Sysname] stp global enable

[Sysname] stp region-configuration

[Sysname-mst-region] region-name arpmad

[Sysname-mst-region] instance 1 vlan 3

[Sysname-mst-region] active region-configuration

[Sysname-mst-region] quit

# Configure the IRF fabric to change its bridge MAC address as soon as the address owner leaves.

[Sysname] undo irf mac-address persistent

# Set the domain ID of the IRF fabric to 1.

[Sysname] irf domain 1

# Create VLAN 3, and assign GigabitEthernet 1/0/1, GigabitEthernet 2/0/1, GigabitEthernet 3/0/1, and GigabitEthernet 4/0/1 to VLAN 3.

[Sysname] vlan 3

[Sysname-vlan3] port gigabitethernet 1/0/1 gigabitethernet 2/0/1 gigabitethernet 3/0/1 gigabitethernet 4/0/1

[Sysname-vlan3] quit

# Create VLAN-interface 3, assign it an IP address, and enable ARP MAD on the interface.

[Sysname] interface vlan-interface 3

[Sysname-Vlan-interface3] ip address 192.168.2.1 24

[Sysname-Vlan-interface3] mad arp enable

You need to assign a domain ID (range: 0-4294967295)

[Current domain is: 1]:

The assigned domain ID is: 1

6. Configure Device E as the intermediate device:

CAUTION:

If the intermediate device is also in an IRF fabric, assign the two IRF fabrics different domain IDs for correct split detection. False detection causes IRF split.

# Enable the spanning tree feature globally. Map the ARP MAD VLAN to MSTI 1 in the MST region.

<DeviceE> system-view

[DeviceE] stp global enable

[DeviceE] stp region-configuration

[DeviceE-mst-region] region-name arpmad

[DeviceE-mst-region] instance 1 vlan 3

[DeviceE-mst-region] active region-configuration

[DeviceE-mst-region] quit

# Create VLAN 3, and assign GigabitEthernet 1/0/1, GigabitEthernet 1/0/2, GigabitEthernet 1/0/3, and GigabitEthernet 1/0/4 to VLAN 3 for forwarding ARP MAD packets.

[DeviceE] vlan 3

[DeviceE-vlan3] port gigabitethernet 1/0/1 to gigabitethernet 1/0/4

[DeviceE-vlan3] quit

ND MAD-enabled IRF configuration example

Network requirements

As shown in Figure 17, set up a four-chassis IRF fabric in the IPv6 enterprise network.

· Configure ND MAD on the IRF fabric and use the links connected to Device E for transmitting ND MAD packets.

· To prevent loops, run the spanning tree feature between Device E and the IRF fabric.

Figure 17 Network diagram

Configuration procedure

1. Configure Device A:

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 1/0/49 to ten-gigabitethernet 1/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 1/0/49 and Ten-GigabitEthernet 1/0/50 to IRF-port 1/1.

[Sysname] irf-port 1/1

[Sysname-irf-port1/1] port group interface ten-gigabitethernet 1/0/49

[Sysname-irf-port1/1] port group interface ten-gigabitethernet 1/0/50

[Sysname-irf-port1/1] quit

# Bind Ten-GigabitEthernet 1/0/51 and Ten-GigabitEthernet 1/0/52 to IRF-port 1/2.

[Sysname] irf-port 1/2

[Sysname-irf-port1/2] port group interface ten-gigabitethernet 1/0/51

[Sysname-irf-port1/2] port group interface ten-gigabitethernet 1/0/52

[Sysname-irf-port1/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 1/0/49 to ten-gigabitethernet 1/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

2. Configure Device B:

# Change the member ID of Device B to 2 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 2

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device B to Device A as shown in Figure 17, and log in to Device B. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 2/0/49 to ten-gigabitethernet 2/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 2/0/49 and Ten-GigabitEthernet 2/0/50 to IRF-port 2/1.

[Sysname] irf-port 2/1

[Sysname-irf-port2/1] port group interface ten-gigabitethernet 2/0/49

[Sysname-irf-port2/1] port group interface ten-gigabitethernet 2/0/50

[Sysname-irf-port2/1] quit

# Bind Ten-GigabitEthernet 2/0/51 and Ten-GigabitEthernet 2/0/52 to IRF-port 2/2.

[Sysname] irf-port 2/2

[Sysname-irf-port2/2] port group interface ten-gigabitethernet 2/0/51

[Sysname-irf-port2/2] port group interface ten-gigabitethernet 2/0/52

[Sysname-irf-port2/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 2/0/49 to ten-gigabitethernet 2/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

The two devices perform master election, and the one that has lost the election reboots to form an IRF fabric with the master.

3. Configure Device C:

# Change the member ID of Device C to 3 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 3

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device C to Device A as shown in Figure 17, and log in to Device C. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 3/0/49 to ten-gigabitethernet 3/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 3/0/49 and Ten-GigabitEthernet 3/0/50 to IRF-port 3/1.

[Sysname] irf-port 3/1

[Sysname-irf-port3/1] port group interface ten-gigabitethernet 3/0/49

[Sysname-irf-port3/1] port group interface ten-gigabitethernet 3/0/50

[Sysname-irf-port3/1] quit

# Bind Ten-GigabitEthernet 3/0/51 and Ten-GigabitEthernet 3/0/52 to IRF-port 3/2.

[Sysname] irf-port 3/2

[Sysname-irf-port3/2] port group interface ten-gigabitethernet 3/0/51

[Sysname-irf-port3/2] port group interface ten-gigabitethernet 3/0/52

[Sysname-irf-port3/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 3/0/49 to ten-gigabitethernet 3/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

Device C reboots to join the IRF fabric.

4. Configure Device D:

# Change the member ID of Device D to 4 and reboot the device to have the change take effect.

<Sysname> system-view

[Sysname] irf member 1 renumber 4

Renumbering the member ID may result in configuration change or loss. Continue? [Y/N]:y

[Sysname] quit

<Sysname> reboot

# Connect Device D to Device B and Device C as shown in Figure 17, and log in to Device D. (Details not shown.)

# Shut down the physical interfaces used for IRF links.

<Sysname> system-view

[Sysname] interface range ten-gigabitethernet 4/0/49 to ten-gigabitethernet 4/0/52

[Sysname-if-range] shutdown

[Sysname-if-range] quit

# Bind Ten-GigabitEthernet 4/0/49 and Ten-GigabitEthernet 4/0/50 to IRF-port 4/1.

[Sysname] irf-port 4/1

[Sysname-irf-port4/1] port group interface ten-gigabitethernet 4/0/49

[Sysname-irf-port4/1] port group interface ten-gigabitethernet 4/0/50

[Sysname-irf-port4/1] quit

# Bind Ten-GigabitEthernet 4/0/51 and Ten-GigabitEthernet 4/0/52 to IRF-port 4/2.

[Sysname] irf-port 4/2

[Sysname-irf-port4/2] port group interface ten-gigabitethernet 4/0/51

[Sysname-irf-port4/2] port group interface ten-gigabitethernet 4/0/52

[Sysname-irf-port4/2] quit

# Bring up the physical interfaces and save the configuration.

[Sysname] interface range ten-gigabitethernet 4/0/49 to ten-gigabitethernet 4/0/52

[Sysname-if-range] undo shutdown

[Sysname-if-range] quit

[Sysname] save

# Activate the IRF port configuration.

[Sysname] irf-port-configuration active

Device D reboots to join the IRF fabric. A four-chassis IRF fabric is formed.

5. Configure ND MAD on the IRF fabric:

# Enable the spanning tree feature globally. Map the ND MAD VLAN to MSTI 1 in the MST region.

<Sysname> system-view

[Sysname] stp global enable

[Sysname] stp region-configuration

[Sysname-mst-region] region-name ndmad

[Sysname-mst-region] instance 1 vlan 3

[Sysname-mst-region] active region-configuration

[Sysname-mst-region] quit

# Configure the IRF fabric to change its bridge MAC address as soon as the address owner leaves.

[Sysname] undo irf mac-address persistent

# Set the domain ID of the IRF fabric to 1.

[Sysname] irf domain 1

# Create VLAN 3, and add GigabitEthernet 1/0/1, GigabitEthernet 2/0/1, GigabitEthernet 3/0/1, and GigabitEthernet 4/0/1 to VLAN 3.

[Sysname] vlan 3

[Sysname-vlan3] port gigabitethernet 1/0/1 gigabitethernet 2/0/1 gigabitethernet 3/0/1 gigabitethernet 4/0/1

[Sysname-vlan3] quit

# Create VLAN-interface 3, assign it an IPv6 address, and enable ND MAD on the interface.

[Sysname] interface vlan-interface 3

[Sysname-Vlan-interface3] ipv6 address 2001::1 64

[Sysname-Vlan-interface3] mad nd enable

You need to assign a domain ID (range: 0-4294967295)

[Current domain is: 1]:

The assigned domain ID is: 1

6. Configure Device E as the intermediate device:

CAUTION:

If the intermediate device is also in an IRF fabric, assign the two IRF fabrics different domain IDs for correct split detection. False detection causes IRF split.

# Enable the spanning tree feature globally. Map the ND MAD VLAN to MSTI 1 in the MST region.

<DeviceE> system-view

[DeviceE] stp global enable

[DeviceC] stp region-configuration

[DeviceC-mst-region] region-name ndmad

[DeviceC-mst-region] instance 1 vlan 3

[DeviceC-mst-region] active region-configuration

[DeviceC-mst-region] quit

# Create VLAN 3, and add GigabitEthernet 1/0/1, GigabitEthernet 1/0/2, GigabitEthernet 1/0/3, and GigabitEthernet 1/0/4 to VLAN 3 for forwarding ND MAD packets.

[DeviceE] vlan 3

[DeviceE-vlan3] port gigabitethernet 1/0/1 to gigabitethernet 1/0/4

[DeviceE-vlan3] quit

Setting up an IRF 3.1 system

Overview

IRF 3.1 integrates multiple lower-layer devices with a higher-layer IRF fabric to provide high-density, low-cost connectivity at the access layer. IRF 3.1 is implemented based on IEEE 802.1BR.

In an IRF 3.1 system, the higher-layer IRF fabric is called the parent fabric and the lower-layer devices are called bridge port extenders (PEXs). You can manage and configure the PEXs from the parent fabric as if they were interface cards on the parent fabric.

Typically, IRF 3.1 works at the access layer of data centers and large-scale enterprise networks. As shown in Figure 18, the access layer of a network is virtualized into an IRF 3.1 system. The system contains one parent fabric (a two-chassis IRF fabric) and multiple PEXs to provide connectivity for servers and hosts.

Figure 18 IRF 3.1 application scenario

IRF 3.1 provides the following benefits:

· Simplified topology—Devices in an IRF 3.1 system appear as one node. For redundancy and load balancing, a downstream or upstream device can connect to the IRF 3.1 system through multichassis link aggregation. Together with link aggregation, IRF 3.1 creates a loop-free Layer 2 network. The spanning tree feature is not needed among devices in the IRF 3.1 system or on the link aggregations. IRF 3.1 also simplifies the Layer 3 network topology because it reduces the number of routing peers. The network topology does not change when a device is added to or removed from the IRF 3.1 system.

· Single point of management—An IRF 3.1 system is accessible at a single IP address on the network. You can use this IP address to log in through any network port to manage all the devices in the system. For an SNMP NMS, an IRF 3.1 system is one managed network node.

· Network scalability and resiliency—You can increase the number of ports in an IRF 3.1 system by adding PEXs without changing network topology.

· High availability—Each PEX has multiple high-speed physical ports for uplink connectivity to the parent fabric. The links on these ports are aggregated and load balanced automatically.

· Decreased TCO—IRF 3.1 decreases hardware investments and management costs. In an IRF 3.1 system, the parent fabric performs all the management and routing functions, and the PEXs only forward traffic. You can add low-performance devices as PEXs to an IRF 3.1 system for network scalability.

· High software compatibility—The software versions of the parent fabric and PEXs are highly compatible. You can independently upgrade software for the parent and PEXs.

Network topology

One tier of PEXs

As shown in Figure 19, each PEX is directly connected to the parent fabric through a Layer 2 aggregate interface in dynamic aggregation mode. The parent fabric only has one tier of PEXs. A PEX does not have a lower-tier PEX. The PEXs cannot be connected to each other.

Figure 19 IRF 3.1 network topology with one tier of PEXs

Multiple tiers of PEXs

NOTE:

This feature is not available for S5130-HI PEXs. An IRF 3.1 system can contain only one tier of S5130-HI PEXs.

As shown in Figure 20, a PEX is connected to the parent fabric or to an upper-tier PEX through a Layer 2 aggregate interface in dynamic aggregation mode. The PEXs directly connected to the parent fabric are tier-1 PEXs. The PEXs connected to tier-1 PEXs are tier-2 PEXs. A lower-tier PEX can be connected only to one upper-tier PEX. Except for the cascade links, no other links are allowed among PEXs.

Figure 20 IRF 3.1 network topology with two tiers of PEXs

Basic concepts

IRF 3.1 includes IRF concepts and adds the concepts in this section.

IRF 3.1 roles

The devices in an IRF 3.1 system have the following roles:

· Parent fabric—Higher-layer single-chassis or multichassis IRF fabric that controls the entire IRF 3.1 system, including PEXs. Each IRF 3.1 system has one parent fabric.

· Parent device—Member devices in the parent fabric.

· Master device—Controls and manages the entire IRF 3.1 system, including all parent devices and PEXs. The master device in the IRF fabric is also the master device for the IRF 3.1 system. You configure all devices (including PEXs and parent devices) from the master device.

· PEX—Operates as I/O modules of the parent fabric to receive and transmit traffic. All forwarding decisions are made on the parent fabric. PEXs can be configured only on the parent fabric. Table 3 shows the operating states of PEXs.

Table 3 PEX operating states

State	Description
Offline	The PEX is offline. The PEX and the parent fabric have not established a PE CSP connection. The PEX cannot be managed by the parent fabric.
Online	The PEX is online. An online PEX has been discovered by the parent fabric through LLDP and has finished Port Extender Control and Status Protocol (PE CSP) negotiation with the parent fabric.

Operating modes

The device supports auto, PEX, and switch modes as described in Table 4.

Table 4 IRF 3.1 operating modes

Mode	Application scenario	Description
auto	The device is planned to join an IRF 3.1 system and operates as a PEX.	When the device detects LLDP packets from the parent fabric, it automatically reboots, starts up with factory defaults, and operates as a PEX. Before changing to a PEX, the device operates as an independent node.
PEX	The device is planned to join an IRF 3.1 system and operates as a PEX.	The device operates as a PEX and acts as an interface card on the parent fabric.
switch	The device is planned to be an independent device or a parent device in an IRF 3.1 system.	The device operates as an independent node or a parent device in an IRF 3.1 system. The device does not change to a PEX even if it receives protocol packets from a parent device.

Cascade port

A cascade port is a Layer 2 dynamic aggregate interface with PEX connection capability enabled. A tier-1 cascade port connects the parent fabric to a tier-1 PEX. A lower-tier cascade port connects an upper-tier PEX to a lower-tier PEX. The physical interfaces assigned to a cascade port are cascade member interfaces.

Upstream port

An upstream port is a Layer 2 dynamic aggregate interface automatically created on a lower-tier device for upper-tier device connection. The aggregate interface automatically aggregates physical interfaces that connect the lower-tier device to the cascade member interfaces of the upper-tier device.

PEX group

A PEX group contains a group of PEXs that are connected to cascade ports assigned to the same PEX group. Lower-tier PEXs must be assigned to the same PEX group as their upper-tier PEX.

Extended port

In an IRF 3.1 system, the physical interfaces on PEXs are called extended ports, except for the physical interfaces aggregated in the upstream ports.

Layer 2 extended-link aggregate interface

A Layer 2 extended-link aggregate interface aggregates a group of extended ports. The aggregation group of a Layer 2 extended-link aggregate interface is a Layer 2 extended-link aggregation group.

Layer 2 extended-link aggregate interfaces can act as cascade ports for lower-tier PEX connection or interfaces that forward service traffic.

Only extended ports of PEXs in the same PEX group and at the same tier can be assigned to the same extended-link aggregation group.

For more information about extended-link aggregate interfaces, see Ethernet link aggregation configuration in Layer 2—LAN Switching Configuration Guide.

Virtual chassis number and virtual slot number

For management purposes, each PEX is assigned to a unique virtual chassis on the parent fabric. A PEX is managed as an interface card on its virtual chassis. The slot number for the PEX is the IRF member ID of the PEX.

The virtual chassis number and slot number are included as the first two segments of the interface numbers on the PEX. For example, a PEX has an interface numbered 1/0/1 before it is added to an IRF 3.1 system. After it is added to chassis 100 on an IRF 3.1 system, the interface number changes to 100/1/0/1.

Virtual chassis numbers and slot numbers are assigned by distributed parent devices in IRF mode, such as the S12500-X switches.

Virtual slot number

Each PEX is identified by a unique virtual slot number in an IRF 3.1 system.

After a PEX joins an IRF 3.1 system, the first segment in its interface numbers changes to the virtual slot number assigned to the PEX. For example, a PEX has an interface numbered 1/0/1 before it is added to an IRF 3.1 system. After it is added to an IRF 3.1 system as slot 100, the interface number changes to 100/0/1.

Virtual slot numbers are assigned by centralized IRF-capable parent devices, scuh as the S6800 switches.

IRF 3.1 system setup process

Neighbor discovery

After you finish configuration on the parent fabric and a PEX and the PEX link is up, the parent fabric and the PEX send LLDP packets to each other for neighbor discovery.

An upper-tier PEX transparently forwards LLDP packets for its lower-tier PEXs and the parent fabric to discover each other.

PE CSP connection establishment

After the parent fabric and the PEX finish neighbor discovery, they send PE CSP Open requests to each other. If the parent fabric and the PEX can receive PE CSP Open responses from each other within 60 seconds, the connection between them is established.

An upper-tier PEX transparently forwards PE CSP Open requests and responses for its lower-tier PEXs and the parent fabric to establish PE CSP connections.

PEX registration

After the connection is established between the parent and PEX, the PEX uses the following process to join the IRF 3.1 system:

1. The PEX requests to register with the parent fabric. The parent fabric assigns the configured virtual slot number or virtual chassis number to the PEX.

2. The PEX requests to create its extended ports on the parent fabric. After receiving the request, the parent fabric creates the extended ports of the PEX on the parent fabric and assigns an E-channel Identifier (ECID) to each port. The ECID must be unique in the PEX group. At the same time, the interface attributes such as link state, duplex state, and rate are synchronized from the PEX to the parent fabric.

PEX link maintenance

The parent fabric and the PEX use Layer 2 aggregate interfaces in dynamic aggregation mode to connect each other. The Layer 2 aggregate interface uses LACP and PE CSP to detect and maintain link status. The PEX is offline when the aggregate interface is down or when the parent fabric and PEX do not receive PE CSP responses from each other within 60 seconds. For the PEX to come online again, the parent fabric and PEX must send PE CSP Open requests to each other and can receive Open responses from each other.

Configuration management

An IRF 3.1 system manages all its settings (including settings for PEXs) on the master device. You can configure and manage PEXs from the master device. The running configuration on the master device has all settings in the IRF 3.1 system, including settings for PEXs. When a PEX reboots or is added, the master device issues the running configuration of the virtual chassis or slot to the PEX.

Data forwarding

When PEX local forwarding is enabled for a PEX, the PEX performs local forwarding for Layer 2 unicast packets with known MAC addresses. For other packets, the PEX forwards them to the parent fabric for processing.

When PEX local forwarding is disabled for a PEX, the PEX sends any incoming traffic to the parent fabric. The parent fabric makes forwarding decisions and sends the traffic to the outgoing interfaces (see Figure 21).

When the PEX receives a packet, it tags the packet with an E-tag. The E-tag carries the ECID of the interface that receives the packet. IRF 3.1 forwards the packet based on the ECID within the IRF 3.1 system. When the packet leaves the IRF 3.1 system, the E-tag is removed.

Figure 21 Data forwarding model

Protocols and standards

IEEE 802.1BR, Virtual Bridged Local Area Networks—Bridge Port Extension

Feature and hardware compatibility

The S5130-HI switches can act only as PEXs.

Configuration restrictions and guidelines

For a successful IRF 3.1 system setup, read the configuration restrictions and guidelines carefully before you connect and set up a PEX.

PEX upstream member interface requirements

Only specific high-speed physical interfaces can be used as upstream member interfaces on a PEX. On the S5130-HI PEXs, the four SFP+ ports on the front panel can be used as upstream member interfaces.

PEX upstream port guidelines

You do not need to create a Layer 2 aggregate interface for a lower-tier device to connect an upper-tier device. The system automatically creates a Layer 2 aggregate interface in dynamic aggregation mode as the upstream port. The physical interfaces connected to the cascade member interfaces of the upper-tier device are all assigned to the aggregation group automatically.

PEX IRF member ID restrictions

If a PEX is an IRF fabric, the IRF member ID must be in the range of 1 to 4. An IRF 3.1 system supports only single-member IRF fabrics as PEXs in the current software version.

PEX maintenance

Do not log in to a PEX directly to configure the PEX. You can configure the PEX only on the parent fabric.

Configuring the device as a PEX

About configuring the device as a PEX

For the device to operate as a PEX, set the device operating mode to auto or PEX.

If you set the operating mode to auto, the device automatically reboots with factory defaults when it detects LLDP packets from a parent device. After the reboot, the device operates as a PEX.

If you set the operating mode to PEX, you must save the running configuration and manually reboot the device for the mode to take effect. The device will start up with the factory defaults. After the reboot, the device operates as a PEX.

Setting the operating mode to auto

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the operating mode to auto.	pex system-working-mode auto	By default, the device operates in auto mode. The device can automatically change to a PEX upon receiving LLDP packets from a parent device.
3. (Optional.) Save the running configuration.	save	Save the running configuration to the next-startup configuration file for the auto mode to take effect after another reboot.

Setting the operating mode to PEX

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the operating mode to PEX.	pex system-working-mode pex	By default, the device operates in auto mode. The device can automatically change to a PEX upon receiving LLDP packets from a parent device.
3. Save the running configuration.	save	N/A
4. Return to user view.	quit	N/A
5. Reboot the device.	reboot	N/A

Removing PEXs from an IRF 3.1 system

To temporarily remove a PEX from an IRF 3.1 system, disconnect the PEX links between the PEX and the parent fabric or power off the PEX.

To remove a PEX from an IRF 3.1 system and use it as an independent device, perform the following tasks after you log in to the PEX through the console port:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Change the PEX to switch mode.	pex system-working-mode switch	By default, the device operates in auto mode.
3. Save the running configuration.	save	The device will operate in the mode set in the startup configuration after a reboot if you do not save the running configuration.
4. Reboot the PEX for the mode change to take effect.	reboot	N/A

02-IRF Configuration Guide

Setting up an IRF fabric

IRF member roles

IRF member ID

IRF port

IRF physical interface

MAD

IRF domain ID

IRF split

IRF merge

Member priority

Detection

Failure recovery

Candidate IRF physical interfaces

IRF port binding restrictions

Selecting transceiver modules and cables

Assigning a member ID to each IRF member device

Specifying a priority for each member device

Connecting IRF physical interfaces

Configuring IRF link load sharing mode

Configuring the global load sharing mode

Configuring a port-specific load sharing mode

Enabling software auto-update for software image synchronization

Configuring BFD MAD that uses a VLAN interface

Configuring BFD MAD that uses a Layer 3 aggregate interface

Configuring BFD MAD that uses management Ethernet ports

Configuring ARP MAD that uses common Ethernet ports

Configuring ARP MAD that uses management Ethernet ports

Excluding an interface from the shutdown action upon detection of multi-active collision

Configuration restrictions and guidelines

Configuration procedure

Recovering an IRF fabric

Displaying and maintaining an IRF fabric

Network requirements

Configuration procedure

Network requirements

Configuration procedure

Network requirements

Configuration procedure

Network requirements

Configuration procedure

Setting up an IRF 3.1 system

One tier of PEXs

Multiple tiers of PEXs

IRF 3.1 roles

Cascade port

Upstream port

PEX group

Extended port

Layer 2 extended-link aggregate interface

Virtual chassis number and virtual slot number

Virtual slot number

Neighbor discovery

PE CSP connection establishment

PEX registration

PEX link maintenance

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