Ethernet link aggregation, or simply link aggregation, combines multiple physical Ethernet ports into one logical link, called an aggregate link. Link aggregation delivers the following benefits:

· Increases bandwidth beyond the limits of any single link. In an aggregate link, traffic is distributed across the member ports.

· Improves link reliability. The member ports dynamically back up one another. When a member port fails, its traffic is automatically switched to other member ports.

As shown in Figure 1, Device A and Device B are connected by three physical Ethernet links. These physical Ethernet links are combined into an aggregate link, Link Aggregation 1. The bandwidth of this aggregate link is as high as the total bandwidth of these three physical Ethernet links. At the same time, the three Ethernet links back up one another.

Figure 1 Ethernet link aggregation

NOTE:

· The switch supports up to 240 aggregation groups.

· An aggregation group on the switch supports up to 12 Selected ports.

Basic concepts

Aggregation group, member port, aggregate interface

Ethernet link aggregation is implemented through link aggregation groups. An aggregation group is a group of Ethernet interfaces aggregated together, which are called member ports of the aggregation group. For each aggregation group, a logical interface, called an aggregate interface is created. To an upper layer entity that uses the link aggregation service, a link aggregation group looks like a single logical link and data traffic is transmitted through the aggregate interface.

There are two types of aggregate interfaces: Bridge-Aggregation (BAGG) interfaces, which are Layer 2 aggregate interfaces, and Route-Aggregation (RAGG) interfaces, which are Layer 3 aggregate interfaces. When an aggregate interface is created, an aggregation group of the same type and numbered the same is created automatically. For example, when you create interface Bridge-Aggregation 1, Layer 2 aggregation group 1 is created.

To a Layer 2 aggregation group, you can assign only Layer 2 Ethernet interfaces; to a Layer 3 aggregation group, only Layer 3 Ethernet interfaces.

NOTE:

· On a Layer 3 aggregate interface, you can create subinterfaces, which are called “Layer 3 aggregate subinterfaces.” These subinterfaces are logical interfaces that operate at the network layer. They can receive VLAN tagged packets for their Layer 3 aggregate interface.

· The rate of an aggregate interface equals the total rate of its member ports in selected state and its duplex mode is the same as that of the selected member ports. For more information about the states of member ports in an aggregation group, see “Aggregation states of member ports in an aggregation group.”

Aggregation states of member ports in an aggregation group

A member port in an aggregation group can be in either of the following two aggregation states:

· Selected—A Selected port can forward user traffic.

· Unselected—An Unselected port cannot forward user traffic.

Operational key

When aggregating ports, the system automatically assigns each port an operational key based on port information such as port rate and duplex mode. Any change to this information triggers a recalculation of this operational key.

In an aggregation group, all selected member ports are assigned the same operational key.

Configuration classes

Every configuration setting on a member port in a link aggregation group may affect the aggregation state of the port in the group more or less. They are divided into three configuration classes:

· Port attribute configurations, including port rate, duplex mode, and link status (up/down), which are the most basic port configurations.

· Class-two configurations, as described in Table 1. A member port can be placed in selected state only if it has the same class-two configurations as the aggregate interface.

Table 1 Class-two configurations

Item	Considerations
Port isolation	Whether the port has joined an isolation group, and the isolation group to which the port belongs
QinQ	QinQ enable state (enable/disable), TPID for VLAN tags, outer VLAN tags to be added, inner-to-outer VLAN priority mappings, inner-to-outer VLAN tag mappings, inner VLAN ID substitution mappings
VLAN	Permitted VLAN IDs, PVID, link type (trunk, hybrid, or access), IP subnet-based VLAN configuration, protocol-based VLAN configuration, VLAN tagging mode
MAC address learning	MAC address learning capability, MAC address learning limit, forwarding of frames with unknown destination MAC addresses after the MAC address learning limit is reached

NOTE:

· Class-two configurations made on an aggregate interface are automatically synchronized to all its member ports. These configurations are retained on the member ports even after the aggregate interface is removed.

· Any class-two configuration change may affect the aggregation state of link aggregation member ports and thus ongoing traffic. To make sure that you are aware of the risk, the system displays a warning message every time you attempt to change a class-two configuration setting on a member port.

· Class-one configurations, which are configurations that do not affect the aggregation state of the member port even if they are different from those on the aggregate interface. GVRP and MSTP settings are examples of class-one configurations.

Reference port

When setting the aggregation state of the ports in an aggregation group, the system automatically picks a member port as the reference. This port is called the reference port of the aggregation group. The port attribute and class-two configurations of every other member port are compared with those of the reference port.

LACP protocol

The IEEE 802.3ad Link Aggregation Control Protocol (LACP) enables dynamic aggregation of physical links. It uses link aggregation control protocol data units (LACPDUs) for exchanging aggregation information between LACP-enabled network devices.

1. LACP functions

Based on the fields carried in LACPDUs, the functions delivered by the IEEE 802.3ad LACP fall into basic LACP functions and extended LACP functions, as described in Table 2.

Table 2 Basic and extended LACP functions

Category	Description
Basic LACP functions	Implemented through the basic LACPDU fields including the system LACP priority, system MAC address, port aggregation priority, port number, and operational key. Each member port in a LACP-enabled aggregation group exchanges the above information with its peer. When a member port receives an LACPDU, it compares the received information with the information received on the other member ports. In this way the two systems reach an agreement on which ports should be placed in the selected state.
Extended LACP functions	Implemented by extending the LACPDU with new Type/Length/Value (TLV) fields. This is how the LACP multi-active detection (MAD) mechanism of the Intelligent Resilient Framework (IRF) feature is implemented. · If a switch supports both LACP extensions and IRF, it can participate in LACP MAD either as an IRF member switch or an intermediate switch. · If a switch supports LACP extensions but not IRF, it can participate in LACP MAD only as an intermediate switch.

Type	Description	Remarks
System LACP priority	Used by two peer devices (or systems) to determine which one is superior in link aggregation. In dynamic link aggregation, the system that has higher system LACP priority sets the selected state of member ports on its side first and then the system that has lower priority sets port state accordingly.	The smaller the priority value, the higher the priority.
Port aggregation priority	Determines the likelihood of a member port to be selected on a system. The higher port aggregation priority, the higher likelihood.

Link aggregation modes

There are two link aggregation modes: dynamic and static. Dynamic link aggregation uses LACP while static link aggregation does not. A link aggregation group operating in static mode is called a static link aggregation group, while a link aggregation group operating in dynamic mode is called a dynamic link aggregation group. Table 4 compares the two aggregation modes.

Table 4 A comparison between static and dynamic aggregation modes

Aggregation mode	LACP status on member ports	Pros	Cons
Static	Disabled	Aggregation is stable. The aggregation state of the member ports is not affected by their peers.	The member ports cannot change their aggregation state in consistent with their peers. The administrator needs to manually maintain link aggregations.
Dynamic	Enabled	The administrator does not need to maintain link aggregations. The peer systems maintain the aggregation state of the member ports automatically.	The aggregation state of member ports is easily affected by the network environment, which makes dynamic aggregation less stable.

In a dynamic link aggregation group:

· A Selected port can receive and send LACPDUs.

· An Unselected port can receive and send LACPDUs only if it is up and have the same class-two configurations as the aggregate interface.

Aggregating links in static mode

LACP is disabled on the member ports in a static aggregation group. The aggregation state of the member ports must be maintained manually.

Static link aggregation comprises:

· Selecting a reference port

· Setting the aggregation state of each member port

Selecting a reference port

The system selects a reference port from the member ports that are in the up state and have the same class-two configurations as the aggregate interface.

The candidate ports are sorted by aggregation priority, duplex, and speed in the following order:

· Lowest aggregation priority value

· Full duplex/high speed

· Full duplex/low speed

· Half duplex/high speed

· Half duplex/low speed

The one at the top is selected as the reference port. If two ports have the same aggregation priority, duplex mode, and speed, the one with the lower port number wins out.

Setting the aggregation state of each member port

After selecting the reference port, the static aggregation group sets the aggregation state of each member port as shown in Figure 2.

Figure 2 Setting the aggregation state of a member port in a static aggregation group

NOTE:

· Any port attribute or class-two configuration change on a member port may change the aggregation state and cause service interruption.

· A port that joins the static aggregation group after the Selected port limit has been reached will not be placed in the selected state even if it otherwise should be. This is can prevent ongoing traffic on the current Selected ports from being interrupted. You should avoid the situation, however, as it can cause the aggregation state of a port to change after a reboot.

Aggregating links in dynamic mode

LACP is automatically enabled on all member ports in a dynamic aggregation group. The protocol maintains the aggregation state of ports automatically.

Dynamic link aggregation comprises:

· Selecting a reference port

· Setting the aggregation state of each member port

Selecting a reference port

The local system (the actor) negotiates with the remote system (the partner) to select a reference port as follows:

1. Compare the system ID (comprising the system LACP priority and the system MAC address) of the actor with that of the partner. The system with the lower LACP priority value wins out. If they are the same, compare the system MAC addresses. The system with the lower MAC address wins out.

2. Compare the port IDs of the ports on the system with the smaller system ID. A port ID comprises a port aggregation priority and a port number. First compare the port aggregation priorities. The port with the lower aggregation priority value wins out. If two ports have the same aggregation priority, compare their port numbers. The port with the smaller port number wins out. Thus, the port with the lowest port ID is selected as the reference port.

Setting the aggregation state of each member port

After the reference port is selected, the system with the lower system ID sets the state of each member port in the dynamic aggregation group on its side as shown in Figure 3.

Figure 3 Setting the state of a member port in a dynamic aggregation group

Meanwhile, the system with the higher system ID, being aware of the aggregation state changes on the remote system, changes the aggregation state of its ports accordingly.

NOTE:

· A dynamic link aggregation group preferably sets full-duplex ports as the Selected ports, and will set one, and only one, half-duplex port as a Selected port when none of the full-duplex ports can be selected or only half-duplex ports exist in the group.

· Any member port attribute or class-two configuration change may affect the aggregation state of link aggregation member ports and ongoing traffic.

· In a dynamic aggregation group, when the aggregation state of a local port changes, the aggregation state of the peer port also changes accordingly.

· A port that joins a dynamic aggregation group after the Selected port limit has been reached is placed in the Selected state if it is more eligible for being selected than a current member port.

Load sharing criteria for link aggregation groups

In a link aggregation group, traffic may be load-shared across the selected member ports based on a set of criteria, depending on your configuration.

You can choose one of the following criteria or any combination for load sharing:

· MAC addresses

· IP addresses

· Service port numbers

· Ingress ports

· MPLS labels

Ethernet link aggregation configuration task list

Complete the following tasks to configure Ethernet link aggregation:

Task		Remarks
Configuring an aggregation group	Configuring a static aggregation group	Select either task
Configuring an aggregation group	Configuring a dynamic aggregation group	Select either task
Configuring an aggregate interface	Configuring the description of an aggregate interface/subinterface	Optional
	Configuring the MTU of a Layer 3 aggregate interface/subinterface	Optional
	Enabling link state trapping for an aggregate interface	Optional
	Limiting the number of Selected ports for an aggregation group	Optional
	Shutting down an aggregate interface	Optional
	Restoring the default settings for an aggregate interface	Optional
Configuring load sharing for link aggregation groups		Optional
Enabling link-aggregation traffic redirection		Optional

Configuring an aggregation group

You can choose to create a Layer 2 or Layer 3 link aggregation group depending on the ports to be aggregated:

· To aggregate Layer 2 Ethernet interfaces, create a Layer 2 link aggregation group;

· To aggregate Layer 3 Ethernet interfaces, create a Layer 3 link aggregation group.

Configuration guidelines

You cannot assign a port to a Layer 2 aggregation group if any of the features listed in Table 5 is configured on the port.

Table 5 Features incompatible with Layer 2 aggregation groups

Feature	Reference
RRPP	RRPP configuration in High Availability Configuration Guide
MAC authentication	MAC authentication configuration in Security Configuration Guide
IP source guard	IP source guard configuration in Security Configuration Guide
802.1X	802.1X configuration in Security Configuration Guide
Ports specified as source interfaces in portal-free rules	Portal configuration in Security Configuration Guide

You cannot assign a port to a Layer 3 aggregation group if any of the features listed in Table 6 is configured on the port.

Table 6 Interfaces that cannot be assigned to a Layer 3 aggregation group

Interface type	Reference
Interfaces configured with IP addresses	IP addressing configuration in Layer 3—IP Services Configuration Guide
VRRP	VRRP configuration in High Availability Configuration Guide
Portal	Portal in Security Configuration Guide

NOTE:

· If a port is used as a reflector port for port mirroring, do not assign it to an aggregation group. For more information about reflector ports, see Network Management and Monitoring Configuration Guide.

· Removing an aggregate interface also removes the corresponding aggregation group. At the same time, any member ports of the aggregation group leave the aggregation group.

· Do not configure any Layer 3 features, such as MPLS and VPN, on a port to be added to a Layer 3 aggregation group. Remove any Layer 3 feature configured on a port before adding it to a Layer 3 aggregation group.

· After adding a port to a Layer 3 aggregation group, configure Layer 3 features on the aggregate interface instead of on the member port. If you configure any Layer 3 feature mistakenly on a member port, remove the Layer 3 feature configuration from the member port and then run the shutdown and undo shutdown commands on the aggregate interface.

Configuring a static aggregation group

Configuring a Layer 2 static aggregation group

To configure a Layer 2 static aggregation group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Create a Layer 2 aggregate interface and enter Layer 2 aggregate interface view.	interface bridge-aggregation interface-number	When you create a Layer 2 aggregate interface, the system automatically creates a static aggregation group numbered the same.
3. Return to system view.	quit	N/A
4. Enter Layer 2 Ethernet interface view.	interface interface-type interface-number	Repeat these two steps to assign multiple Layer 2 Ethernet interfaces to the aggregation group.
5. Assign the Ethernet interface to the aggregation group.	port link-aggregation group number
6. Assign the port an aggregation priority.	link-aggregation port-priority port-priority	Optional. By default, the aggregation priority of a port is 32768. Changing the aggregation priority of a port may affect the aggregation state of the ports in the static aggregation group.

Configuring a Layer 3 static aggregation group

To configure a Layer 3 static aggregation group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Create a Layer 3 aggregate interface and enter the Layer 3 aggregate interface view.	interface route-aggregation interface-number	When you create a Layer 3 aggregate interface, the system automatically creates a Layer 3 static aggregation group numbered the same.
3. Return to system view.	quit	N/A
4. Enter Layer 3 Ethernet interface view.	interface interface-type interface-number	Repeat these two steps to assign multiple Layer 3 Ethernet interfaces to the aggregation group.
5. Assign the Ethernet interface to the aggregation group.	port link-aggregation group number
6. Assign the port an aggregation priority.	link-aggregation port-priority port-priority	Optional. By default, the aggregation priority of a port is 32768. Changing the aggregation priority of a port may affect the aggregation state of the ports in the static aggregation group.

Configuring a dynamic aggregation group

NOTE:

To guarantee a successful dynamic aggregation, make sure that the peer ports of the ports aggregated at one end are also aggregated. The two ends can automatically negotiate the aggregation state of each member port.

Configuring a Layer 2 dynamic aggregation group

To configure a Layer 2 dynamic aggregation group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the system LACP priority.	lacp system-priority system-priority	Optional. By default, the system LACP priority is 32768. Changing the system LACP priority may affect the aggregation state of the ports in dynamic aggregation groups.
3. Create a Layer 2 aggregate interface and enter the Layer 2 aggregate interface view.	interface bridge-aggregation interface-number	When you create a Layer 2 aggregate interface, the system automatically creates a Layer 2 static aggregation group numbered the same.
4. Configure the aggregation group to work in dynamic aggregation mode.	link-aggregation mode dynamic	By default, an aggregation group works in static aggregation mode.
5. Return to system view.	quit	N/A
6. Enter Layer 2 Ethernet interface view.	interface interface-type interface-number	Repeat these two steps to assign multiple Layer 2 Ethernet interfaces to the aggregation group.
7. Assign the Ethernet interface to the aggregation group.	port link-aggregation group number
8. Assign the interface an aggregation priority.	link-aggregation port-priority port-priority	Optional. By default, the aggregation priority of a port is 32768. Changing the aggregation priority of a port may affect the aggregation state of the ports in the dynamic aggregation group.
9. Set the LACP timeout interval on the port to the short timeout interval (1 second).	lacp period short	Optional. By default, the LACP timeout interval on a port is the long timeout interval (30 seconds).

Configuring a Layer 3 dynamic aggregation group

To configure a Layer 3 dynamic aggregation group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the system LACP priority.	lacp system-priority system-priority	Optional. By default, the system LACP priority is 32768. Changing the system LACP priority may affect the aggregation state of the ports in the dynamic aggregation group.
3. Create a Layer 3 aggregate interface and enter the Layer 3 aggregate interface view.	interface route-aggregation interface-number	When you create a Layer 3 aggregate interface, the system automatically creates a Layer 3 static aggregation group numbered the same.
4. Configure the aggregation group to work in dynamic aggregation mode.	link-aggregation mode dynamic	By default, an aggregation group works in static aggregation mode.
5. Return to system view.	quit	N/A
6. Enter Layer 3 Ethernet interface view.	interface interface-type interface-number	Repeat these two steps to assign multiple Layer 3 Ethernet interfaces to the aggregation group.
7. Assign the Ethernet interface to the aggregation group.	port link-aggregation group number
8. Assign the port an aggregation priority.	lacp port-priority port-priority	Optional. By default, the aggregation priority of a port is 32768. Changing the aggregation priority of a port may affect the aggregation state of ports in the dynamic aggregation group.
9. Set the LACP timeout interval on the port to the short timeout interval (1 second).	lacp period short	Optional. By default, the LACP timeout interval on a port is the long timeout interval (30 seconds).

Configuring an aggregate interface

NOTE:

In addition to the configurations in this section, most of the configurations that can be performed on Layer 2 or Layer 3 Ethernet interfaces can also be performed on Layer 2 or Layer 3 aggregate interfaces.

Configuring the description of an aggregate interface/subinterface

You can configure the description of an aggregate interface for administration purposes such as describing the purpose of the interface.

To configure the description of an aggregate interface/subinterface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface/subinterface view: interface route-aggregation { interface-number \| interface-number.subnumber }	Use either command.
3. Configure the description of the aggregate interface/subinterface.	description text	Optional. By default, the description of an interface is interface-name Interface, such as Bridge-Aggregation1 Interface.

Configuring the MTU of a Layer 3 aggregate interface/subinterface

Maximum transmission unit (MTU) of an interface affects IP packets fragmentation and reassembly on the interface.

To change the MTU of a Layer 3 aggregate interface/subinterface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter Layer 3 aggregate interface/subinterface view.	interface route-aggregation { interface-number \| interface-number.subnumber }	N/A
3. Configure the MTU of the interface/subinterface.	mtu size	Optional. The default setting is 1500 bytes.

Enabling link state trapping for an aggregate interface

You can configure an aggregate interface to generate linkUp trap messages when its link goes up and linkDown trap messages when its link goes down. For more information, see Network Management and Monitoring Configuration Guide.

To enable link state trapping on an aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enable the trap function globally.	snmp-agent trap enable [ standard [ linkdown \| linkup ] * ]	Optional. By default, link state trapping is enabled globally and on all interfaces.
3. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface/subinterface view: interface route-aggregation { interface-number \| interface-number.subnumber }	Use either command.
4. Enable link state trapping for the aggregate interface.	enable snmp trap updown	Optional. By default, link state trapping is enabled for the aggregate interface.

Limiting the number of Selected ports for an aggregation group

The bandwidth of an aggregate link increases along with the number of selected member ports. To avoid congestion caused by insufficient Selected ports on an aggregate link, you can set the minimum number of Selected ports required for bringing up the specific aggregate interface.

This minimum threshold setting affects the aggregation state of both aggregation member ports and the aggregate interface:

· All member ports change to the Unselected state and the link of the aggregate interface goes down, when the number of member ports eligible for being selected is smaller than the minimum threshold.

· When the minimum threshold is reached, the eligible member ports change to the Selected state, and the link of the aggregate interface goes up.

By default, the maximum number of Selected ports allowed in an aggregation group is not restricted. After you manually configure the maximum number of Selected ports in an aggregation group, the maximum number of Selected ports allowed in the aggregation group is the limit you set.

You can configure redundancy between two ports using the following guideline: Assign two ports to an aggregation group, and configure the maximum number of Selected ports allowed in the aggregation group as 1. In this way, only one Selected port is allowed in the aggregation group at any point in time, while the Unselected port serves as a backup port.

To limit the number of Selected ports for an aggregation group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. 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	Use either command.
3. Set the minimum number of Selected ports for the aggregation group.	link-aggregation selected-port minimum number	By default, the minimum number of Selected ports is not specified.
4. Set the maximum number of Selected ports for the aggregation group.	link-aggregation selected-port maximum number	By default, the maximum number of Selected ports is not specified.

CAUTION:

· If you set this minimum threshold for a static aggregation group, you must also make the same setting for its peer aggregation group to guarantee correct aggregation.

· Configuring the minimum number of Selected ports required to bring up an aggregation group may cause all the member ports in the aggregation group to become unselected.

· Make sure that the minimum number of Selected ports required to bring up an aggregation group is the same on both ends.

· Configuring the maximum number of Selected ports in an aggregation group may cause some of the selected member ports in the aggregation group to become unselected.

· If you configure both the maximum number of Selected ports allowed in the aggregation group and the minimum number of Selected ports in the aggregation group, make sure that the former is no smaller than the latter.

Shutting down an aggregate interface

Shutting down or bringing up an aggregate interface affects the aggregation state and link state of ports in the corresponding aggregation group in the following ways:

· When an aggregate interface is shut down, all Selected ports in the corresponding aggregation group become unselected and their link state becomes down.

· When an aggregate interface is brought up, the aggregation state of ports in the corresponding aggregation group is recalculated and their link state becomes up.

To bring up an aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface or subinterface view: interface route-aggregation { interface-number \| interface-number.subnumber }	Use either command.
3. Shut down the aggregate interface.	shutdown	By default, aggregate interfaces are up.

NOTE:

Shutting down a Layer 3 aggregate subinterface does not affect any aggregation group, because Layer 3 aggregate subinterfaces are not associated with any aggregation groups.

Restoring the default settings for an aggregate interface

To restore the default settings for an aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface or subinterface view: interface route-aggregation { interface-number \| interface-number.subnumber }	Use either command.
3. Restore the default settings for the aggregate interface or subinterface.	default	N/A

Configuring load sharing for link aggregation groups

You can determine how traffic is load-shared in a link aggregation group by configuring load sharing criteria. The criteria can be MPLS labels, service port numbers, IP addresses, MAC addresses, or receiving ports of packets, or any combination of them. The system uses the hash algorithm to calculate the load sharing scheme for link aggregation groups based on the load sharing criteria you configured.

To configure load sharing for link aggregation groups:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Configure the load sharing criteria for link aggregation groups.	link-aggregation load-sharing mode { destination-ip \| destination-mac \| destination-port \| ingress-port \| \| mpls-label1 \| mpls-label2 \| mpls-label3 \| source-ip \| source-mac \| source-port } *	Optional. By default, load sharing is enabled for link aggregation groups. The setting you make by using this command affects all load-sharing link aggregation groups.

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Configure the load sharing criteria for link aggregation groups.

link-aggregation load-sharing mode { destination-ip | destination-mac | destination-port | ingress-port | | mpls-label1 | mpls-label2 | mpls-label3 | source-ip | source-mac | source-port } *

Optional.

By default, load sharing is enabled for link aggregation groups.

The setting you make by using this command affects all load-sharing link aggregation groups.

Enabling link-aggregation traffic redirection

The link-aggregation traffic redirection function is available on switches or IRF member switches. It can redirect traffic between cards or IRF member switches for a cross-card or cross-switch link aggregation group. With this function, you can prevent traffic interruption when rebooting a card or IRF member switch that contains link aggregation member ports. For more information about IRF, see IRF Configuration Guide.

To enable link-aggregation traffic redirection:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enable link-aggregation traffic redirection.	link-aggregation lacp traffic-redirect-notification enable	Optional. By default, link-aggregation traffic redirection is disabled.

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Enable link-aggregation traffic redirection.

link-aggregation lacp traffic-redirect-notification enable

Optional.

By default, link-aggregation traffic redirection is disabled.

CAUTION:

· Link-aggregation traffic redirection applies to dynamic link aggregation groups only.

· To prevent traffic interruption, you must enable link-aggregation traffic redirection on switches at both ends of the aggregate link.

· To prevent packet loss that might occur at a reboot, do not enable MSTP and link-aggregation traffic redirection at the same time.

Displaying and maintaining Ethernet link aggregation

Task	Command	Remarks
Display information for an aggregate interface or multiple aggregate interfaces.	display interface [ bridge-aggregation \| route-aggregation ] [ brief [ down ] ] [ \| { begin \| exclude \| include } regular-expression ] display interface { bridge-aggregation \| route-aggregation } interface-number [ brief ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display the local system ID.	display lacp system-id [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display detailed link aggregation information for link aggregation member ports.	display link-aggregation member-port [ interface-list ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display the summary of all aggregation groups.	display link-aggregation summary [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display detailed information about a specific or all aggregation groups.	display link-aggregation verbose [ { bridge-aggregation \| route-aggregation } [ interface-number ] ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display link-aggregation load sharing criteria.	display link-aggregation load-sharing mode [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Clear LACP statistics for a specific or all link aggregation member ports.	reset lacp statistics [ interface interface-list ]	Available in user view
Clear statistics for a specific or all aggregate interfaces.	reset counters interface [ { bridge-aggregation \| route-aggregation } [ interface-number ] ]	Available in user view

Ethernet link aggregation configuration examples

NOTE:

· In an aggregation group, only ports that have the same port attributes and class-two configurations (see “Configuration classes”) as the reference port (see “Reference port”) can operate as Selected ports. Make sure that all member ports have the same port attributes and class-two configurations as the reference port. The other settings only need to be configured on the aggregate interface, not on the member ports.

· By default, Ethernet interfaces, VLAN interfaces, and aggregate interfaces are in the down state. Before configuring these interfaces, use the undo shutdown command to bring them up.

Layer 2 static aggregation configuration example

Network requirements

As shown in Figure 4:

· Configure a Layer 2 static link aggregation group on Device A and Device B respectively, and enable VLAN 10 at one end of the aggregate link to communicate with VLAN 10 at the other end, and VLAN 20 at one end to communicate with VLAN 20 at the other end.

· Enable traffic to be load-shared across aggregation group member ports based on source and destination MAC addresses.

Figure 4 Network diagram

Configuration procedure

1. Configure Device A:

# Create VLAN 10, and assign port GigabitEthernet 4/0/4 to VLAN 10.

<DeviceA> system-view

[DeviceA] vlan 10

[DeviceA-vlan10] port gigabitethernet 4/0/4

[DeviceA-vlan10] quit

# Create VLAN 20, and assign port GigabitEthernet 4/0/5 to VLAN 20.

[DeviceA] vlan 20

[DeviceA-vlan20] port gigabitethernet 4/0/5

[DeviceA-vlan20] quit

# Create Layer 2 aggregate interface Bridge-Aggregation 1.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] quit

# Assign ports GigabitEthernet 4/0/1 through GigabitEthernet 4/0/3 to link aggregation group 1.

[DeviceA] interface gigabitethernet 4/0/1

[DeviceA-GigabitEthernet4/0/1] port link-aggregation group 1

[DeviceA-GigabitEthernet4/0/1] quit

[DeviceA] interface gigabitethernet 4/0/2

[DeviceA-GigabitEthernet4/0/2] port link-aggregation group 1

[DeviceA-GigabitEthernet4/0/2] quit

[DeviceA] interface gigabitethernet 4/0/3

[DeviceA-GigabitEthernet4/0/3] port link-aggregation group 1

[DeviceA-GigabitEthernet4/0/3] quit

# Configure Layer 2 aggregate interface Bridge-Aggregation 1 as a trunk port and assign it to VLANs 10 and 20.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] port link-type trunk

[DeviceA-Bridge-Aggregation1] port trunk permit vlan 10 20

Please wait... Done.

[DeviceA-Bridge-Aggregation1] quit

# Configure Device A to use the source and destination MAC addresses of packets as the global link-aggregation load sharing criteria.

[DeviceA] link-aggregation load-sharing mode source-mac destination-mac

2. Configure Device B:

Configure Device B using the same instructions that you used to configure Device A.

3. Verify the configurations:

# Display summary information about all aggregation groups on Device A.

[DeviceA] display link-aggregation summary

Aggregation Interface Type:

BAGG -- Bridge-Aggregation, RAGG -- Route-Aggregation

Aggregation Mode: S -- Static, D -- Dynamic

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Actor System ID: 0x8000, 000f-e2ff-0001

AGG AGG Partner ID Select Unselect Share

Interface Mode Ports Ports Type

-------------------------------------------------------------------------------

BAGG1 S none 3 0 Shar

The output shows that link aggregation group 1 is a load shared Layer 2 static aggregation group and it contains three Selected ports.

# Display the global link-aggregation load sharing criteria on Device A.

[DeviceA] display link-aggregation load-sharing mode

Link-Aggregation Load-Sharing Mode:

destination-mac address, source-mac address

The output shows that all link aggregation groups created on the device perform load sharing based on source and destination MAC addresses.

Layer 2 dynamic aggregation configuration example

Network requirements

As shown in Figure 5:

· Configure a Layer 2 dynamic link aggregation group on Device A and Device B respectively, enable VLAN 10 at one end of the aggregate link to communicate with VLAN 10 at the other end, and VLAN 20 at one end to communicate with VLAN 20 at the other end.

· Enable traffic to be load-shared across aggregation group member ports based on source and destination MAC addresses.

Figure 5 Network diagram

Configuration procedure

1. Configure Device A:

# Create VLAN 10, and assign the port GigabitEthernet 4/0/4 to VLAN 10.

<DeviceA> system-view

[DeviceA] vlan 10

[DeviceA-vlan10] port gigabitethernet 4/0/4

[DeviceA-vlan10] quit

# Create VLAN 20, and assign the port GigabitEthernet 4/0/5 to VLAN 20.

[DeviceA] vlan 20

[DeviceA-vlan20] port gigabitethernet 4/0/5

[DeviceA-vlan20] quit

# Create Layer 2 aggregate interface Bridge-Aggregation 1, and configure the link aggregation mode as dynamic.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] link-aggregation mode dynamic

# Assign ports GigabitEthernet 4/0/1 through GigabitEthernet 4/0/3 to link aggregation group 1 one at a time.

[DeviceA] interface gigabitethernet 4/0/1

[DeviceA-GigabitEthernet4/0/1] port link-aggregation group 1

[DeviceA-GigabitEthernet4/0/1] quit

[DeviceA] interface gigabitethernet 4/0/2

[DeviceA-GigabitEthernet4/0/2] port link-aggregation group 1

[DeviceA-GigabitEthernet4/0/2] quit

[DeviceA] interface gigabitethernet 4/0/3

[DeviceA-GigabitEthernet4/0/3] port link-aggregation group 1

[DeviceA-GigabitEthernet4/0/3] quit

# Configure Layer 2 aggregate interface Bridge-Aggregation 1 as a trunk port and assign it to VLANs 10 and 20.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] port link-type trunk

[DeviceA-Bridge-Aggregation1] port trunk permit vlan 10 20

Please wait... Done.

[DeviceA-Bridge-Aggregation1] quit

# Configure the device to use the source and destination MAC addresses of packets as the global link-aggregation load sharing criteria.

[DeviceA] link-aggregation load-sharing mode source-mac destination-mac

2. Configure Device B:

Configure Device B using the same instructions that you used to configure Device A.

3. Verify the configurations:

# Display summary information about all aggregation groups on Device A.

[DeviceA] display link-aggregation summary

Aggregation Interface Type:

BAGG -- Bridge-Aggregation, RAGG -- Route-Aggregation

Aggregation Mode: S -- Static, D -- Dynamic

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Actor System ID: 0x8000, 000f-e2ff-0001

AGG AGG Partner ID Select Unselect Share

Interface Mode Ports Ports Type

-------------------------------------------------------------------------------

BAGG1 D 0x8000, 000f-e2ff-0002 3 0 Shar

The output shows that link aggregation group 1 is a load shared Layer 2 dynamic aggregation group and it contains three Selected ports.

# Display the global link-aggregation load sharing criteria on Device A.

[DeviceA] display link-aggregation load-sharing mode

Link-Aggregation Load-Sharing Mode:

destination-mac address, source-mac address

The output shows that all link aggregation groups created on the device perform load sharing based on source and destination MAC addresses.

Layer 3 static aggregation configuration example

Network requirements

As shown in Figure 6:

· Configure a Layer 3 static link aggregation group on Device A and Device B respectively and configure IP addresses and subnet masks for the corresponding Layer 3 aggregate interfaces.

· Enable traffic to be load-shared across aggregation group member ports based on source and destination IP addresses.

Figure 6 Network diagram

Configuration procedure

1. Configure Device A:

# Create Layer 3 aggregate interface Route-Aggregation 1, and configure an IP address and subnet mask for the aggregate interface.

<DeviceA> system-view

[DeviceA] interface route-aggregation 1

[DeviceA-Route-Aggregation1] ip address 192.168.1.1 24

[DeviceA-Route-Aggregation1] quit

# Assign Layer 3 Ethernet interfaces GigabitEthernet 3/0/1 through GigabitEthernet 3/0/3 to aggregation group 1.

[DeviceA] interface Gigabitethernet 3/0/1

[DeviceA-Gigabitethernet3/0/1] port link-aggregation group 1

[DeviceA-Gigabitethernet3/0/1] quit

[DeviceA] interface Gigabitethernet 3/0/2

[DeviceA-Gigabitethernet3/0/2] port link-aggregation group 1

[DeviceA-Gigabitethernet3/0/2] quit

[DeviceA] interface Gigabitethernet 3/0/3

[DeviceA-Gigabitethernet3/0/3] port link-aggregation group 1

[DeviceA-Gigabitethernet3/0/3] quit

# Configure the global link-aggregation load sharing criteria as the source and destination IP addresses of packets.

[DeviceA] link-aggregation load-sharing mode source-ip destination-ip

2. Configure Device B:

Configure Device B as you configured Device A.

3. Verify the configurations:

# Display the summary information about all aggregation groups on Device A.

[DeviceA] display link-aggregation summary

Aggregation Interface Type:

BAGG -- Bridge-Aggregation, RAGG -- Route-Aggregation

Aggregation Mode: S -- Static, D -- Dynamic

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Actor System ID: 0x8000, 000f-e2ff-0001

AGG AGG Partner ID Select Unselect Share

Interface Mode Ports Ports Type

-------------------------------------------------------------------------------

RAGG1 S none 3 0 Shar

The output above shows that link aggregation group 1 is a load-sharing-capable Layer 3 static aggregation group that contains three Selected ports.

# Display the global link-aggregation load sharing criteria on Device A.

[DeviceA] display link-aggregation load-sharing mode

Link-Aggregation Load-Sharing Mode:

destination-ip address, source-ip address

The output above shows that the global link-aggregation load sharing criteria are the source and destination IP addresses of packets.

Layer 3 dynamic aggregation configuration example

Network requirements

As shown in Figure 7:

· Configure a Layer 3 dynamic link aggregation group on Device A and Device B respectively and configure IP addresses and subnet masks for the corresponding Layer 3 aggregate interfaces.

· Enable traffic to be load-shared across aggregation group member ports based on source and destination IP addresses.

Figure 7 Network diagram

Configuration procedure

1. Configure Device A:

# Create Layer 3 aggregate interface Route-Aggregation 1, configure the link aggregation mode as dynamic, and configure an IP address and subnet mask for the aggregate interface.

<DeviceA> system-view

[DeviceA] interface route-aggregation 1

[DeviceA-Route-Aggregation1] link-aggregation mode dynamic

[DeviceA-Route-Aggregation1] ip address 192.168.1.1 24

[DeviceA-Route-Aggregation1] quit

# Assign Layer 3 Ethernet interfaces GigabitEthernet 3/0/1 through GigabitEthernet 3/0/3 to aggregation group 1.

[DeviceA] interface Gigabitethernet 3/0/1

[DeviceA-Gigabitethernet3/0/1] port link-aggregation group 1

[DeviceA-Gigabitethernet3/0/1] quit

[DeviceA] interface Gigabitethernet 3/0/2

[DeviceA-Gigabitethernet3/0/2] port link-aggregation group 1

[DeviceA-Gigabitethernet3/0/2] quit

[DeviceA] interface Gigabitethernet 3/0/3

[DeviceA-Gigabitethernet3/0/3] port link-aggregation group 1

[DeviceA-Gigabitethernet3/0/3] quit

# Configure to use the source and destination IP addresses of packets as the global link-aggregation load sharing criteria.

[DeviceA] link-aggregation load-sharing mode source-ip destination-ip

2. Configure Device B:

Configure Device B as you configured Device A.

3. Verify the configurations:

# Display the summary information about all aggregation groups on Device A.

[DeviceA] display link-aggregation summary

Aggregation Interface Type:

BAGG -- Bridge-Aggregation, RAGG -- Route-Aggregation

Aggregation Mode: S -- Static, D -- Dynamic

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Actor System ID: 0x8000, 000f-e2ff-0001

AGG AGG Partner ID Select Unselect Share

Interface Mode Ports Ports Type

-------------------------------------------------------------------------------

RAGG1 D 0x8000, 000f-e2ff-0002 3 0 Shar

The output shows that link aggregation group 1 is a load-shared Layer 3 dynamic aggregation group and it contains three Selected ports.

# Display the global link-aggregation load sharing criteria on Device A.

[DeviceA] display link-aggregation load-sharing mode

Link-Aggregation Load-Sharing Mode:

destination-ip address, source-ip address

The output shows that the global link-aggregation load sharing criteria are the source and destination IP addresses of packets.

04-Layer 2 - LAN Switching Configuration Guide

Aggregation group, member port, aggregate interface

Operational key

Configuration classes

LACP protocol

Link aggregation modes

Ethernet link aggregation configuration task list

Configuring a Layer 2 dynamic aggregation group

Configuring the description of an aggregate interface/subinterface

Configuring the MTU of a Layer 3 aggregate interface/subinterface

Network requirements

Configuration procedure

Network requirements

Configuration procedure

Network requirements

Configuration procedure

Network requirements

Configuration procedure

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