Contents

Basic IP forwarding commands· 1

display fib· 1

ip last-hop hold· 3

last-hop backup enable· 4

Load sharing commands· 6

bandwidth-based-sharing· 6

ip load-sharing local-first enable· 6

ip load-sharing mode· 7

 

Basic IP forwarding commands

Non-default vSystems do not support some of the basic IP forwarding commands. For information about vSystem support for a command, see the usage guidelines on that command. For information about vSystem, see Virtual Technologies Configuration Guide.

display fib

Use display fib to display FIB entries.

Syntax

display fib [ vpn-instance vpn-instance-name ] [ ip-address [ mask | mask-length ] ]

Views

Any view

Predefined user roles

network-admin

network-operator

context-admin

context-operator

vsys-admin

vsys-operator

Parameters

vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance by its name, a case-sensitive string of 1 to 31 characters. To display the FIB entries for the public network, do not specify any VPN instance.

ip-address: Displays the FIB entry that matches the specified destination IP address.

mask: Specifies the mask for the IP address.

mask-length: Specifies the mask length for the IP address. The value range is 0 to 32.

Usage guidelines

If you specify an IP address without a mask or mask length, this command displays the longest matching FIB entry.

If you specify an IP address and a mask or mask length, this command displays the exactly matching FIB entry.

Examples

# Display all FIB entries of the public network.

<Sysname> display fib

 

Destination count: 5 FIB entry count: 5

 

Flag:

  U:Useable   G:Gateway   H:Host   B:Blackhole   D:Dynamic   S:Static

  R:Relay     F:FRR

 

Destination/Mask   Nexthop         Flag     OutInterface/Token       Label

0.0.0.0/32         127.0.0.1       UH       InLoop0                  Null

192.168.100.0/24   192.168.100.103 U        MGE1/0/0/0               Null

127.0.0.0/8        127.0.0.1       U        InLoop0                  Null

127.0.0.0/32       127.0.0.1       UH       InLoop0                  Null

127.0.0.1/32       127.0.0.1       UH       InLoop0                  Null

# Display the FIB entries for VPN vpn1.

<Sysname> display fib vpn-instance vpn1

Destination count: 6 FIB entry count: 6

 

Flag:

  U:Useable   G:Gateway   H:Host   B:Blackhole   D:Dynamic   S:Static

  R:Relay     F:FRR

 

Destination/Mask   Nexthop         Flag     OutInterface/Token      Label

0.0.0.0/32         127.0.0.1       UH       InLoop0                  Null

20.20.20.0/24      20.20.20.25     U        MGE1/0/0/0                Null

20.20.20.0/32      20.20.20.25     UBH      MGE1/0/0/0                Null

20.20.20.25/32     127.0.0.1       UH       InLoop0                  Null

20.20.20.25/32     20.20.20.25     H        MGE1/0/0/0                Null

20.20.20.255/32    20.20.20.25     UBH      MGE1/0/0/0                Null

# Display the FIB entries matching the destination IP address 10.2.1.1.

<Sysname> display fib 10.2.1.1

 

Destination count: 1 FIB entry count: 1

 

Flag:

  U:Useable   G:Gateway   H:Host   B:Blackhole   D:Dynamic   S:Static

  R:Relay     F:FRR

 

Destination/Mask   Nexthop         Flag     OutInterface/Token       Label

10.2.1.1/32        127.0.0.1       UH       InLoop0                  Null

Table 1 Command output

Field	Description
Destination count	Total number of destination addresses.
FIB entry count	Total number of FIB entries.
Destination/Mask	Destination address and the mask length.
Nexthop	Next hop address.
Flag	Flags of routes: ·     U—Usable route. ·     G—Gateway route. ·     H—Host route. ·     B—Blackhole route. ·     D—Dynamic route. ·     S—Static route. ·     R—Relay route. ·     F—Fast reroute.
OutInterface/Token	Output interface/LSP index number.
Label	Inner label.

 

ip last-hop hold

Use ip last-hop hold to enable last hop holding.

Use undo ip last-hop hold to disable last hop holding.

Syntax

ip last-hop hold

undo ip last-hop hold

Default

Last hop holding is disabled.

Views

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Dialer interface view

Predefined user roles

network-admin

context-admin

vsys-admin

Usage guidelines

Last hop holding implements symmetric routing.

When the interface enabled with this feature receives the first IP packet of a forward flow, this feature implements the following operations:

·     Obtains the forward flow information and last hop information of the packet.

·     Based on the information, creates a fast forwarding entry for the reverse flow.

When packets of the reverse flow arrive at the device, the device forwards those packets based on the entry.

Last hop holding is based on fast forwarding entries. If the MAC address of a last hop changes on an Ethernet link, this feature can function correctly only after the fast forwarding entry is updated for the MAC address.

Examples

# Enable the last hop holding feature.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] ip last-hop hold

last-hop backup enable

Use last-hop backup enable to enable last hop backup.

Use undo last-hop backup enable to disable last hop backup.

Syntax

last-hop backup enable

undo last-hop backup enable

Default

Last hop backup is enabled.

Views

System view

Predefined user roles

network-admin

context-admin

vsys-admin

Usage guidelines

This feature enables the system to transmit the forward flow and reverse flow between the local device and a peer device over the same path.

In an IRF fabric enabled with this feature, the IRF master device performs the following operations when receiving the first IP packet of a forward flow on an interface enabled with last hop holding:

1.     Saves the last hop information of the packet.

2.     Synchronizes the last hop information to subordinate devices in the IRF fabric.

The last hop information can be used for guiding the reverse flow when the flow arrives at the master device or is forwarded through a subordinate device.

For this feature to takes effect, you must also enable last hop holding on the master device in the IRF fabric.

This command takes effect only when the session synchronization is enabled by using the session synchronization enable command. For more information about the session synchronization enable command, see Security Command Reference.

This feature is also applicable to multi-module devices enabled with service backup. If this feature is enabled on such a device, a device module performs the following operations when receiving the first IP packet of a forward flow on an interface enabled with last hop holding:

1.     Saves the last hop information of the packet.

2.     Synchronizes the last hop information to other modules in the device.

The last hop information can be used for guiding the backward flow when the flow arrives at one of these modules.

For this feature to take effect on a multi-module device, you must also enable session flow redirection by using the session flow-redirect enable command. For more information about the session flow-redirect enable command, see Security Command Reference.

Examples

# Disable last hop backup.

<Sysname> system-view

[Sysname] undo ip last-hop backup enable

Related commands

ip last-hop hold

session synchronization enable (Security Command Reference)

session flow-redirect enable (Security Command Reference)

 

Load sharing commands

bandwidth-based-sharing

Use bandwidth-based-sharing to enable IPv4 load sharing based on bandwidth.

Use undo bandwidth-based-sharing to disable IPv4 load sharing based on bandwidth.

Syntax

bandwidth-based-sharing

undo bandwidth-based-sharing

Default

The IPv4 load sharing based on bandwidth is disabled.

Views

System view

Predefined user roles

network-admin

context-admin

vsys-admin

Usage guidelines

Non-default vSystems do not support this command.

This feature load shares flow traffic among multiple output interfaces based on their load percentages. The device calculates the load percentage for each output interface in terms of their expected bandwidths.

Devices that run load sharing protocols, such as Locator/ID Separation Protocol (LISP), implement load sharing based on the ratios defined by these protocols.

Examples

# Enable IPv4 load sharing based on bandwidth.

<Sysname> system-view

[Sysname] bandwidth-based-sharing

ip load-sharing local-first enable

Use ip load-sharing local-first enable to enable local-first load sharing.

Use undo ip load-sharing local-first enable to disable local-first load sharing.

Syntax

ip load-sharing local-first enable

undo ip load-sharing local-first enable

Default

Local-first load sharing is disabled.

Views

System view

Predefined user roles

network-admin

context-admin

vsys-admin

Usage guidelines

Local-first load sharing takes effect only on an IRF fabric.

Examples

# Enable local-first load sharing.

<Sysname> system-view

[Sysname] ip load-sharing local-first enable

ip load-sharing mode

Use ip load-sharing mode to configure the load sharing mode.

Use undo ip load-sharing mode to restore the default.

Syntax

In standalone mode:

ip load-sharing mode { per-flow [ dest-ip | dest-port | ip-pro | src-ip | src-port ] * | per-packet } { global | slot slot-number [ cpu cpu-number ] }

undo ip load-sharing mode { global | slot slot-number [ cpu cpu-number ] }

In IRF mode:

ip load-sharing mode { per-flow [ dest-ip | dest-port | ip-pro | src-ip | src-port ] * | per-packet } { chassis chassis-number slot slot-number [ cpu cpu-number ] | global }

undo ip load-sharing mode { chassis chassis-number slot slot-number [ cpu cpu-number ] | global }

Default

The device performs per-flow load sharing.

Views

System view

Predefined user roles

network-admin

context-admin

vsys-admin

Parameters

algorithm-switch: Specifies algorithm 1 for per-flow load sharing.

per-flow: Implements per-flow load sharing.

dest-ip: Identifies flows by destination IP address.

dest-port: Identifies flows by destination port.

ip-pro: Identifies flows by protocol number.

src-ip: Identifies flows by source IP address.

src-port: Identifies flows by source port.

global: Configures the load sharing mode globally.

per-packet: Implements per-packet load sharing.

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command configures the load sharing mode for all cards. (In standalone mode.)

chassis chassis-number slot slot-number: Specifies a card on an IRF member device. The chassis-number argument represents the member ID of the IRF member device. The slot-number argument represents the slot number of the card. If you do not specify a card, this command configures the load sharing mode for all cards. (In IRF mode.)

cpu cpu-number: Specifies a CPU by its number. This option is available only if multiple CPUs are available on the specified slot.

Usage guidelines

The per-packet load sharing mode does not take effect in fast forwarding.

Examples

# Configure per-flow load sharing for slot 1.

<Sysname> system-view

[Sysname] ip load-sharing mode per-flow chassis 1 slot 1