Contents

Basic IP forwarding commands· 1

display fib· 1

ip last-hop backup enable· 3

ip last-hop hold· 4

Load sharing commands· 5

ip load-sharing local-first enable· 5

ip load-sharing mode· 5

 

Basic IP forwarding commands

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

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 backup enable

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

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

Syntax

ip last-hop backup enable

undo ip last-hop backup enable

Default

Last hop backup is disabled.

Views

System view

Predefined user roles

network-admin

context-admin

context-operator

Usage guidelines

You can perform this task for information backup between IRF member devices. When receiving the first IP packet of a forward flow on an interface with last hop holding and session synchronization enabled, the IRF master device performs the following operations:

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 backward flow when the flow arrives at the master device or is forwarded through a subordinate device.

For more information about session synchronization, see Security Command Reference.

This feature is applicable only to IRF fabrics. Z-shaped traffic might be formed if packets are transparently sent from a subordinate device to the master device.

A device might have multiple packet processing cards on which service backup is enabled. This command enables the card that received the first IP packet of a forward flow on an interface with last hop holding enabled to perform the following operations:

1.     Saves the last hop information of the packet.

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

The last hop information can be used for guiding the backward flow when the flow arrives at the card or is forwarded through other cards.

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

Examples

# Enable last hop backup.

<Sysname> system-view

[Sysname] ip last-hop backup enable

Related commands

ip last-hop hold

session synchronization enable (Security Command Reference)

session flow-redirect enable (Security Command Reference)

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

Predefined user roles

network-admin

context-admin

Usage guidelines

Last hop holding implements symmetric routing. It tracks the last hop MAC address for the first incoming IP packet of a connection, and it sends the return packets to the hop that transmits the request.

Last hop holding is based on fast forwarding entries. If the MAC address of a last hop changes, 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

 

Load sharing commands

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

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

Parameters

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