Contents

Basic IP forwarding commands· 1

display fib· 1

ip forwarding-table save· 3

snmp-agent trap enable fib· 3

snmp-agent trap enable ip-forwarding· 4

 

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

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 FIB entries for topology mt.

<Sysname> display fib topology mt

 

Destination count: 8 FIB entry count: 8

 

Flag:

  U:Usable   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

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

127.255.255.255/32 127.0.0.1       UH       InLoop0                  Null

224.0.0.0/4        0.0.0.0         UB       NULL0                    Null

224.0.0.0/24       0.0.0.0         UB       NULL0                    Null

255.255.255.255/32 127.0.0.1       UH       InLoop0                  Null

# Display all FIB entries of the public network.

<Sysname> display fib

 

Destination count: 5 FIB entry count: 5

 

Flag:

  U:Usable   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

1.1.1.0/24         192.168.126.1   USGF     M-GE0/0/0                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:Usable   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        M-GE0/0/0                Null

20.20.20.0/32      20.20.20.25     UBH      M-GE0/0/0                Null

20.20.20.25/32     127.0.0.1       UH       InLoop0                  Null

20.20.20.25/32     20.20.20.25     H        M-GE0/0/0                Null

20.20.20.255/32    20.20.20.25     UBH      M-GE0/0/0                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:Usable   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 forwarding-table save

Use ip forwarding-table save to save the IP forwarding entries to a file.

Syntax

ip forwarding-table save filename filename

Views

Any view

Predefined user roles

network-admin

Parameters

filename filename: Specifies the name of a file, a string of 1 to 255 characters. For information about the filename argument, see file system management in Fundamentals Configuration Guide.

Usage guidelines

The command automatically creates the file if you specify a nonexistent file. If the file already exists, this command overwrites the file content.

To automatically save the IP forwarding entries periodically, configure a schedule for the device to automatically run the ip forwarding-table save command. For information about scheduling a task, see Fundamentals Configuration Guide.

Examples

# Save the IP forwarding entries to the fib.txt file.

<Sysname> ip forwarding-table save filename fib.txt

snmp-agent trap enable fib

Use snmp-agent trap enable fib to enable SNMP notifications for FIB events.

Use undo snmp-agent trap enable fib to disable SNMP notifications for FIB events.

Syntax

snmp-agent trap enable fib [ deliver-failed | entry-consistency | entry-limit ] *

undo snmp-agent trap enable fib [ deliver-failed | entry-consistency | entry-limit ] *

Default

SNMP notifications for FIB events are enabled.

Views

System view

Predefined user roles

network-admin

Parameters

deliver-failed: Specifies notifications to be sent when FIB entry deployment to the hardware fails.

entry-consistency: Specifies notifications to be sent when the FIB software and hardware entries are inconsistent.

entry-limit: Specifies notifications to be sent when the number of FIB entries exceeds the upper limit.

Usage guidelines

This feature enables the FIB module to generate SNMP notifications for critical FIB events. The SNMP notifications are sent to the SNMP module.

You can enable specific SNMP notifications for FIB events as needed. If you do not specify any SNMP notification types, the command enables all types of SNMP notifications.

·     With entry-consistency specified, if the FIB software and hardware entries on a module are inconsistent, the device sends an SNMP notification that carries the module number to the SNMP module.

·     With entry-limit specified, when the number of FIB entries exceeds the upper limit, the device sends an SNMP notification that carries the FIB entry module name to the SNMP module.

·     With deliver-failed specified, when FIB entry deployment to the hardware fails, the device sends an SNMP notification that carries the entry VRF, IP address type, IP address, mask, and failure reason to the SNMP module.

For the SNMP notifications to be sent correctly, you must also configure SNMP. For more information about SNMP configuration, see Network Management and Monitoring Configuration Guide.

Examples

# Disable SNMP notifications for FIB events.

<Sysname> system-view

[Sysname] undo snmp-agent trap enable fib

snmp-agent trap enable ip-forwarding

Use snmp-agent trap enable ip-forwarding to enable SNMP notifications for IP forwarding events.

Use undo snmp-agent trap enable ip-forwarding to disable SNMP notifications for IP forwarding events.

Syntax

snmp-agent trap enable ip-forwarding [ ttl-expired | mbuf-alloc ]

undo snmp-agent trap enable ip-forwarding

Default

SNMP notifications for IP forwarding events are enabled.

Views

System view

Predefined user roles

network-admin

Parameters

ttl-expired: Specifies notifications about TTL timeout.

mbuf-alloc: Specifies notifications about MBUF allocation failures.

Usage guidelines

This feature enables the IP forwarding module to generate SNMP notifications for critical IP forwarding events. The SNMP notifications are sent to the SNMP module. For the SNMP notifications to be sent correctly, you must also configure SNMP. For more information about SNMP configuration, see Network Management and Monitoring Configuration Guide.

You can enable SNMP notifications for the following IP forwarding events as needed:

·     After you enable SNMP notifications about TTL timeout, the device checks the number of dropped packets at the specified time interval. An SNMP notification is generated and sent to the SNMP module when the number of dropped packets reaches or exceeds the specified threshold.

·     After you enable SNMP notifications about MBUF allocation failures, an SNMP notification is generated and sent to the SNMP module when MBUF allocation fails.

If you do not specify any parameters, the command enables all types of SNMP notifications for IP forwarding events.

After you disable the SNMP notifications for IP forwarding events, the device sends only logs to the device's information center module. In this case, you can configure the log output destinations and output rules to view the log information of the basic IPv6 modules. For more information about configuring the information center, see information center configuration in Network Management and Monitoring Configuration Guide.

Examples

# Disable SNMP notifications for IP forwarding events.

<Sysname> system-view

[Sysname] undo snmp-agent trap enable ip-forwarding