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Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 29 Configuring IP Unicast Routing
Configuring BFD
If you only want to run IS-IS BFD on a few interfaces, instead of enabling it globally, you can enter the
isis bfd interface configuration command on those interfaces. See the next procedure.
Note
Although IS-IS BFD operates only on Layer 3 interfaces, you can configure it on interfaces in Layer 2
or Layer 3 mode. When you enable it, you see this message:
%ISIS BFD is reverting to router mode configuration, and remains disabled.
This is an example of setting fast convergence and configuring BFD for IS-IS on all IS-IS interfaces:
Switch(config)#
router is-is tag1
Switch(config-router)#
bfd all-interfaces
Switch(config-router)#
exit
Configuring BFD for IS-IS on an Interface
Beginning in privileged EXEC mode, follow these steps to configure IS-IS BFD on an individual
interface:
To disable IS-IS BFD on an interface, enter the no isis bfd or the isis bfd disable interface configuration
command on the interface.
This is an example of configuring BFD for IS-IS on a single interface:
Switch(config)#
router is-is tag1
Switch(config-router)#
exit
Switch(config)#
interface gigabitethernet0/1
Switch(config-if)#
isis bfd
Configuring BFD for BGP
When you start BFD sessions for BGP, BGP must be running on all participating devices. You enter the
IP address of the BFD neighbor to enable BFD for BGP.
Beginning in privileged EXEC mode, follow these steps to enable BGP BFD:
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
router is-is area-tag
Specify an IS-IS process and enter router configuration mode.
Step 3
exit
Return to global configuration mode.
Step 4
interface interface-id
(Specify an interface, and enter interface configuration mode.
Step 5
isis bfd
Enable BFD on the specified IS-IS interface. Repeat Steps 3 and 4 for all
IS-IS interfaces on which you want to run BFD sessions.
Step 6
end
Return to privileged EXEC mode.
Step 7
show bfd neighbors [detail]
Verify the configuration.
Step 8
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
router bgp as-tag
Specify a BGP autonomous system, and enter router configuration mode.