Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 953)

Multi-Service IronWare Switching Configuration Guide 923
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Configuring BFD for the specified protocol
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The holdover interval can be configured globally.
If the bfd holdover-interval is set to 20 seconds, when a notification is received from BFD that the
BFD session has moved to DOWN state, the system waits for 20 seconds before sending the BFD
session down notification to OSPFv3 state machine. If the BFD session returns to UP state before
the 20 seconds expires, the OSPFv3 state machine is not notified that the BFD session flapped.
Otherwise, after 20 seconds the BFD session down notification is passed to the OSPFv3 state
machine. If BFD for OSPFv3 is disabled, the request to not use BFD for OSPFv3 is passed to BFD by
OSPFv3, BFD acknowledges this request, and the BFD session is removed. If BFD is disabled,
OSPFv3 is notified and asks BFD to remove the single hop BFD session on the interface.
To configure the BFD down notification delay, enter a command such as the following.
Brocade(config-ospf6-router)# bfd holdover-interval 10
Syntax: [no] bfd holdover-interval time-seconds
The time-seconds variable is a number between 0 and 20 seconds. The default is 0 seconds.
The no option removes the BFD holdover interval from the configuration.
Configuring BFD for IS-IS
You can configure your device for BFD (for both IPv4 and IPv6 IS-IS neighbors) for the IS-IS protocol
for all IS-IS enabled interfaces, or for specific interfaces as shown in the following sections.
NOTE
You will not be able to configure a BFD for IS-IS session when one side of the IS-IS adjacency is using
IPv4 only and other side is using IPv6 Only.
Enabling BFD for IS-IS for all interfaces
You can configure IS-IS for IS-IS on all S-IS enabled interfaces for a device using this command.
Brocade# router isis
Brocade(config-isis-router)# bfd all-interfaces
Syntax: [no] bfd all-interfaces
Although this command configures BFD for IS-IS on all IS-IS enabled interfaces on the device, it is
not required if you use the isis bfd command to configure specific interfaces. It can be used
independently or together with the isis bfd command.
Enabling or disabling BFD for IS-IS for a specific interface
You can selectively enable or disable BFD on any IS-IS interface as shown in the following.
Brocade(config-if-e1000-3/1)# isis bfd
Syntax: [no] isis bfd [disable]
The disable option disables BFD for IS-IS on the interface.
Holdover interval
The BFD holdover interval is supported for single hop sessions. It sets the time by which the BFD
session DOWN notification to ISIS is delayed. If within that holdover time, the BFD session is UP
then ISIS is not notified of the BFD session flap.