Concept Guide
• If other destination prexes in the prex-list are pointing to the same neighbor, then the no permit or the deny option on a
particular destination prex neither creates a BFD session on a neighbor nor removes the static routes from the unicast database.
• BFD sessions created using any one IP prex list are active at any given point in time. If a new prex list is assigned, then BFD sessions
corresponding to the older (existing) prex list are replaced with the newer ones.
• Each time a prex list is modied, only addition or deletion of new entries in that prex list are processed for BFD session establishment
or tear down.
Changing Static Route Session Parameters
BFD sessions are congured with default intervals and a default role.
The parameters you can congure are: Desired TX Interval, Required Min RX Interval, Detection Multiplier, and system role. These
parameters are congured for all static routes. If you change a parameter, the change aects all sessions for static routes.
To change parameters for static route sessions, use the following command .
• Change parameters for all static route sessions.
CONFIGURATION mode
ip route bfd [prefix-list prefix-list-name] interval milliseconds min_rx milliseconds
multiplier value role [active | passive]
To view session parameters, use the show bfd neighbors detail command.
Disabling BFD for Static Routes
If you disable BFD, all static route BFD sessions are torn down.
A nal Admin Down packet is sent to all neighbors on the remote systems, and those neighbors change to the Down state.
To disable BFD for static routes, use the following command.
• Disable BFD for static routes.
CONFIGURATION mode
no ip route bfd [prefix-list prefix-list-name] [interval interval min_rx min_rx multiplier
value role {active | passive}]
Congure BFD for IPv6 Static Routes
BFD oers systems a link state detection mechanism for static routes. With BFD, systems are notied to remove static routes from the
routing table as soon as the link state change occurs, rather than waiting until packets fail to reach their next hop.
Conguring BFD for IPv6 static routes is a three-step process:
1 Enable BFD globally.
2 Congure static routes on both routers on the system (either local or remote).
3 Congure an IPv6 route to connect BFD on the static routes using the ipv6 route bfd command.
Related Conguration Tasks
• Changing IPv6 Static Route Session Parameters
• Disabling BFD for Static Routes
Bidirectional Forwarding Detection (BFD)
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