(Optional) Configuring Dynamic BFD for IPv6 Static Routes
Applicable Environment
Preferred IPv6 static routes are delivered to the forwarding table for packet forwarding. An IPv6 static route, however, is incapable of detecting whether the link to the next hop is working properly. Binding the IPv6 static route to a BFD session can address this problem, because a BFD session is capable of detecting link changes and informing the routing management module of the changes. If a BFD session detects that a link is interrupted, the routing management module immediately withdraws the IPv6 static route that is bound to the BFD session from the forwarding table and recalculates another active route. In this manner, fast route convergence is implemented.
Pre-configuration Tasks
Before configuring dynamic BFD for IPv6 static routes, complete the following task:
Configuring link layer protocol parameters and IPv6 addresses for interfaces to ensure that the link layer protocol on the interfaces is Up
Procedure
- Run system-view
The system view is displayed.
- Run bfd
Global BFD is enabled on the node.
- Run quit
Return to the system view.
- (Optional) Run ipv6 route-static default-bfd { min-rx-interval min-rx-interval | min-tx-interval min-tx-interval | detect-multiplier multiplier }*
The global BFD parameters of the IPv6 static routes on the device are set.
The default values of the global BFD parameters min-rx-interval, min-tx-interval, and multiplier are 1000 ms, 1000 ms, and 3 respectively.
- Run ipv6 route-static bfd [ interface-type interface-number ] nexthop-address [ local-address ipv6-address ] [ detect-multiplier multiplier | min-rx-interval min-rx-interval | min-tx-interval min-tx-interval ]*
The BFD parameters of an IPv6 static route are set.
If interface-type interface-number is not set, local-address ipv6-address must be specified.
If none of min-rx-interval, min-tx-interval, and detect-multiplier is specified, the global default values of the BFD parameters are used.
- Run ipv6 route-static dest-ipv6-address prefix-length { interface-type interface-number [ nexthop-ipv6-address ] | vpn-instance vpn-instance-name nexthop-ipv6-address | nexthop-ipv6-address } [ preference preference | tag tag ]* bfd enable [ description text ]
A BFD session is bound to an IPv6 static route.
When the type and number of the outbound interface of a static route are specified, and the VPN instance name is specified, a static route searches the routing table of the VPN instance for an outbound interface according to nexthop-address. Run the ipv6 route-static vpn-instance vpn-source-name dest-ipv6-address prefix-length { interface-type interface-number [ nexthop-ipv6-address ] | vpn-instance vpn-destination-name nexthop-ipv6-address | nexthop-ipv6-address [ public ] } [ preference preference | tag tag ]* bfd enable [ description text ] command to bind a dynamic BFD session to static routes.
- Run commit
The configuration is committed.
Verifying the Configuration
Information about a BFD session can be viewed only after the parameters of the BFD session are set and the BFD session is established.
Run the following commands to check the previous configuration.
Run the display bfd session { all | discriminator discr-value } [ verbose ] command to check information about BFD sessions.
Run the display current-configuration | include bfd command to check configurations of BFD for IPv6 static routes.