Configuring Static BFD for IPv4 IS-IS

BFD can provide link failure detection featuring light load and high speed (at the millisecond level). Static BFD can be configured to monitor IS-IS links.

Context

In a static BFD session scenario, you need to configure single-hop BFD parameters, such as local and remote discriminators and then configure the device to send BFD session setup requests.

A static BFD session can only be established and released manually. A configuration error will lead to a BFD failure. For example, if a local or remote discriminator is incorrectly configured, a BFD session will not work properly.

Procedure

Enable BFD globally.
1. Access the system view.
  system-view
2. Enable BFD.
  bfd
3. Access the system view.
  quit
Configure a single-hop BFD session.
1. Enable BFD between the specified interface and peer router.
  bfd bfd-name bind peer-ip ip-address [ interface interface-type interface-number ]
  
  If a peer IP address and a local interface are specified in the bfd command, BFD monitors only a single-hop link with the interface specified in the bfd command as the outbound interface and with the peer IP address specified in the peer-ip command as the next-hop address.
2. Set discriminators.
  - Set a local discriminator.
    
    discriminator local discr-value
  - Set a remote discriminator.
    
    discriminator remote discr-value
  The local discriminator of a device must be the remote discriminator of the device on the other end; otherwise, a BFD session cannot be established. In addition, the local and remote discriminators cannot be modified after being configured.
  
  The local discriminator set using the local discr-value command on a device must be the same as the remote discriminator set using the remote discr-value command on the device of the other end.
3. Commit configurations.
  commit
4. Access the system view.
  quit
Enable static BFD on an interface.
1. Access the interface view.
  interface interface-type interface-number
2. Enable static BFD.
  isis bfd static