Use the following syntax to configure LSP BFD for LDP.
config
— router
— ldp
— [no] lsp-bfd prefix-list-name
— priority priority-level
— no priority
— bfd-template bfd-template-name
— no bfd-template
— source-address ip-address
— no source-address
— [no] bfd-enable
— lsp-ping-interval seconds
— no lsp-ping-interval
— exit
The lsp-bfd command creates the context for LSP BFD configuration for a set of LDP LSPs with a FEC matching the one defined by the prefix-list-name parameter. The default is no lsp-bfd. Configuring no lsp-bfd for a specified prefix list removes LSP BFD for all matching LDP FECs except those that also match another LSP BFD prefix list. The prefix-list-name parameter refers to a named prefix list configured in the config>router>policy-options context.
Up to 16 instances of LSP BFD can be configured under LDP in the base router instance.
The optional priority command configures a priority value that is used to order the processing if multiple prefix lists are configured. The default value is 1.
If more than one prefix in a prefix list, or more than one prefix list, contains a prefix that corresponds to the same LDP FEC, then the system tests the prefix against the configured prefix lists in the following order:
numerically by priority-level
alphabetically by prefix-list-name
The system uses the first matching configuration, if one exists.
If an LSP BFD is removed for a prefix list, but there remains another LSP BFD configuration with a prefix list match, then any FECs matched against that prefix is rematched against the remaining prefix list configurations in the same manner as described above.
A non-existent prefix list is equivalent to an empty prefix list. When a prefix list is created and populated with prefixes, LDP matches its FECs against that prefix list. It is not necessary to configure a named prefix list in the config>router>policy-options context before specifying a prefix list using the config>router>ldp>lsp-bfd command.
If a prefix list contains a longest match corresponding to one or more LDP FECs, the BFD configuration is applied to all of the matching LDP LSPs.
Only /32 IPv4 and /128 IPv6 host prefix FECs is considered for BFD. BFD on PW FECs uses VCCV BFD.
The source-address command is used to configure the source address of periodic LSP ping packets and BFD control packets for LSP BFD sessions associated with LDP prefixes in the prefix list. The default value is the system IP address. If the system IP address is not routable from the far-end node of the BFD session, then an alternative routable IP address local to the source node should be used.
The system does not initialize an LSP BFD session if there is a mismatch between the address family of the source address and the address family of the prefix in the prefix list.
If the system has both IPv4 and IPv6 system IP addresses, and the source-address command is not configured, then the system uses a source address of the matching address family for IPv4 and IPv6 prefixes in the prefix list.
The bfd-template command applies the specified BFD template to the BFD sessions for LDP LSPs with FECs that match the prefix list. The default is no bfd-template. The named BFD template must first be configured using the config>router>bfd>bfd-template command before it can be referenced by LSP BFD, otherwise a CLI error is generated. The minimum receive interval and transmit interval supported for LSP BFD on LDP LSPs is 1 second.
The bfd-enable command enables BFD on the LDP LSPs with FECs that match the prefix list.