Supported Platforms
Enabling Point-to-Point LSPs to Monitor Egress PE Routers
Configuring an LSP with the associate-backup-pe-groups statement enables it to monitor the status of the PE router to which it is configured. You can configure multiple backup PE router groups using the same router's address. A failure of this LSP indicates to all of the backup PE router groups that the destination PE router is down. The associate-backup-pe-groups statement is not tied to a specific backup PE router group. It applies to all groups that are interested in the status of the LSP to that address.
To allow an LSP to monitor the status of the egress PE router, include the associate-backup-pe-groups statement:
This statement can be configured at the following hierarchy levels:
- [edit protocols mpls label-switched-path lsp-name]
- [edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
If you configure the associate-backup-pe-groups statement, you must configure BFD for the point-to-point LSP. For information about how to configure BFD for an LSP, see Configuring BFD for MPLS IPv4 LSPs and Configuring BFD for LDP LSPs.
You also must configure a full mesh of point-to-point LSPs between the PE routers in the backup PE router group. A full mesh is required so that each PE router within the group can independently determine the status of the other PE routers, allowing each router to independently determine which PE router is currently the designated forwarder for the backup PE router group.
If you configure multiple LSPs with the associate-backup-pe-groups statement to the same destination PE router, the first LSP configured is used to monitor the forwarding state to that PE router. If you configure multiple LSPs to the same destination, make sure to configure similar parameters for the LSPs. With this configuration scenario, a failure notification might be triggered even though the remote PE router is still up.
