Configuring an LDP Label Advertisement Filter

To configure an LDP label advertisement filter, use the following command:
configure mpls ldp advertise [{direct [all | lsr-id | none]} | {rip [all | none] | {static [all | none]}

This command configures a filter to be used by LDP when originating unsolicited label mapping advertisements to LDP neighbors.

You can configure how the direct advertisement filter is applied, as follows:

  • direct—The advertisement filter is applied to the FECs associated with direct routes.
  • rip—The advertisement filter is applied to the FECs associated with RIP routes.
  • static—The advertisement filter is applied to the FECs associated with static routes.

You can configure the advertisement filter, as follows:

  • all—Unsolicited label mappings are originated for all routes of the specified type (direct, RIP, or static).
  • lsr-id—An unsolicited label mapping is originated if a /32 direct route exists that matches the MPLS LSR ID. This filter is the default setting for direct routes and is only available for direct routes.
  • none—No unsolicited label mappings are originated for all routes of the specified type. This is the default setting for RIP and static routes.

You can control the number of labels advertised using the configure mpls ldp advertise command. Advertising labels for a large number of routes can increase the required number of labels that must be allocated by LSRs. Care should be used to insure that the number of labels advertised by LERs does not overwhelm the label capacity of the LSRs.