Configuring Longest Match for Multicast Route Selection

If the longest match principle is configured for route selection, an optimal intra-domain unicast route, an optimal inter-domain unicast route, and an optimal multicast static route are selected. One of them is finally selected as the multicast data forwarding path.

Context

Configurations related to VPN instances apply only to PE devices. When configuring the longest match of multicast routes for a VPN instance on a PE, perform the configuration in the VPN instance. In other cases, the longest match is configured in the public network instance.

If the longest match principle is configured for route selection, a multicast device prefers the route with the longest matched mask. If the mask lengths of multiple routes are the same, the device selects a route as the multicast data forwarding path in the order of the static multicast route, inter-domain unicast route, and intra-domain unicast route.

By default, a route with the highest priority is selected.

Perform the following steps on the multicast router:

Procedure

Configure longest match of multicast routes in the public network instance.
1. Run system-view
  The system view is displayed.
2. Run multicast longest-match
  Routes are selected based on the longest match rule.
3. Run commit
  The configuration is committed.
Configure longest match of multicast routes in the VPN instance.
1. Run system-view
  The system view is displayed.
2. Run ip vpn-instance vpn-instance-name
  The VPN instance view is displayed.
3. Run multicast longest-match
  Routes are selected based on the longest match rule.
4. Run commit
  The configuration is committed.