Configuring PIM Sparse Mode Join Filters for IPv4

You can use PIM sparse mode join filters to prevent multicast state from being created in the PIM sparse mode router. The filters are applied to join entries in PIM join/prune messages that are received from PIM sparse mode neighbors.

By denying joins at the edge of a network, you can limit the multicast state and traffic in the network. By accepting only certain joins, you can control which multicast services an end user can receive. PIM join filters also reduce the potential for denial of service (DoS) attacks where large numbers of joins forwarded to each router on the RPT can result in a PIM state explosion and very high memory consumption.

For information about how to create access lists, see Configuring Routing Policy in the JunosE IP Services Configuration Guide.

To specify an extended access list that you want this PIM interface to use as a join filter:

• Issue the ip pim join-filter command in Global Configuration mode:
  host1(config)#ip pim join-filter gold

  The no version removes the filter association. You can apply the join filter at the global level or at the interface level. If an interface-level filter exists, it takes precedence over the global-level filter.

Note: You can configure PIM on IPv4 and IPv6 interfaces. However, IPv6 does not support all PIM configuration options. For information about configuring PIM on IPv6 interfaces, see Configuring PIM for IPv6 Multicast.

Related Documentation

• Understanding PIM for IPv4 Multicast
• Configuring the PIM for IPv4 Join/Prune Message Interval
• Configuring an RP Router for PIM Sparse Mode and PIM Sparse-Dense Mode for IPv4
• Configuring BSR and RP Candidates for PIM Sparse Mode for IPv4
• Configuring PIM for IPv4 SSM
• Configuring the BFD Protocol for PIM for IPv4
• Monitoring PIM for IPv4 Multicast
• ip pim join-filter