Defining Permanent IP Multicast Forwarding Entries

An mroute is a multicast traffic flow (a (Source, Group) entry used for forwarding multicast traffic). By default, forwarding mroutes (with a valid RPF incoming interface) are timed out if data for them is not received for 210 seconds. However, you can specify an mroute as permanent by using the ip multicast-routing permanent-mroute command.

ip multicast-routing permanent-mroute

• Use to specify that any newly created mroutes that match the specified access-list do not time out.
• Using this command does not change existing mroutes.
• Permanent mroutes are removed if a topology change occurs that affects the mroute.
• Permanent mroutes may be removed due to certain protocol actions (for example, PIM sparse-mode switching from shared to shortest-path tree).
• Outgoing interface lists of permanent mroutes may change due to protocol actions.
• Example

  host1(config)#ip multicast-routing permanent-mroute routes1

• Use the no version to prevent any new mroutes from becoming permanent. To remove existing permanent mroutes, use the clear ip mroute command.
• See ip multicast-routing permanent-mroute.