To perform redistribution, the device maintains a route change list. The change list contains all the best routes that are either added to or deleted from the forwarding table. When a best route is added to or deleted from the forwarding table, the change list is updated to reflect the change and notify registered protocols. The registered protocols pick up the change from the change list when it becomes available.
An example scenario of interVRF redistribution follows. To redistribute OSPF routes in VRF 1 to RIP in VRF 0:
Create, enable, and apply a RIP redistribution instance. The source protocol is OSPF and the VRF source is VRF 1.
When an OSPF route is added in VRF 1, the Routing Table Manager (RTM) in VRF 1 puts the new route into the change list.
The device notifies RIP in VRF 0, because RIP is registered with the RTM of VRF 1 for OSPF route changes.
To send OSPF routes from VRF 1 through the RIP interface in VRF 0, the interface uses a route policy with match VRF criterion of VRF 1.
The switch also supports inter-domain multicast routing. For more information, see IP Multicast.