Multicast GRT-source/VRF-receiver (GRT/VRF) extranet with per-group mapping allows multicast traffic to flow from GRT into VRF MVPN instances. A VRF routing instance that received a PIM/IGMP join but cannot reach the source multicast stream directly within its own instance is selected as receiver routing instance. A GRT instance that has sources of multicast streams and accepts PIM joins from other VRF MVPN instances is selected as source routing instance.
Figure 1 shows a sample deployment.
Routing information is exchanged between GRT and VRF receiver MVPN instances of extranet by enabling grt-extranet under a receiver MVPN PIM configuration for all or a subset of multicast groups. When enabled, multicast receivers in a receiver routing instance(s) can subscribe to streams from any multicast source node reachable in GRT source instance.
The main feature attributes are:
GRT/VRF extranet can be performed on all streams or on a configured group of prefixes within a receiver routing instance.
GRT instance requires Classic Rosen multicast.
IPv4 PIM joins are supported in receiver VRF instances.
Local receivers using IGMP: (C-S, C-G) and (C-*, C-G) using SSM translation are supported.
The feature is blocked if a per-group mapping extranet is configured in receiver VRF.