Dell PowerEdge M420 Configuration Manual page 1194

Figure 42-34. Add Candidate RP
3 Select the interface for which the Candidate RP is to be configured.
4 Enter the group address transmitted in Candidate-RP-Advertisements.
5 Enter the prefix length transmitted in Candidate-RP-Advertisements to
fully identify the scope of the group which the router supports if elected as
a Rendezvous Point.
6 Click Apply Changes.
The new Candidate RP is added, and the device is updated.
1194
Managing IPv4 and IPv6 Multicast