PowerConnect B-Series FCX Configuration Guide 74353-1002266-01PIM Sparse 25FIGURE 122 Example of a PIM Sparse domainPIM Sparse switch typesSwitches that are configured with PIM Sparse interfaces also can be configured to fill one or moreof the following roles:• PMBR – A PIM switch that has some interfaces within the PIM domain and other interfaceoutside the PIM domain. PBMRs connect the PIM domain to the Internet.NOTEYou cannot configure a Dell routing interface as a PMBR interface for PIM Sparse in the currentsoftware release.• BSR – The Bootstrap Router (BSR) distributes RP information to the other PIM Sparse switcheswithin the domain. Each PIM Sparse domain has one active BSR. For redundancy, you canconfigure ports on multiple switches as candidate BSRs. The PIM Sparse protocol uses anelection process to select one of the candidate BSRs as the BSR for the domain. The BSR withthe highest BSR priority (a user-configurable parameter) is elected. If the priorities result in atie, then the candidate BSR interface with the highest IP address is elected. In the example inFigure 122, PIM Sparse switch B is the BSR. Port 2/2 is configured as a candidate BSR.• RP – The RP is the meeting point for PIM Sparse sources and receivers. A PIM Sparse domaincan have multiple RPs, but each PIM Sparse multicast group address can have only one activeRP. PIM Sparse switches learn the addresses of RPs and the groups for which they areresponsible from messages that the BSR sends to each of the PIM Sparse switches. In theexample in Figure 122, PIM Sparse Switch B is the RP. Port 2/2 is configured as a candidateRendezvous Point (RP).PIM SparseSwitch BPort2/1207.95.8.10Port2/2207.95.7.1Rendezvous Point (RP) pathPort3/8207.95.8.1Port3/8207.95.7.2VE 1207.95.6.1VE 1207.95.6.2Shortest Path Tree (SPT) pathPIM SparseSwitch A PIM SparseSwitch C209.157.24.162Source for Group239.255.162.1Receiver for Group239.255.162.1This interface is also theBootstrap Router (BR) forthis PIM Sparse domain, andthe Rendezvous Point (RP) for thePIM Sparse groups in this domain.
