What does an asterisk indicate in the output of the show ip pim tunnel command? (Select the best answer.)
A. The router is an RP.
B. Fast switching is enabled.
C. The entry includes all multicast sources.
D. The neighbor has been learned through an assert.
An asterisk in the output of the show ip pim tunnel command indicates that the router is a rendezvous point (RP). An RP is a well-connected, centrally located router
that is responsible for keeping track of multicast group membership information. Protocol Independent Multicast sparse mode (PIMSM) requires an RP, whereas
PIM dense mode(PIMDM) does not. When PIMSM is used, each multicast receiver must be able to reach the RP through a connected tree of PIMSM routers. If a
router along the path is not configured for PIMSM, multicast receivers will not be able to register with the RP and multicast traffic will not flow to those receivers.
When you issue the show ip pim tunnel command on an RP, you will receive output that is similar to the following:
An RP will always have a PIM Encap and a PIM Decap tunnel interface. Additionally, anasterisk will appear next to the RP IP address.
An asterisk in the output of the show ip pim interface count command indicates thatfast switching is enabled. The show ip pim interface count command also
displays how many multicast packets have been received and sent by each interface. The following output is from the show ip pim interface count command:
An asterisk in the output of the show ip mroute command indicates that an entryincludes all multicast sources or that a neighbor has been learned through an
assert. The show ip mroute command displays the multicast routing table. Shared distribution trees are specified by a (*,G) notation? the * indicates all sources, and
the G indicates the multicast group address. Source distribution trees, which are also known as shortest path trees (SPTs), are specified by an (S,G) notation? the
S indicates the address of the multicast source, and the G indicates the multicast group address. PIMSM supports both shared distribution trees and source
distribution trees and can use both (S,G) and (*,G) routes. PIMDM supports only source distribution trees, and PIMDM groups use only (S,G) routes. The following
output from the show ip mroute command shows both types of routes:
If an asterisk appears next to the RPF nbr IP address, the neighbor has been learned through an assert. Asserts are used to elect a designated forwarder (DF).
DFs are elected to ensure a loop-free tree with the root at the RP. The router with the lowest cost to the RP will become the DF on a network segment.