Answers to Review Questions
421
Answers to Review Questions
1.
B, D. These two commands must be entered for multicast forward-
ing to work. The ip mroute cache command enhances performance
but is not necessary. CGMP is necessary only when hosts are con-
nected to a router via a Catalyst switch.
2.
B, E. 1100 is an invalid range; the range has to be 199. 100199 is
used for extended access lists and 800899 is used for IPX. 1300
1999 is an expanded range.
3.
B, C, D. IP multicast routing is not part of the Auto-RP configuration.
4.
D, E. Type means interface type, and number means the interface
number.
5.
A. The command enables the multicast process on the router, there-
fore permitting multicast packets to be forwarded.
6.
C. (S, G) and (*, G) are the only valid notations. (S, G) indicates a
source root tree distribution. Dense mode uses source
root trees.
7.
A. (S, G) and (*, G) are the only valid notations. (*, G) indicates a
shared root tree distribution. Sparse mode uses shared root trees.
8.
A, C. RP Mapping Agents keep track of all RP routers in the network
via their unicast address. They then provide the nearest RP for the
multicast groups it sources to all leaf routers in the multicast network.
9.
C. The correct way to limit the scope of the multicast network is to
configure TTL thresholds for external or border interfaces. RPF is
used strictly for reverse path lookup.
10.
D. By subscribing to a multicast group, the router can execute certain
commands to troubleshoot and verify multicast connectivity.
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