360
Chapter 9
Multicast
Multicast route tables are somewhat different. Here is a sample of a mul-
ticast table. Notice that the notation is different. Instead of having the des-
tination address listed and then the next hop to get to the destination, source
tree uses the notation of (S, G). This notation specifies the source host's IP
address and the multicast group address for which it is sourcing information.
Let's take the first one, for example. This is seen as (198.32.163.74,
224.2.243.55), which means that the source host is 198.32.163.74 and it is
sourcing traffic for the multicast group 224.2.243.55:
(198.32.163.74, 224.2.243.55), 00:01:04/00:01:55, flags: PT
Incoming interface: POS1/0/0, RPF nbr 208.124.237.10, Mbgp
Outgoing interface list: Null
(198.32.163.74, 224.2.213.101), 00:02:06/00:00:53, flags: PT
Incoming interface: POS1/0/0, RPF nbr 208.124.237.10, Mbgp
Outgoing interface list: Null
(195.134.100.102, 224.2.127.254), 00:00:28/00:02:31, flags: CLM
Incoming interface: POS1/0/0, RPF nbr 208.124.237.10, Mbgp
Outgoing interface list:
FastEthernet4/0/0, Forward/Sparse, 00:00:28/00:02:54
FastEthernet4/1/0, Forward/Sparse, 00:00:28/00:02:31
(207.98.103.221, 224.2.127.254), 00:00:40/00:02:19, flags: CLM
Incoming interface: POS1/0/0, RPF nbr 208.124.237.10, Mbgp
Outgoing interface list:
FastEthernet4/0/0, Forward/Sparse, 00:00:41/00:02:53
FastEthernet4/1/0, Forward/Sparse, 00:00:41/00:02:19
(128.39.2.23, 224.2.127.254), 00:04:43/00:02:06, flags: CLMT
Incoming interface: POS1/0/0, RPF nbr 208.124.237.10, Mbgp
Outgoing interface list:
FastEthernet4/0/0, Forward/Sparse, 00:04:43/00:02:43
FastEthernet4/1/0, Forward/Sparse, 00:04:43/00:03:07
(129.237.25.152, 224.2.177.155), 00:17:58/00:03:29, flags: MT
Incoming interface: POS1/0/0, RPF nbr 208.124.237.10, Mbgp
Outgoing interface list:
FastEthernet4/0/0, Forward/Sparse, 00:17:58/00:02:44
Figure 9.12 gives you a good picture of how source trees work.
Copyright ©2000 SYBEX , Inc., Alameda, CA
www.sybex.com