Foundry Networks Switch and Router Installation And Configuration Manual page 680

Foundry Switch and Router Installation and Configuration Guide
Tracing the route for tree 209.157.23.188
0 207.95.7.2
0 207.95.7.2 Thresh 0
1 207.95.7.1 Thresh 0
2 207.95.8.1 Thresh 0
3 207.157.24.62
Syntax: mtrace source <ip-addr> group <multicast-group>
The source <ip-addr> parameter specifies the address of the route's source.
NOTE: In IP multicasting, a route is handled in terms of its source, rather than its destination. When you trace
an IP route, you specify its destination, but when you trace a PIM route, you specify its source.
The group <multicast-group> parameter specifies the PIM group the source IP address is in.
Figure 18.9 shows an example of an IP multicast group. The command example shown above is entered on PIM
router A
PIM router A
BigIron
e2/3
207.95.7.2
e3/11
8.8.8.164
Client
Multicast group
239.255.162.1
Figure 18.9 Example PIM Group
The command example above indicates that the source address 209.157.24.62 is three hops (three PIM routers)
away from PIM router A. In PIM terms, each of the three routers has a forwarding state for the specified source
address and multicast group. The value following "Thresh" in some of the lines indicates the TTL threshold. The
threshold 0 means that all multicast packets are forwarded on the interface. If an administrator has set the TTL
threshold to a higher value, only packets whose TTL is higher than the threshold are forwarded on the interface.
The threshold is listed only for the PIM router hops between the source and destination.
USING THE WEB MANAGEMENT INTERFACE
You cannot trace a PIM route using the Web management interface.
18 - 54
PIM router B
BigIron
e1/4
e1/5
207.95.7.1
207.95.8.10
PIM router C
BigIron
e1/8
207.95.8.1
e3/19
209.157.24.62
Server
Multicast group
239.255.162.1
December 2000