Advanced Configuration and Management Guide
Tracing the route for tree 209.157.23.188
0 207.95.7.2
0207.95.7.2 Thresh 0
1207.95.7.1 Thresh 0
2207.95.8.1 Thresh 0
3207.157.24.62
Syntax: mtrace source
The 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
Figure 9.9 shows an example of an IP multicast group. The command example shown above is entered on PIM router A
PIM router A |
| PIM router B | PIM router C | |
e2/3 | e1/4 | e1/5 | e1/8 | |
207.95.7.1 | ||||
207.95.7.2 | 207.95.8.10 | 207.95.8.1 | ||
| ||||
e3/11 |
|
| e3/19 | |
8.8.8.164 |
|
| 209.157.24.62 | |
Client |
|
| Server | |
Multicast group |
|
| Multicast group | |
239.255.162.1 |
|
| 239.255.162.1 |
Figure 9.9 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.
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