Administrator Guide
Scenario Output
-3 10.10.10.1 PIM No route default
--------------------------------------------------------------
----
If a multicast tree is not formed due to a
conguration issue (for example, PIM is not
enabled on one of the interfaces on the
path), you can invoke a weak mtrace to
identify the location in the network where the
error has originated.
R1>mtrace 6.6.6.6 4.4.4.5
Type Ctrl-C to abort.
Querying reverse path for source 6.6.6.6 to destination
4.4.4.5 via RPF
From source (?) to destination (?)
--------------------------------------------------------------
---
|Hop| OIF IP |Proto| Forwarding Code |Source Network/
Mask|
--------------------------------------------------------------
---
0 4.4.4.5 --> Destination
-1 4.4.4.4 PIM
6.6.6.0/24
-2 20.20.20.2 PIM 6.6.6.0/24
-3 10.10.10.1 PIM Multicast disabled 6.6.6.0/24
--------------------------------------------------------------
----
If the destination provided in the command is
not a valid receiver for the multicast group,
the last hop router for the destination
provides the WRONG LAST HOP error code.
If the last-hop router contains a path to the
source, the path is traced irrespective of the
incorrect destination.
R1>mtrace 6.6.6.6 5.5.5.5 234.1.1.1
Type Ctrl-C to abort.
Querying reverse path for source 6.6.6.6 to destination
4.4.4.5 via group 234.1.1.1
From source (?) to destination (?)
--------------------------------------------------------------
---
|Hop| OIF IP |Proto| Forwarding Code |Source Network/
Mask|
--------------------------------------------------------------
---
0 5.5.5.5 --> Destination
-1 5.5.5.4 PIM Wrong Last-Hop
6.6.6.0/24
-2 20.20.20.2 PIM 6.6.6.0/24
-3 10.10.10.1 PIM 6.6.6.0/24
-4 6.6.6.6 --> Source
--------------------------------------------------------------
----
If a router in the network does not process
mtrace and drops the packet resulting in no
response, the system performs an expanding-
hop search to trace the path to the router
that has dropped mtrace. The output of the
command displays a ‘*’ indicating that no
response is received for an mtrace request.
The following message appears when the
system performs a hop-by-hop search:
“switching to hop-by-hop:”
R1>mtrace 99.99.99.99 1.1.1.1
Type Ctrl-C to abort.
Querying reverse path for source 99.99.99.99 to destination
1.1.1.1 via RPF
From source (?) to destination (?)
* * * * switching to hop-by-hop:
--------------------------------------------------------------
---
|Hop| OIF IP |Proto| Forwarding Code |Source Network/
Mask|
--------------------------------------------------------------
---
0 1.1.1.1 --> Destination
-1 1.1.1.1 PIM -
99.99.0.0/16
-2 101.101.101.102 PIM -
99.99.0.0/16
606 Multicast Features