Concept Guide

– Forwarding code — error code as present in the response blocks
– Source Network/Mask — source mask
Example of the mtrace Command to View the Network Path
The following is an example of tracing a multicast route.
R1>mtrace 103.103.103.3 1.1.1.1 226.0.0.3
Type Ctrl-C to abort.
Querying reverse path for source 103.103.103.3 to destination 1.1.1.1 via group 226.0.0.3
From source (?) to destination (?)
-----------------------------------------------------------------
|Hop| OIF IP |Proto| Forwarding Code |Source Network/Mask|
-----------------------------------------------------------------
0 1.1.1.1 --> Destination
-1 1.1.1.1 PIM Reached RP/Core 103.103.103.0/24
-2 101.101.101.102 PIM - 103.103.103.0/24
-3 2.2.2.1 PIM - 103.103.103.0/24
-4 103.103.103.3 --> Source
------------------------------------------------------------------
The following table explains the output of the mtrace command:
Table 66. mtrace Command Output — Explained
Command Output Description
Querying reverse path for source
103.103.103.3 to destination 1.1.1.1 via
group 226.0.0.3
mtrace traverses the reverse path from the given destination to the given
source for the given group
From source (?) to destination (?)
In case the provided source or destination IP can be resolved to a hostname
the corresponding name will be displayed. In cases where the IP cannot be
resolved, it is displayed as (?)
0 1.1.1.1 --> Destination
The rst row in the table corresponds to the destination provided by the
user.
-1 1.1.1.1 PIM Reached RP/Core
103.103.103.0/24
The information in each of the response blocks is displayed as follows:
• o (-1) Hop count is always a negative number to indicate reverse path
• o (1.1.1.1) Outgoing interface address at that node for the source and
group
• o (PIM) Multicast protocol used at the node to retrieve the information
• o (Reached RP/Core) Forwarding code in mtrace to denote that RP
node is reached
• o (103.103.103.0/24) Source network and mask. In case (*G) tree is
used, this eld will have the value as (shared tree). In case no value is
noted in the record or in case of error like No Route or Wrong Last Hop
the value (default) will be displayed
-4 103.103.103.3 --> Source The last line in the table corresponds to the source address provided by the
user.
Supported Error Codes
Error codes denote problems in the network that has caused the mtrace query to fail.
These codes not only provide error information but also provide general information such as RP node reachability information.
642
Multicast Features