51
Description
Use
mtracert
to trace the path down which the multicast traffic flows to the last-hop router.
If the command to trace the path for a specific (S, G) multicast stream includes the
last-hop-router-address
argument, the interface that corresponds to the last-hop router address must be the outgoing interface for
the (S, G) entry. Otherwise, the multicast traceroute might fail.
Examples
# Trace the path down which the (6.6.6.6, 225.2.1.1) multicast traffic flows to the last-hop router with an
IP address of 5.5.5.8.
<Sysname> mtracert 6.6.6.6 5.5.5.8 225.2.1.1
Type Ctrl+C to quit mtrace facility
Tracing reverse path of (6.6.6.6, 225.2.1.1) from last-hop router (5.5.5.8) to source
via multicast routing-table
-1 5.5.5.8
Incoming interface address: 4.4.4.8
Previous-hop router address: 4.4.4.7
Input packet count on incoming interface: 17837
Output packet count on outgoing interface: 0
Total number of packets for this source-group pair: 8000
Protocol: PIM
Forwarding TTL: 0
Forwarding code: No error
-2 4.4.4.7
Incoming interface address: 6.6.6.7
Previous-hop router address: 0.0.0.0
Input packet count on incoming interface: 2
Output packet count on outgoing interface: 259
Total number of packets for this source-group pair: 8100
Protocol: PIM
Forwarding TTL: 0
Forwarding code: No error
Table 12
Command output
Field Description
(6.6.6.6, 225.2.1.1)
(S, G) multicast stream for which the forwarding path is being traced
-1 5.5.5.8
(S, G) outgoing interface address of each hop, starting from the last-hop
router
Incoming interface address
IP address of the interface that received the (S, G) packets
Previous-hop router address
IP address of the previous router that forwards the packets to the current
router
Input packet count on incoming
interface
Total number of multicast packets that the incoming interface received
Output packet count on
outgoing interface
Total number of multicast packets that the outgoing interface transmitted
