Technical data

System Administration
303561-A Rev 00
8-81
Viewing the Multicast Table Manager Forwarding Cache
The Multicast Table Manager (MTM) maintains a multicast forwarding cache
table. The
ip mtm
command allows you to view the cache table for a particular
slot. To view the MTM cache, enter the ip command using the following syntax:
ip mtm -s<
slot>
<slot>
is the slot number associated with the MTM cache you want to examine.
You must enter a slot number for the
ip mtm
command.
For the cache entry associated with each (source/group) pair, the command output
indicates a list of incoming circuits, a list of outgoing circuits, and a slot mask
indicating the slots on which there are outgoing circuits.
An incoming circuit is represented by the circuit number and the protocol on that
circuit. An outgoing circuit is represented by the circuit number, the protocol on
the circuit, and the time-to-live (TTL) threshold.
Table 8-10
lists each protocol letter and its meaning.
If the letter denoting the protocol on the incoming circuit is lowercase, the circuit
is a drop circuit (that is, the circuit drops packets for that source/group pair).
The number that follows the protocol letter on an outgoing circuit indicates the
associated TTL threshold. For MOSPF, this threshold may vary per group, source,
or outgoing circuit. For DVMRP or RSVP, this threshold varies only per outgoing
circuit.
Table 8-10. Protocol Letters and Meanings
Protocol Letter Meaning
D The circuit is receiving or transmitting DVMRP path messages for the
flow
R The circuit is receiving or transmitting RSVP path messages for the
flow
M The circuit is receiving or transmitting MOSPF path messages for the
flow
N The protocol on the circuit does not currently have routing information
for the flow