Tracing A Multicast Path - HP MSR ASM Configuration Manual

When the router forwards multicast data, it replicates a copy of the multicast data for each downstream
node and forwards the data. Each of these downstream nodes is a branch of the multicast distribution
tree.
You can configure the maximum number of downstream nodes (namely, the maximum number of
outgoing interfaces) for a single entry in the multicast forwarding table to lessen the burden on the router.
If the configured upper limit is smaller than the number of existing downstream nodes for a forwarding
entry, the downstream nodes in excess are not deleted immediately. The multicast routing protocol that
runs on the router will delete them. The router will no longer update the newly added downstream nodes
for the forwarding entry until the number of existing downstream nodes for the forwarding entry
decreases below the upper limit.
Configuring the multicast forwarding table size for the public network
Step
1. Enter system view.
2. Configure the maximum
number of entries in the
multicast forwarding table.
3. Configure the maximum
number of downstream nodes
for a single multicast
forwarding entry.
Configuring the multicast forwarding table size in a VPN instance
Step
1. Enter system view.
Enter VPN instance view.
2.
3. Configure the maximum
number of entries in the
multicast forwarding table.
4. Configure the maximum
number of downstream nodes
for a single route in the
multicast forwarding table.

Tracing a multicast path

You can use the mtracert command to trace the path down which the multicast traffic flows from a given
first-hop router to the last-hop router.
To trace a multicast path:
Command
system-view
multicast forwarding-table
route-limit limit
multicast forwarding-table
downstream-limit limit
Command
system-view
ip vpn-instance vpn-instance-name
multicast forwarding-table
route-limit limit
multicast forwarding-table
downstream-limit limit
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Remarks
N/A
Optional.
The default is the maximum number
allowed by the system. The
maximum value depends on your
device model. For more
information, see IP Multicast
Command Reference.
Optional.
The default value is 128.
Remarks
N/A
N/A
Optional.
The default is the maximum number
allowed by the system. The
maximum value depends on your
device model. For more
information, see IP Multicast
Command Reference.
Optional.
The default value is 128.