HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual page 524

Configuring Multicast Support for a Stub Network
Troubleshooting Multicast Stub Routing and IGMP
10-22
4. If the correct group membership exists, then the router should know to
forward multicast messages into the host's network. You should verify
that the router is receiving the multicast messages. View the status of the
upstream interface with the show interfaces command and check that
it is receiving multicast packets.
5. If the router is not receiving messages, you may have a problem with IGMP
proxy. Hosts in a stub network can only receive multicasts from remote
networks if the stub router runs IGMP proxy. IGMP proxy problems
include:
• The downstream interface is not running IGMP proxy. Enter show ip
igmp interface and look for the helper address. (See Figure 10-7.)
• If the helper address is "disabled," move to the configuration mode
context for the interface and enter:
ProCurve(config-eth 0/1)# ip mcast-stub helper-enable
If you have not done so, you must also configure the helper address
from the global configuration mode context:
ProCurve(config)# ip mcast-stub helper-address 10.10.10.1
• If the helper address is "enabled," the interface is running IGMP proxy.
Verify that the helper address is correct in the running config. Also
check connectivity using the ping command. The router must, of
course, be able to reach the multicast device at the central site. If
necessary, troubleshoot a connection. (See the Basic Management
and Configuration Guide, Chapter 6: Configuring the Data Link
Layer Protocol for E1, T1, and Serial Interfaces, Chapter 7: ADSL
WAN Connections, and Chapter 8: Configuring Demand Routing for
Primary ISDN Modules.)
• In an inactive network, you can add the router stack to the multicast
group (ip igmp join <A.B.C.D>) and use the ping, debug, and
traceroute commands to determine whether the multicast source is
receiving joins from the router.
6. If the router is receiving messages but is not forwarding them, try viewing
the multicast routing table. Enter:
ProCurve# show ip mroute
It should include the interface that directly connects to the network in
question as an outgoing interface and the upstream interface as the
incoming interface.