[c-nsp] Multicast

[lists at Hojmark.ORG]

Scenario is a network running PIM-SM (SSM) and a customer running
PIM-DM. It has been agreed that the SP must deliver a number of
groups to the customer no matter if the customer asks for them.

They have configured 'ip igmp static <group>' on the customer-
facing interface, but it doesn't seem to be stable. Some groups
flow constantly, while others expire (the expire timer runs out).

Shouldn't 'ip igmp static <group>' be enough to make the group
flow constantly?

-A