IGMP Snooping Port Mask.
This allows configuration of IGMP Snooping on selected ports.
IGMP Snooping cannot be enabled on an interface that has routing
enabled, or is a member of a LAG. If a port which has IGMP Snooping
enabled becomes enabled for routing, or is enlisted as a member of a
LAG, IGMP Snooping functionality will be disabled on that port. IGMP
Snooping functionality will be subsequently be reenabled if routing is
disabled or LAG membership is removed from an interface that had previously
had IGMP Snooping enabled.
To obtain port numbers from interface numbers, use the objects
agentPortDot1dBasePort and agentPortIfIndex in the agentPortConfigTable
table.