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Questions: Multicast Traffic Not Crossing Router

  • Is IP multicast routing enabled globally on the router?
  • Is PIM (Protocol Independent Multicast) configured on the router interfaces for each VLAN?
  • Which PIM mode is being used (sparse, dense, sparse-dense)?
  • Is IGMP snooping enabled on the switches, and is the IGMP querier configured?
  • Does show ip mroute show any multicast routing entries?
  • Are IGMP group memberships visible on the router interfaces (show ip igmp groups)?
  • Is there an RP (Rendezvous Point) configured if PIM sparse mode is in use?
  • Are multicast packets being received by the router on the source VLAN interface?
  • Is there an ACL or firewall blocking multicast traffic on the router?
  • Is TTL on the multicast packets sufficient to traverse the router (TTL > 1)?