Question

A financial trading floor uses a Layer 2 switch to distribute a market-data multicast stream to a few subscribed servers. Network engineers notice that the multicast traffic is flooding to every port in the VLAN, including hosts that never joined the group, saturating uninvolved links. Routing and PIM are operating correctly on the upstream router. Which action on the access switch will restrict the multicast frames to only the ports with interested receivers?

Accepted Answer

Enable IGMP snooping on the VLAN so the switch learns which ports have receivers from their IGMP membership reports

Answer

Configure PIM sparse-mode on the switch's SVI to build a shared tree toward the receivers

Answer

Enable an IGMP querier only on the upstream router and remove the switch from the multicast path

Answer

Apply storm control on the receiver ports to police the multicast rate below the link capacity