how does ipv6 multicast effect a non-ipv6 enabled cisco router?

[casmith]

We are seeing high CPU utilizations in the access switches and local workstations are having problems.  The switches and routers are not setup for IPv6.  Workstations are configured with IPv6 and IPv4 enabled.  A wireshark trace indicates a problem with IPv6 multicast traffic.  How does IPv6 traffic effect routers and switches that are setup for IPv4?

[Harold Ritter]

Hi Casey,

This could be due to the acess switched not supporting MLD snooping (ipv6 equivalent to igmp snooping). If MLD snooping is not supported, the multicast stream is flooded to all port on the switch.

Regards