Hey All,
Scenario:
We have a switch stack of 3750's and the desktop people are trying to ghost/image. The stack is an access layer stack with no layer 3 and igmp snooping is enabled by default. All machines in this scenario are on 1 vlan and we'll call it X. They start the ghost session using multicast and then join (we'll say 5 computer, could be 20+). The desktops connect fine and the ghosting starts. During the course of the ghosting, there is some hesitation and pausing but after a prolonged amount of time they finish successfully. There is no mrouter defined on upstream layer 3 interface as its all on the same vlan.
Results and findings:
While the ghost session is running I notice that alot of other ports with machines on the same vlan (X) are receiving the ghost/image even though they are not participating. This is bad for us as we have 100+ workstations on that stack/vlan that are receiving an image that they don't need.
If I enable ip pim sparse-dense mode on upstream layer 3 interface, everything seems good and just the clients in the session get the image. So my question is:
Do you HAVE to have a querier/mrouter (either layer 3 interface or switch itself) in order for igmp snooping to actually work even if all traffic is on 1 switch/stack?
Thanks,
Craig
