trying to figure out problem thats been bugging me for a while. We do have several setups like this and even bigger, but only this one has this particular problem.
Lets keep it simple.
All of the not needed connections have been shutdown (like optics out of this stack...) so there are basically only router and stack. Stack is "OK"
There are several multicast sources and currently there are few destinations. The moment i shutdown port , or bring it up (port that is a part of iptv (multicass) there is a multicast storm to destination ports and of course our source "coordinator" - it is windows 2012r2 machine , there is a wireshark and this is what i m getting during the storm (see pic from wireshark) - various ips 10.40.20.x are multicast sources that normaly do not do this there is like 1mbps receiving part. Now it goes to 80-100mbps.
This is on the router for the said vlan interface
ip address 10.40.20.254 255.255.252.0
ip pim sparse-dense-mode
ip nat inside
ip virtual-reassembly in
zone-member security LAN
switch of course is snooping
IGMP snooping : Enabled
IGMPv2 immediate leave : Disabled
Multicast router learning mode : pim-dvmrp
CGMP interoperability mode : IGMP_ONLY
Robustness variable : 2
Last member query count : 2
Last member query interval : 1000
Topology change : No
show ip igmp snooping groups | count 406
Number of lines which match regexp = 12
after manual checking yes, there are currently 12 multicast groups on switch for the 406 VLAN
version that the stack is running
System image file is "flash:/c2960x-universalk9-mz.152-7.E5/c2960x-universalk9-mz.152-7.E5.bin"
I ve tried to make switch querier and severed the connection after that with router. Groups still do work, but so does the multicast storm during shutdown / no shutdown
During this event when i do show controllers util , i can see how they are transmitting and there are 2 100mbps consumere devices that are on 100percent. After a while (like 30 - 60 seconds) this will pass.
anyone little help ? Can post full configs if needed.