Having read many, many topics on multicast today I'm feeling pretty lost with it and would appreciate some guidance as what I want to achieve I think is much simpler than many of the guides I've found.
The setup I am working with is two Nexus 9K core switches with a VPC link between them and then a number of Cisco 3650 access switches each connected to both core switches with a port channel. We have a video streaming system with one encoder on one 3650 using multicast to stream video to a number of decoders across other 3650 switches, I created a new VLAN dedicated for this system and had no issues configuring the devices and they can be accessed via IP address without issue.
However the system didn't work and I'd mistakenly thought by having all devices on the same VLAN I wouldn't need any multicast configuration. Because there's no routing onto another VLAN, what is the minimum configuration required on each core switch?
I thought I needed to configure an IGMP snooping querier so assuming it's VLAN 10 I ran the following commands on the first core switch:
vlan configuration 10
ip igmp snooping querier 192.168.10.4
This returned:
Warning: IGMP Snooping should be disabled on peer VPC switch <vlan 10> as well.
Warning: This command should be executed on peer VPC switch <vlan 10> as well.
I then ran the same command on the second core switch but I'm not sure if it should be 4 (1 is the HSRP gateway, 2 is the first core switch, 3 the second so 4 is next free one) or it should be 5. I tried changing the command to 5 but I noticed in the show ip igmp snooping vlan 10 that the IGMP querier was showing 192.168.10.4 and the switch querier showed 192.168.10.5 so I tried running no 192.168.10.5 to remove it entirely but the command still showed the 192.168.10.4 querier
After running this command, the system started working but only for around half the devices making me suspicious something wasn't right on one of the core switches. So I decided for one of the devices that was missing, I'd disable the trunk link to the first core switch and force it over to the second core switch which made it come online on the system (all the devices work fine over normal IP addresses) although swapping the links over it remained online. I then tried the same on the switch with the encoder and with the first core switch disabled, all the devices then came online to the system and it appears to be working correctly now but still working on testing.
If I do a show ip igmp interface, I get output showing VLAN 10 for the first core switch but if I run it on the second I get nothing. If I run show ip igmp snooping querier I get the port as switch querier for the first core switch and pointing back to the VPC port channel if I run on the second core switch. For show ip igmp snooping explicit-tracking vlan 10, I get some items listed on the first core switch but a lot more on the second. I did try some debug commands but I didn't seem to be getting any output.
That's getting wrong and rambling so I'd appreciate if anyone can advise which commands should be run on each core switch (they should be redundant) to get multicast working within one VLAN and the best way to verify it, I'd be very grateful.
