Hello, can someone please help me, I have been tearing my hair out with this problem for the last few days without success.
I have a 3750 with IP Services Image. On Monday I will have a phone system on VLAN7 My Voice VLAN that will send multicast traffic that needs to be recevied by an App on some PCs on VLAN3. The 3750 is routing between the VLANs.
As the system is not here I have been testing multicast using VLC which can send and receive from Multicast addresses. Although I can send and receive multicast on the same VLAN as I would expect I cannot get it to work across VLANs using PIM.
I am now totally confused about how it should work. The switch by default has IGMP snooping enabled.
My first question relates to how it should work with just one VLAN. The thing is I dont want that multicast stream broadcast out every port on the switch in the same VLAN as the sender, as the devices on that VLAN do not want to receive the stream, but that is what appears to be happening. A test device on the same VLAN as the stream sender that is not interested in the stream is receiving it, I can see this via tcpdump.
But when I look on the switch it seems to know about where to send the stream...
I love coming across a very old post that solves my problem. This post perfectly described my situation, right down to the hair pulling. The answer that @Harold Ritter gave also perfectly solved my problem. The app I was using had TTL set for 1. Wouldn't have thought to check for that.
FYI, if you want to enable multicast routing across VLANS on a switch, do NOT enable igmp snooping querier. It won't help and it will be disabled anyways when you enable PIM on the SVI.