On my home network I use alot of enterprise equipment. Mostly for testing purposes but it does give me some strange problems from time to time.
A while ago I noticed that all my switches and wireless equipment would start flashing like someone did a multicast storm of some sort so I enabled IGMP snooping to avoid any multicast storms etc. I later turned it off on most of my equipment as I found it to be my Canon MP970 software on my PC that did a complete ping scan of the network to look for printers.
I later noticed that when I wanted to play music, video or show pictures over DLNA then it didn’t work when I was connected with wireless equipment. This could be my phone or my laptop. I am using Trapeze Networks wireless equipment which has it’s own controller and directly attached AP’s and distributed AP’s. For some strange reason it just didn’t work.
I tried googling DLNA and Trapeze Networks and also DLNA and Juniper WLA (Since they bought Trapeze Networks) but nothing came up.
This made me read up on DLNA and it ofcourse turns out that DLNA uses multicast to send contents over the network. A quick search for Multicast and wireless on Junipers knowledge base and soon found that I ofcourse had enabled IGMP Snooping on my wireless equipment.
I logged on to the console of the MXR-2 controller with SSH and ran the following command:
MXR-2# set igmp disable
Seconds after all DLNA equipment responded from my phone! This is great!
So if your DLNA equipment is not responding you should check that you do not have IGMP Snooping enabled on any of your switches, routers and wireless equipment. Even though this is a great safety for packet storms it is bad news for DLNA equipment.s