IGMP snooping problem

prosperot

Regular Contributor
My AX88U seems to have IGMP snooping problems.

Every 5 minutes or so, the STB of my IPTV freezes and claims it has lost its network connection.
Changing IMGP versions on my router (from V3 to V2 or back) resolves the problem, but only for 5 mins or so and then the IPTV freezes again.
I tried to change the fast leave option too, but this made no difference...

Both STB's are directly connected to the router by UTP cable.

Any other ideas I can try?

...corrected the typo in title..
 
Last edited:

ColinTaylor

Part of the Furniture
I think you mean "multicast routing", not IGMP snooping which is something completely different.

P.S. It's IGMP not IMPG.

Has this ever worked before?

What STBs are you using?
 

prosperot

Regular Contributor
never worked properly, both STB are Arris 5202
 

ColinTaylor

Part of the Furniture
Does it work if only one STB is connected to the router?

Who is your IPTV provider? Do they use multicast routing at all or do they just use a VLAN on a dedicated LAN port?
 

prosperot

Regular Contributor
Does it work if only one STB is connected to the router?

Who is your IPTV provider? Do they use multicast routing at all or do they just use a VLAN on a dedicated LAN port?
It does work if I connect only 1 , KPN is my provider and they use multicast, not VLAN on a dedicated LAN port
 

drinkingbird

Very Senior Member
It does work if I connect only 1 , KPN is my provider and they use multicast, not VLAN on a dedicated LAN port

Does your router have the option to disable IGMP snooping on the IPTV page? You can try that to see if it is an issue with snooping or not. The only impact will be when watching TV, the multicast will be flooded to all LAN ports but it's probably 10-20 megs max so not a big deal, especially for just testing. If it resolves the issue, it is probably fine to leave it disabled. You could check another wired device to see what kind of network data it is receiving and if the CPU is being impacted, but most wired NICs will have no issue dropping/ignoring that traffic pretty silently.

You can also try different LAN ports, often a LAN ASIC will cover 2 or 4 ports and sometimes things can be resolved by either having both ports on the same ASIC (sequential ports) on on different ones (like port 1 and 8). I have no idea the architecture of your particular router, just a thought.

Or it could be nothing to do with your network, maybe those two boxes are somehow interfering with each other or confusing each other. Seems unlikely but never know. Don't suppose you have an ISP provided router to test with?
 

ColinTaylor

Part of the Furniture
It does work if I connect only 1 , KPN is my provider and they use multicast, not VLAN on a dedicated LAN port
Is having more than one IPTV box connected to your provider allowed or do they restrict it to just one device?
 

prosperot

Regular Contributor
It should be allowed, anyway it works, untill the box freezes, a change of IGMP protocol does work, but only for 5 mins or so
 

drinkingbird

Very Senior Member
It should be allowed, anyway it works, untill the box freezes, a change of IGMP protocol does work, but only for 5 mins or so

Have you confirmed if you have the option to disable snooping in your router (some do, some don't) if so given that a try? If snooping is not functioning properly, it will prune the multicast group from that port and your STP will lose the connection.
 

prosperot

Regular Contributor
According to my service provider, snooping should be enabled?
 

ColinTaylor

Part of the Furniture
Which LAN ports are the STBs plugged into? As @drinkingbird suggested, the LAN ports on the AX88U are managed by two separate switch chips. Make sure both devices are plugged into ports 1 to 4. (see here)
 

drinkingbird

Very Senior Member
Which LAN ports are the STBs plugged into? As @drinkingbird suggested, the LAN ports on the AX88U are managed by two separate switch chips. Make sure both devices are plugged into ports 1 to 4. (see here)

Or if that doesn't work, could even try ports 5 and 6 (or any two ports in 5-8), appears this router is doing some sort of "double bridge" on ports 5-8. Odd setup, but who knows maybe it will help with multicast.
 

prosperot

Regular Contributor
In the end it appeared that my NT fibre box had a dodgy UPT port.. After replacing it, it all work well now, thanks for all your help!
 

Similar threads

Latest threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top