Did you get the problem resolved? Which version of the firmware works fine with the IPTV/IGMP snooping?

" This is an absolutely vital feature for IPTV - without IGMP, multicast streams aren't properly directed to the devices viewing those streams, but instead convert into broadcast streams that flood all LAN jacks and WLAN connections"

No they don't if you disable multicast. They just become point to point like other IP traffic. It's only an issue if you wanted to have multiple destinations but not others sharing the SAME stream which is the reason to use multicast.

I know what multicast is, and not having it is a massive issue when your IPTV provider requires multicast streaming.

"Entertain TV" in Germany is the market leader by a huge margin. Their streams are multicast straight from the provider's central server source, all the way to the settop boxes. It plain and simply doesn't work unless everything in the chain does multicast correctly.

There is simply no arguing that - and if one vendor's devices don't have the feature, Entertain customers will have to shop elsewhere. The other two popular PLC vendors in Germany (AVM, devolo) have working multicast in their products, and they are perfectly aware that it's vital.

As powerline is effectively shared bandwidth anyway, I can't see that it makes much difference if the powerline devices send multicast as broadcast anyway.

It does where traffic egresses from the PLC segment, and that's the point. If the ingress PLC (at the router) converts all the multicast traffic into broadcast, then every single thing on the far end of the PLC net will get flooded - be that an endpoint device, WLAN AC, LAN switch or VoIP hub. And worse, since it's broadcast traffic now, all the WLAN APs will flood the air with mass broadcast traffic as well.

Like I said, when you have multicast traffic as a use case, there's simply no arguing around the fact that your infrastructure devices MUST handle it properly.

TP-Link's PLC product lineup is a real mess in this regard, customers can't see what they get - and even then they can't rely on it staying as it was when purchased. Some (like those of this topic) originally had it and got it removed by firmware update, some others (like the TL-PA8030P) had it added in V2 even though it hasn't been advertised, others again (like TL-PA8030P V1) had it working but the latest beta didn't have it anymore - and the best ones are those that explicitly advertise the feature (like the EasySmart switches) but need years of waiting for a firmware update that finally gets it right ... and by the next time you buy one, you get a new hardware version and start all over.

What I specifically dislike about this topic is not the arguing though - it's the fact that literally the minute I posted my original message, the text on the download page got changed to remove the "disable IGMP" information. The firmware binary was not changed, just the vital information obfuscated.

Not trying to argue - just trying to help and make sure it really matters - as per the above it wouldn't in some use cases.

Are you sure it actually breaks multicast for remote multicast aware devices? These are fairly dumb PLCs. It would be more likely that it would simply forward multicast to all addresses - and also forward IGMP requests. In that case yes your PLCs would be flooded, but multicast aware devices across the connection might well still work as expected? Haven't tested it though.

Yes I can see it sucks.

Multicast-unaware network setups don't break the multicast stream - what happens is everything else becomes unusably slow while there is streaming activity. Then in secondary consequence, the streaming device may fail to communicate back to its host too. And then, things fall completely apart as soon as two clients subscribe to the same stream, or when two different streams are in use.

For example, when I still had the TL-PA8030P V1, the WLAN AP in the upstairs study became completely useless when someone watched TV on the PC in the same room (Entertain TV lets you do that). PC and AP were directly on the 8030P. The LAN switch in the 8030P would broadcast the PC's subscribed TV stream onto the WLAN AP as well, and the AP would of course broadcast the stream to all its connected wireless clients. The wireless clients' WLAN performance was completely down the drain, and so was battery usage. Replace with a TL-PA8030P V2 with very latest firmware, and all is fine.

Get it all right, have multicast-aware routers, WLAN APs, LAN switches and PLCs (including their integrated LAN switches!), and it'll be smooth. Have one item that lacks the feature, and it will break - in the most undebuggable ways you can imagine.

So for peace of mind, customers want products that clearly state "multicast support - YES" right there on the box, and customers must be able to rely on it actually working ... and also rely on it not quietly disappearing in a firmware update.