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Multicast data seems to be going to all lan ports.

Posted: Wed Jan 25, 2017 7:09 pm
by tomabcd
I have a Mikrotik router RB2011ViAS-IN that has port 1 setup for the Wan and all of the others as the LAN.
The router is setup to provide DHCP address out the lan ports.
I have a HDMI to IP encoder connected to port 4 setup to provide a 3 Mb Multicast IP video stream.
I have 2 PCs connected to ports 3 and 8.
I login to the router and clicked on the interfaces button and can see the network traffic on each interface.

On ether4 (encoder) it is showing around 3Mb RX
On ether3 & ether8 (PCs) it is showing around 3Mb Tx.
My problem is neither PC is connected to the Multicast stream. So it seems the router is just blasting the data to everyone regardless if they want the stream or not.

Is this expected? Is there some setting in the router so the stream is only sent to PCs that request it?

I ran an app (igmpquery) and it did NOT show any igmp connection between the PCs and the streaming source.
If I started a stream on a PC then igmp did show a connection from the streaming source to the PC.

Thanks
Tom

Re: Multicast data seems to be going to all lan ports.

Posted: Wed Jan 25, 2017 7:29 pm
by andriys
Is this expected? Is there some setting in the router so the stream is only sent to PCs that request it?
Here's a short answer. Yes, it is expected. And no, there's nothing you can do about it right now. A somewhat longer answer follows.

There are means (PIM, IGMP proxy) in RouterOS to manage multicast traffic on L3 (i.e. when doing routing). However RouterOS has nothing to offer to deal with multicast traffic on L2 (i.e. when doing switching), no matter if your are switching in hardware or via a software bridge. If one port in switching group or bridge sends or receives multicast traffic, this traffic is always unconditionally broadcasted via the rest of the ports in the group. You can search the forum to see that IGMP snooping support has already been requested multiple times here, so please do not post yet another feature request. :) There's no ETA, it's not even clear if this feature is ever implemented at all.

Re: Multicast data seems to be going to all lan ports.

Posted: Wed Jan 25, 2017 8:43 pm
by tomabcd
Ok, so multicast is only blocked/controlled when routing, so can I setup the unit so that I am routing between all of the ports and then setup the routing to allow the IGMP proxy stuff through?

Port 1 - wan
Port 2 - Encoder
Port 3 - 10

So this would mean the Port 3 would need to be bridged to Port 2 and another bridge to port 1. (I think)

I realize that this will be a performance hit.

Re: Multicast data seems to be going to all lan ports.

Posted: Wed Jan 25, 2017 9:01 pm
by andriys
can I setup the unit so that I am routing between all of the ports and then setup the routing to allow the IGMP proxy stuff through?
Yes, you can.
Port 1 - wan
Port 2 - Encoder
Port 3 - 10

So this would mean the Port 3 would need to be bridged to Port 2 and another bridge to port 1.
No. Bridging is essentially the same as switching, but done in software. And you need routing.

Where this encoder should stream to?

Re: Multicast data seems to be going to all lan ports.

Posted: Thu Jan 26, 2017 1:21 am
by w0lt
We need IGMP Snooping!! :(

Re: Multicast data seems to be going to all lan ports.

Posted: Sun Nov 25, 2018 7:28 pm
by lpt2007
Anybody solve this problem?

I installed multicast and enable snooping in bridge, but not working.

https://wiki.mikrotik.com/wiki/Manual:I ... P_Snooping

command:
interface bridge mdb print

show nothing, still multicasting on all ports in bridge at the same time

Re: Multicast data seems to be going to all lan ports.

Posted: Sun Nov 25, 2018 7:45 pm
by eftomi

Re: Multicast data seems to be going to all lan ports.

Posted: Sun Nov 25, 2018 9:49 pm
by lpt2007