static multicast routing

RouterOS General
1

Hi,

is it possible to configure routeros to perform multicast routing according to staticly configured routing table? I’ve got this up&running on linux machine using smcroute, I’m curious if I could replace that machine with routerboard.

I’m just adding simple routes for multicast streams in this fasion:
smcroute -a eth1 10.0.0.11 225.1.1.1 eth2

where eth1 is the input interface, 10.0.0.11 is source ip, 225.1.1.1 is mcast address and
eth2 is target interface. Nothing besides mcast traffic defined in this fashion passes through the router.

I’m thinking about two possibilities how to do this on routeros.

First running just basic config PIM and changing route table(/cache) accordingly. But I don’t know if my configuration will persist for longer time plus I don’t want PIM to change its routing tables according to incoming group joins/leaves. I need to ignore those.

Second, running mcast proxy and somehow denying all multicast traffic except what I say.
This could be the closest, but I don’t know how to do that.

So, how do I do this? Is it even possible? Or is there another possibility how to add multicast routes?

Thanks.

2

main question for me is - do you really need dump packet forwarder that forwards packets just from 1 multicast group. Or your clients are capable to issue and manage joins/leaves etc.
if clients are capable you can easily go with PIM or even with IGMP-proxy
not sure about limiting just to certain IGMP group, actually never looked at it.

3

http://www.mikrotik.com/testdocs/ros/2.9/ip/route.php

4

Let’s say I’ve got two LANs, LAN1 and LAN2, connected together with one router.
Thing is, there are multicast groups I need to keep inside LAN1 (and not allow to cross to LAN2) and vice versa and these groups have the same address in both LANs (and it has to stay this way, don’t ask why.)
And then there are multicast groups that should be transferrend from one LAN to the other all the time, regardless of registered clients. That’s why I need static routing, I need to specify which groups to drop and which to pass forward and I don’t want to mess this configuration up with join requests from either LAN.
In fact the whole thing is a bit more complicated and I don’t want to go to more detail here, just please trust me on this. It has to be done this way.

As for the documentation page, I most certainly had read that, it just doesn’t say anything about multicast routing, which is kind of special case. I just need to know if it’s possible on RouterOS.

Thanks guys.

5

theoretically it is doable (/interface bridge filter and /interface bridge nat) but practically i would suggest to stick with your current solution. :confused:

6

ok, thanks for honest openion :wink:

JFI: I’m now trying to do it with OpenWRT on RB450 with cross-compiled smcroute, I could let you know how that works out if anyone’s interested.

7

4.5 will add that feature. writing on wiki what configuration will be needed to make that work.

here is how it is done:
http://wiki.mikrotik.com/wiki/IGMP-Proxy#Static_multicast_forwarding_cache_.28MFC.29_entries

8

@janisk I’m trying to set this up in my Mikrotik, I have to transport a simple SPTS over multicast IP from one ethernet to another ethernet. I configured IGMP Proxy (quite simple), I can see the traffic increasing in the upstream interface, but the downstream interface doesn’t forward any packet.
At the other side (the downstream interface) I’ve got connected a simple PC with VLC (Not IGMP capable). I need that all the multicast traffic that comes from the upstream interface be forwarded to the downstream interface without the need of any join.
Is this possible to do with IGMP Proxy?.

Thank you.