Cisco Static Multicast routing on layer 3 switch

[seblebirhanu69]

I have a question regarding static multicast configuration on a Cisco device. Is it possible to have static multicast route only with out PIM configuration? we have another 3'rd party router connected to cisco switch which does not support PIM.

Is it possible to use static for both, or can I use PIM for Cisco and static for a 3rd party switch?

[Cristian Matei]

Hi,

   Short answer, no; without PIM there's no multicast happening, with or without a static mroute; static mroute can only tell PIM not to use unicast RIB when building the tree.

Best,

Cristian.

[seblebirhanu69]

Thank you so much; it was very helpful. However, my concern is whether a Cisco switch with PIM configured can work with a third-party device that only runs static multicast routing. In our design, there are two switches running PIM and one switch with only static routing. Is this compatible?

[Cristian Matei]

Hi, 

    Short answer, not possible.

Best,

Cristian.

[MHM Cisco World]

Both sender and receiver in same vlan?

MHM

[seblebirhanu69]

It's not on the same VLAN. I tested between PC A and PC B, and I can send and receive multicast traffic. However, I would like to know the standard way to handle this issue when we have two devices—one with PIM configured and the other supporting only static multicast. (simple test network design shown below) 

[Cristian Matei]

Hi,

    When you say you have it working, you mean it works when you don't have the Cisco switch in the transit path, right? Please confirm.

    Now, when you have multiple layer 3 hops between sender and receiver, making it work without PIM (assuming we speak about Cisco or Juniper devices), it's impossible; if the network topology is simple (between sender and receiver), like in your case, you can use static mroutes on the non Cisco switches (if this is what this vendor makes multicast work) and use MVR on Cisco side (instead of PIM): https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/15-1SY/config_guide/sup2T/15_1_sy_swcg_2T/ipv4_mvr.html

Best,

Cristian.

[seblebirhanu69]

Cisco is configured PIM and the 3'rd party L3 switch is configured static multicast routing. 

[Joseph W. Doherty]

For the test topology, what I believe will work all depends on configurations around the Cisco<>3rdParty link.

On the Cisco interface you use the command (IP igmp static-group) to always send a specific multicast IP out the interface.

On 3rd party device, you statically route the traffic on both interfaces.

Basically both Cisco and 3rd party are working as if the multicast source is on the connecting link.

In the above, I'm also allowing multicast in either direction.  If multicast was only in one direction, configuration needs would be less.

[Joseph W. Doherty]

Hmm, long time ago had a mixed hardware environment, half Cisco and half brand X (this in an environment with a couple hundred routers).  Brand X didn't support PIM, it did support DVMRP.

I recall (?) Cisco supported one way transfer of mroutes, although don't recall which direction.

I mention the forgoing to ask whether the non Cisco equipment supports DVMRP. If it does, possibly you have some additional options.

What you want to do might (?) be accomplished, statically, is by treating one side or the other or perhaps both sides as having host(s) that don't support IGMP.  I.e. statically send selected multicast traffic into the necessary networks.  Basically, a flood of specific mulicast traffic, whether desired or not.  Understand, the flood only happens when the multicast is being generated, but if it is being generated, it's forwarded.

For better suggestions, please provide the topology and source and destinations of the multicast traffic.