Anything unique that needs configuring for Multicast & NAT on FWSM?

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Nov 1st, 2007
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Is there anything special that needs configuring for receiving Multicast through a FWSM running software 3.1x? Multicast routing is enabled and the correct RP is defined. We have the appropriate ACL's configured to allow PIM, IGMP & all Mutlicast groups ( and we are seeing the PIM joins leave the outside interface. I need to put a sniffer on the link to the ISP but I was wondering if there is anything I am missing in this configuration before I start getting the sniffer out?

I know the ISP supports Multicast before anyone points out this may be the issue...

Cheers, Andy

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dominic.caron Mon, 11/05/2007 - 06:59
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I had problem with multicast routing and version 3.1.X of the FWSM code. In the end, if you only want to join multicast session, your better of in pass-tru mode.

If you need to source multicast session, try the most recent version of FWSM code. There a lot of bugfix in the release notes. I'm at 3.1.4(9) and I'm still having problem(sometime it work, sometime it dont)

andrew.butterworth Tue, 11/06/2007 - 11:40
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Thanks for the reply Dominic. It isn't really feasible to swap from routed to transparent since this is an established FWSM on a customers network (I assume you meant Transparent with the pass-thru comment?).

It does seem there are bugs with Multicast in software 3.1.x so it may be we are just running into them. I need to get back on site and do some more debugging. I just thought I would post in case there was some 'magic' button that needed switching first....



dominic.caron Tue, 11/06/2007 - 13:19
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Actually, I meant the IGMP Proxy feature.

I've had some problem with PIM, I've got hundreds of cameras streaming multicast flow. Some flow where not registering with the RP(my core routers). Same type of encoder, some worked, some would not.(and not always the same) And it works fine with the SUP as the router.


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