[c-nsp] SSM and multicast IP addresses

netman netman at oneidatel.net
Sat Feb 10 21:55:23 EST 2007


I can't thank this list enough for the responses I have recevied to my 
questions. Hopefully I can return some answers in the future.

I did use the wrong terms. Instead of soure I should have used multicast 
group. Anyway, testing SSM I had things working with the 232.x.x.x 
addresses. So then I decided to try the 224.1.1.x address for SSM using the 
'ip pim ssm
 range' command. That worked fine also.

The whole plan is to carry about 480 meg of multicast traffic over the 
7600's to each company (7 Foundry's and 1 Cisco 6500). The Cisco is mine, so 
I know what I can do with it. I have very little experience on the 
Foundry's.
Now my problem is at the edge will be Foundry Big Irons. I have 8 Cisco 
7604s' for the transport of the multicast (10 gig between all the 7604's). I 
am dropping off 1 or 2 gigabit ports to the Foundry's.

I understand the Foundry's will support SSM (but not ssm mapping like 
Cisco), but the STB's hanging off the Foundry's do not (they support 
IGMPv2). So I need to test and see if the 7604 will take the IGMPv3 request 
from the Foundry and be able to map it using SSM.
or
I am also wondering if the Foundry's even need to run IGMPv3. I am wondering 
if they use igmp static-group commands on the Foundry if that will be good 
enough. Of course, I do not have a Foundry chassis to test with, so I need 
to work around a production network.

Thanks for the great responses on this list. The details that have been in 
everyone's responses has been great!!

Don Hickey

----- Original Message ----- 
From: "Asbjorn Hojmark - Lists" <lists at hojmark.org>
To: "'netman'" <netman at oneidatel.net>
Cc: <cisco-nsp at puck.nether.net>
Sent: Saturday, February 10, 2007 4:39 PM
Subject: RE: [c-nsp] SSM and multicast IP addresses


>> In order for Source Specific Multicast (SSM) to work properly,
>> does the source addresses need to be in the 232.x.x.x range?
>
> You mean the multicast (not source) addresses?
>
> No, it doesn't need to be 232.0.0.0/8. You can configure another
> range (or in fact several other ranges) using the 'ip pim ssm
> range' command.
>
> 232.0.0.0/8 is reserved for SSM, but if you're planning to talk
> to other networks, consider using 233.0.0.0/8 and GLOP (RFC3180).
>
>> Will SSM work with source addresses in the 224.1.x.x range?
>
> I'm still assuming you mean multicast address (not source),
> because that's what it is.
>
> Yes, SSM will work with 224.1.0.0/16, but you really shouldn't
> use that, as it's reserved for other purposes.
>
> See http://www.iana.org/assignments/multicast-addresses
>
>> Also does anyone know if Foundry supports SSM?
>
> Yes, Foundry supports SSM, but AFAIK not SSM maps like Cisco. So,
> basically, it'll only work with IGMPv3 clients if used at the
> edge.
>
> -A
>
> 



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