All things related to multicast

[Matthew Davy <>]

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I believe that should be 0.0.0.0/8 *not* 0.0.0.0/0 :)

My personal opinion is that all the IANA reserved space should be  
filtered (eg 235/8, 236/8, etc) at domain borders.    However, when I  
suggested this at a Joint Tech's a few years ago, several people were  
quite opposed to this.     Passing 236/8 interdomain is no different  
than passing 10/8, both are IANA reserved addresses and, IMO,  
everyone should be filtering these at domain borders.

The other point you made regarding rate-limiting is a good one as  
well.   We already do per-peer SA limiting.    We also have the  
ability to do per-source SA limiting.    There was a thread on this  
list a while back about implementing some per-source SA limits.    My  
opinion is that limiting each source IP to some relatively large  
number of different groups (say 1,000) on the backbone is a good  
thing for the overall stability of multicast and wouldn't hinder any  
legitimate use of multicast.    But, again, I think the consensus  
that last time this was discussed was that the backbone shouldn't do  
that type of limiting.    Is that still the consensus ?

Also, in terms of Bill's and Cisco's lists being out of date, I'm  
sure they are.    However, I think it's the most complete list out  
there today.   If there are other groups that should be added, we'll  
certainly consider adding them.

- - Matt


On May 25, 2006, at 12:40 PM, John Kristoff wrote:

> On Thu, 25 May 2006 12:11:16 -0400
> Matthew Davy 
> <>
>  wrote:
>
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> > NEW ABILENE MSDP FILTER
> >
> >    sources:
> >      (0.0.0.0/0,*)          Link Local Addresses
>
> Do you mean 0.0.0.0/32 or perhaps even the entire reserved block of
> 0.0.0.0/8?
>
> Bill's draft and Cisco list are not so up to date considering the
> multicast swamp gets polluted quicker than anyone would like and I
> am not actively maintaining the page I started for hardening anymore.
> It sort of depends on where your priorities are for filtering.  If
> you want to cut down on bogus MSDPs, clearly filtering the reserved
> /8's are going to make a much bigger difference than the control
> plan overlapping /24's, but if you want be conservative then maybe
> focus on rate limiting strategies to minimize state and flooding
> explosion?
>
> John

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