All things related to multicast

[Bill Owens <>]

On Tue, May 30, 2006 at 01:11:55PM -0400, Matthew Davy wrote:
> So based on http://www.iana.org/assignments/multicast-addresses,  
> which seems to be the authoritative source of multicast address  
> assignment, the IANA reserved space is:
> 
> 224.1.0.0 - 224.1.0.37  Reserved                            [IANA]
> 224.1.0.39 - 224.1.0.255 Reserved                           [IANA]
> 224.1.5.0 - 224.1.255.255 Reserved                          [IANA]
> 224.3.0.64 - 224.3.255.255     Reserved                        [IANA]
> 224.5.0.0 - 224.251.255.255  Reserved                          [IANA]
> 225.0.0.0 - 231.255.255.255 Reserved                 [IANA]
> 234.0.0.0 - 238.255.255.255 Reserved                     [IANA]

A quick count, we have 2739 MSDP SAs in our NYC router just now, and about 
690 of them would be blocked by this filter. I have no idea whether they are 
in the table because of unintentional leakage, or stupid application writers, 
or perhaps are actually being used. The largest single group in the reserved 
range is 234.21.81.1 has 271 sources, and is used by LimeWire. Of course, the 
largest group is 'legit' in that it has been approved by IANA, but probably 
shouldn't be getting out to the world; 224.1.0.38 (that's Retrospect, the 
backup software, to save everyone from having to look). 313 sources. And our 
old friend 224.0.1.76, the IAPP group, is hanging in there with 111 access 
points chiming away. 
 
> IMO this is definitely the "right thing" to do (regardless of the  
> benefits) and would go a long way to accomplishing all the potential  
> goals that Bill Owens mentioned.

I wasn't advocating for those goals; I was listing them as a question for the 
group, to try to ascertain goal or goals we're aiming at. 

Bill.