All things related to multicast

[Amel Caldwell <>]

Do you know what group 225.1.2.3 is for?  I was snooping around some WWW sites
and noticed it was one (if not the most popular) in terms of SA entries.  I
noticed this is true on my routers as well, so went looking to find out what
it was by doing a Google search and it looked like a lot of different apps put
that address in as an example.

Amel

On Fri, 22 Jun 2001, Toerless Eckert wrote:

>On Fri, Jun 22, 2001 at 03:16:02PM -0400, Alan Crosswell wrote:
>> In http://www.abilene.iu.edu/content.cgi?page=mc-cookbook it says:
>>
>> >This is the multicast-boundary list we presently use in Abilene, and
>> >there have been some suggestions for additional values for which we're
>> >soliciting feedback/consensus from the I2 community. The expressions
>> >below block sending RP announce and discovery packets and set the
>> >accepted administrative scoping to block 'local' multicast.
>> >
>> >        ip access-list standard multicast-boundary
>> >         deny   224.0.1.39
>> >         deny   224.0.1.40
>> >         deny   239.0.0.0 0.255.255.255
>> >         permit any
>>
>> Is there a more up-to-date list of recommended groups to drop at the
>> boundary? For example, I noticed I am getting NTP from about 8 sources.
>
>I don't think you need to drop more with the boundary-command, it is
>sufficient to discard the rest via MSDP. Just also do an inbound MSDP
>filter. Check out
>
> ftp://ftpeng.cisco.com/ipmulticast/config-notes/msdp-sa-filter.txt
>
>for the latest list of offenders (eg: non 239 group used for scoped
>applications). If you know more, please tell me and i'll add.
>
>Cheers
>       Toerless
>
>