All things related to multicast

[Toerless Eckert <>]

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