mulcast assignments

Thu May 3 22:32:56 UTC 2012

On 03/05/2012 21:00, Greg Shepherd wrote:
> Sure, but GLOP predated SSM, and was really only an interim fix for
> the presumed need of mcast address assignments. GLOP only gives you a
> /24 for each ASN where SSM gives you a /8 for every unique unicast
> address you have along with vastly superior security and network
> simplicity.

SSM is indeed a lot simpler and better than GLOP in every conceivable way -
except vendor support.  It needs igmpv3 on all intermediate devices and SSM
support on the client device.  All major desktop operating systems now have
SSM support (OS/X since 10.7/Lion), but there is still lots of older
hardware which either doesn't support igmpv3 or else only supports it in a
very primitive fashion.  This can lead to Unexpected Behaviour in naive
roll-outs.

Nick