[152624] in North American Network Operators' Group
Re: mulcast assignments
daemon@ATHENA.MIT.EDU (Greg Shepherd)
Thu May 3 18:45:02 2012
In-Reply-To: <4FA30798.2080503@foobar.org>
Date: Thu, 3 May 2012 15:44:23 -0700
From: Greg Shepherd <gjshep@gmail.com>
To: Nick Hilliard <nick@foobar.org>
Cc: nanog@nanog.org
Reply-To: gjshep@gmail.com
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Thu, May 3, 2012 at 3:32 PM, Nick Hilliard <nick@foobar.org> wrote:
> 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. =A0It needs igmpv3 on all intermediate devices and=
SSM
> support on the client device. =A0All 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. =A0This can lead to Unexpected Behaviour in naive
> roll-outs.
I haven't seen a piece of network gear without SSM support in a very
long time. The weak link is the applications. It was the OS stacks but
that's finally caught up - it only took it 10 years...
The weakest link is simply multicast deployment - if it's not
everywhere it has little use. That's what AMT is promising to fix. And
with AMT comes the opportunity to bring SSM to non-SSM-capable apps if
it is implemented correctly.
Greg
> Nick
>
