Experiences with Comcast Ethernet/Transit service

Holmes,David A dholmes at mwdh2o.com
Mon Jan 4 18:00:26 UTC 2010

I do not know of Comcast's Ethernet services specifically, but a general problem with carrier Ethernet services that are based upon the Metro Ethernet Forum (MEF) is that PIM-snooping is not implemented for multicast traffic. The absence of PIM-snooping results in the carrier's Ethernet service operating like a 1990's style Ethernet hub in which (S,G) multicast packets are incorrectly flooded out all user ports. 

If multicast traffic is to be used on the carrier Ethernet service, and there is more than one user location, then make sure that the carrier understands the implications of the lack of PIM-snooping support.

-----Original Message-----
From: Brandon Galbraith [mailto:brandon.galbraith at gmail.com] 
Sent: Wednesday, December 23, 2009 1:11 AM
To: nanog at nanog.org
Subject: Experiences with Comcast Ethernet/Transit service

We're looking at using Comcast's (business) transit and private ethernet
services at several client locations and I wanted to see what experiences
others have had regarding this. Off-list replies are preferred.


Brandon Galbraith
Mobile: 630.400.6992

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