Comcast Ethernet Feed

Fri Mar 30 02:32:58 UTC 2012

Never mind control and what Comcast says about hard-coding speed and duplex!
The question is:

What happens when you set the int facing Comcast CPE to auto?
Does the link even come up?
*IF* the link comes up, can you ping your next-hop?

If you can, leave auto-neg on despite what what Comcast may say/require.

Post a "sh int gix/y" and "sh int fax/y"

If the above outputs are *clean*, I would say a TAC case is called for.

--- On Thu, 3/29/12, Brian R. Watters <brwatters at absfoc.com> wrote:

> From: Brian R. Watters <brwatters at absfoc.com>
> Subject: Re: Comcast Ethernet Feed
> To: "Randy" <randy_94108 at yahoo.com>
> Cc: "NANOG list" <nanog at nanog.org>
> Date: Thursday, March 29, 2012, 7:02 PM
> 
> 
> A couple of questions - 
> 
> 1) What flavor of NPE are you using?
> 
> NPE-G1
> 
> 2) Is the GigE interface on the NPE-G1/G2  OR is this a
> PA?
> 3) Is the FaE ethernet interface that you appear to be
> connecting your laptop to, on a separate PA in chassis?
> 
> Laptop connected directly to router via slot 4 
> PA-FE-TX
> 
> 4) Have you verified you that "bandwidth-points" have not
> been exceeded for bus-1 and/or 2: slots 1,3,5 for bus1 and
> 2,4,6; also 0(if I/O controller is present. It is 600 points
> for bus1 and 600 for bus2.
> 
> PCI bus mb1 has 390 bandwidth points
> PCI bus mb2 has 500 bandwidth points
> 
> 
> Have you *hard-coded* speed and duplex on any of you eth
> ints? Please don't!
> 
> GIGE has been both hard and auto .. same results .. Fast
> Ether has always been set @ auto
> 
> Let both ints auto-negotiate speed&duplex.
> 
> Comcast states that we are required to have a hard code FULL
> DUPLEX and SPEED 100 as well as flow control OFF however I
> can not appear to be able to disable it :(
> 
> 
> after having done so, post the output of:
> 
> sh int gi x/y and sh int fa x/y
> 
> (hardcoding speed/duplex is sometimes required when dealing
> with brain-dead CPE. I have also seen other flavors of
> brain-dead CPE that *only* work when speed/duplex are set to
> auto)
> 
> ./Randy
> 
> 