nanog mailing list archives

Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy

From: "William Herrin" <herrin-nanog () dirtside com>
Date: Thu, 2 Aug 2007 10:09:38 -0400


On 8/2/07, Craig D. Rice <cdr () stolaf edu> wrote:

We have already attempted the usual troubleshooting and have eliminated user
problems, computer problems, server problems, cable modem problems, and
Linksys router problems. Traceroutes have been somewhat inconclusive since
Onvoy blocks ICMP within its network.


Craig,

This rings a bell. Do they block the mandatory ICMP
fragmentation-needed messages?

Try this: on your web server, reduce the MTU from 1500 bytes to 1400
bytes and see if the affected comcast users can now access your web
server.

Regards,
Bill Herrin



-- 
William D. Herrin                  herrin () dirtside com  bill () herrin us
3005 Crane Dr.                        Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

Current thread:

I35 bridge collapse in Minneapolis Sean Donelan (Aug 01)
- Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy Craig D. Rice (Aug 02)
  - RE: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy Durand, Alain (Aug 02)
  - Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy William Herrin (Aug 02)
  - Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy Robert Boyle (Aug 02)
    - Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy Jim Shankland (Aug 02)
    - Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy Adrian Chadd (Aug 02)
    - Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy Jim Shankland (Aug 02)
    - Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy Valdis . Kletnieks (Aug 02)
    - Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy Duane Waddle (Aug 02)