nanog mailing list archives
Re: mtu mis-match
From: Greg VILLAIN <nanog () grrrrreg net>
Date: Thu, 20 Mar 2008 10:29:19 +0100
On Mar 19, 2008, at 8:05 PM, ann kok wrote:
Hi I have this problem about mtu mismatch Some DSL clients, some are working fine. (browsing...ping ...) Some DSL clients have this problem they can't browse the sites. they can ssh the host but couldn't run the command in the shell prompt ping packet are working fine (no packet lost) Why? but I still don't know why mtu can cause this problem Thank you for your help
Sounds like the old PPPoE issue : 1500 vs 1492. It usually is dealt with on a per destination basis:For a given destination (the ones that are causing problems to you) start with : ping -D -s 1500 <your_destination> and lower the -s value until the ping goes through.
-D forces "don't fragment bit" -s manages packetsizeWhen your ping reaches your destination, your -s size is good (for that destination only...).
Greg VILLAIN Independent Network & Telco Architecture Consultant Greg VILLAIN Independant Network & Telco Architecture Consultant +33 6 87 48 66 14
Current thread:
- mtu mis-match ann kok (Mar 19)
- Re: mtu mis-match Jon R. Kibler (Mar 19)
- Re: mtu mis-match Justin M. Streiner (Mar 19)
- Re: mtu mis-match Pekka Savola (Mar 20)
- Re: mtu mis-match Greg VILLAIN (Mar 20)
- Re: mtu mis-match Rich Kulawiec (Mar 20)
- Re: mtu mis-match Michael Holstein (Mar 20)