[ale] MTU's and DSL's

[Keith R. Watson]

At 12:52 4/20/2005 -0400, you wrote:
>Does NAT impose some MTU changes? I just had to set the MTU on a web
>server down to 768 to get the traffic passing back out the firewall and
>up a Speakeasy DSL line.
>--
>James P. Kinney III          \Changing the mobile computing world/
>CEO & Director of Engineering \          one Linux user         /
>Local Net Solutions,LLC        \           at a time.          /
>770-493-8244                    \.___________________________./
>http://www.localnetsolutions.com
>
>GPG ID: 829C6CA7 James P. Kinney III (M.S. Physics)
><jkinney at localnetsolutions.com>
>Fingerprint = 3C9E 6366 54FC A3FE BA4D 0659 6190 ADC3 829C 6CA7


When the Linksys routers first came out I did some tests and found that 
PPPOE, VPN, and HTTPS caused the packet header to increase enough that the 
MTU had to be changed to compensate. Later versions on the Linksys firmware 
took care of this automatically. The MTU for the worst case scenario was 
1438. Something would appear to be wrong in Whoville if 768 is required.

keith

-- 

Keith R. Watson                        GTRI/ISD
Systems Support Specialist III         Georgia Tech Research Institute
keith.watson at gtri.gatech.edu           Atlanta, GA  30332-0816
404-894-0836