Ethernet NAPs

Thu Aug 23 13:34:00 UTC 2001

At 02:31 23/08/01, Mikael Abrahamsson wrote:
>...most vendors support at least 4470MTU on their GigE ports these days.

        True.

        As near as I can tell, nearly every vendor is supporting 
~9K MTU on GigE/10 GigE ports.  Not all of the vendors with ~9K MTU
support permit configuration of 4470 byte MTU -- a number of them 
have binary configuration knobs for ~1500 byte/~9K byte MTU, though 
clearly a number of vendors do permit configuration of a 4470 MTU.  
In some cases that configuration constraint might just be a software 
issue.  In other cases, there might be hardware issues.  The MTU size 
is related to certain other timer parameters and isn't really entirely 
an independent variable, btw.  Folks buying GigE interfaces might
want to investigate these factors as part of their product evaluations.

Ran
rja at inet.org