Thoughts on increasing MTUs on the internet

Fri Apr 13 16:24:26 UTC 2007

On Fri, Apr 13, 2007, Steve Meuse wrote:
> On 4/13/07, Valdis.Kletnieks at vt.edu <Valdis.Kletnieks at vt.edu> wrote:
> >
> >
> >For that matter, what releases of Windows support setting a 9K
> >MTU?  That's
> >probably the *real* uptake limiter.
> 
> Most, if not all.  I have an XP box that has a GigE with 9k MTU.

Lucky you. The definition of "large frames" varies depending entirely
upon driver. I came up against this when a client nicely asked about
jumbo frames on his shiny new Cisco 3560 switch - and none of his
computers could agree on anything greater than 4k. And, to make things
worse - a few of the drivers wanted to enforce certain values rather
than any value between 1500 and an upper limit - making the whole
feat impossible.

Yay for non-clear specifications. The skeptic in me says "ain't going
to happen." The believer in me says "Ah, that'd be cool, wouldn't it?"
The realist in me says "probably best to mandate that kind of stuff
with the next revision of the ipv6-internet with the first few bits
set to 010 instead of 001. :)

The real uptake limiter is the disagreement on implementation.
Some of you have to remember how this whole internet thing started
and grew (I've only read about the collaboration in books.)

Adrian