MTU discovery

[The Nr Fairy]

Sorry to be a real geek, but does anyone out there know of a software tool which is standalone, runs on Windows 2000, and finds the lowest MTU in a routed path ?

It's for work !! I'm trying to find an answer on Tek-Tips but no joy so far.

[RomeoTangoFoxtrotMike]

Not all pretty and gooey, sorry, GUI ;) but how about using "ping" in a DOS window ?

Ping a host at the other end of the link under observation. Use the -l bufsiz option to set a max length buffer, and the -f "do not fragment" option to force it to maintain the packet size. Reduce the bufsiz until you don't get an error -- the bufsiz is then equal to MTU :ok:

Converting this to a small batch file for convenience is left as an exercise for the reader :)

[fobotcso]

This ought to do it (http://techupdate.zdnet.co.uk/story/0,,t507-s2123537,00.html)

[RomeoTangoFoxtrotMike]

I think that's what I said, isn't it ? :) It's alway's reassuring to find that somebody else agrees with you... ;)

[Ausatco]

Ummmm....

I'm not sure if this answers your original query, but it may be worthwhile looking here - iSpeed (http://www.hms.com/ispeed.asp)

There is an MTU discovery option in the prog.

I have used it to successfully tweak old dial-up connections and also my new ADSL connection. It's good stuff.

AA