One more time, I lost time thanks to a Microsoft issue…
With a colleague @ a remote office, we tried to setup a remote Sunray DTU as I did at home. Of course, we faced the fragmentation issue and started to find the best MTU value (thanks to tcpdump 😉 ).
We set the new value in the Microsoft DHCP server (option 26), rebooted the DTU, same issue, decreased the MTU, again and again… No way!
I googled a little bit and found this post on the Sunray-Users list:
There is a problem with windows DHCP servers not giving the MTU option
unless the devices specifically ask for it. Unfortunately the DTU’s
don’t specifically ask… This comes down to a difference in
interpreting the DHCP specification… I can’t remember who is really
right. The Solaris and Linux DHCP servers will give out all configured
options weather requested or not.
Source: http://www.filibeto.org/pipermail/sunray-users/2006-January/002521.html.