How to determine maximum MTU
 

I have some funny business going on in my router. I once read (a long time ago) about a way to determine the maximum MTU value that your connection could handle before fragmenting. Does anybody know where I could find a how to on that subject?

a quick serach on google (searched for maximum mtu) brought to me to this page http://www.erg.abdn.ac.uk/users/gorr...pages/mtu.html
this a decent explanation of how it could be done

basically set the mtu to be the highest for your connection then set the don't fragment flag on the packet. If the packet needs to be fragmented you will get an ICMP reply, destination unbreachable - Fragmentation Needed and Don't Fragment was Set

Excellent!! -it's bookmarked. Thanks Sutekh.

normally 1500, shows up in ifconfig

That is the case for me as well. I wanted to do a little experimenting as I see there is quite a bit involved here. I had to put that project on hold for now though as I am changing router distros.