> Anyway, I knew this had to be an mtu issue but the usual setting it to
> 1492 just didn't work  ... after some trial and error,


1492 is mtu of pppoe encapsulated connections; vpn tunnels surely add more
overhead, depending on level of encapsulation.

Also, there is an issue also related to monowall (freebsd) when used with
dummynet regarding generation of ICMP fragmentation packets.
Look at the list archives for more information.



.FT