On Tue Sep 20 07:52:58 2016, Todd Goodman wrote:
> MTU is per network interface but you really don't want to end up having
> your router fragment every IP packet because systems on your subnet are
> using a larger MTU.
> 
> Todd

You will not fragment every packet, the PMTUd will do his job and will
lower all the next packets.

-- 
alarig