Um, *I* can set the MTU on my ethernet interfaces (except an ne2 PCIMCIA
card in my laptop).  On the ne2, I can do a ``route change default -mtu
...'' however, which seems to work just about as well.  (You might not be
able to set them larger than 1500, but you should be able to set them
smaller.)  As I understand it, ethernet is *not* using fixed-sized frames,
so setting a lower MTU is entirely possible.  It might not work if the
driver, or card, don't choose to support it---though the route command
should still always work to force a lower effective MTU.

(I needed to drop the MTU on Internet communications through ipnat on my
gateway.  With default MTU's, connections sending large blocks tend to
stall.)


  ``I probably don't know what I'm talking about.'' --rauch@math.rice.edu