Help how change MTU size to 2048 value on WAN interface

From:	Giorgio Pellegrini <g dot pellegrini at cm dash amiata dot gr dot it>
To:	m0n0wall at lists dot m0n0 dot ch
Subject:	Help how change MTU size to 2048 value on WAN interface
Date:	Thu, 09 Feb 2006 11:49:10 +0100

Hello,
I need help to change MTU size to 2048 value on the WAN interface, but 
when I try  to do it by GUI interface I receive this error:

The following input errors were detected:

   * The MTU must be between 576 and 1500 bytes.

How could I resolve this problem?
Thank's in advance,
regards.
Giorgio Pellegrini