[3486] in linux-net channel archive
Re: Speaking of MTU problems
daemon@ATHENA.MIT.EDU (Alan Cox)
Tue Jun 25 08:51:41 1996
From: iialan@iifeak.swan.ac.uk (Alan Cox)
To: dennis@etinc.com (Dennis)
Date: Mon, 24 Jun 1996 19:03:20 +0100 (BST)
Cc: linux-net@vger.rutgers.edu
In-Reply-To: <199606241412.KAA16580@etinc.com> from "Dennis" at Jun 24, 96 10:12:41 am
> Shouldn't the (physical) mtu of a device take into account to header
> length? I noticed in 1.2.13 that sometimes it does, and sometimes
> it doesn't ie if the MTU is 1500 and the hard_header_len is defined as,
> say 16, sometimes it will send 1484 bytes of data to the device, and
> others (specifically when generated internally, as with a PING packet)
> it will send the full MTU when fragmenting. It caused a nasty bug a
> while back when our buffer size was only the MTU size...much crashing
> occurred :(
Known 1.2 bug. Fixed in 2.0. MTU is always the size of the carried data not
including device overheads like MAC headers
Alan
