Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 4 Jul 2000 15:39:14 +1200
From:      Joerg Micheel <joerg@cs.waikato.ac.nz>
To:        David Gilbert <dgilbert@velocet.ca>
Cc:        freebsd-stable@FreeBSD.ORG
Subject:   Re: Ethernet MTUs > 1500?
Message-ID:  <20000704153914.C60136@cs.waikato.ac.nz>
In-Reply-To: <14689.22689.894466.908666@trooper.velocet.net>; from dgilbert@velocet.ca on Mon, Jul 03, 2000 at 11:23:13PM -0400
References:  <14689.22689.894466.908666@trooper.velocet.net>

next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jul 03, 2000 at 11:23:13PM -0400, David Gilbert wrote:
> But a number of devices seem to allow for MTUs > 1500 on 100Mb
> ethernet... and several people have told me that the standard allows
> for packets bigger than 1500 bytes.

The limit is 1536. That is hex 0x600, a value of importance if using
802.x networks. A value below 0x600  indicates the length of an additional
header in the EtherType field. If this value is above 0x600 it indicates a
certain protocol (such as 0x800 for IP, 0x806 for IP ARP).

I would not twiddle with the settings, the extra gain is very low and
you'll face all sorts of compatibility issues with devices not supporting
it.

	Joerg
-- 
Joerg B. Micheel			Email: <joerg@cs.waikato.ac.nz>
Waikato Applied Network Dynamics 	Phone: +64 7 8384794
The University of Waikato, CompScience	Fax:   +64 7 8585095
Private Bag 3105			Pager: +64 868 38222
Hamilton, New Zealand			Plan:  TINE and the DAG's


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000704153914.C60136>