[67230] in North American Network Operators' Group
Re: MTUs - Was: Strange public traceroutes return private RFC1918addresses
daemon@ATHENA.MIT.EDU (sthaug@nethelp.no)
Thu Feb 5 15:40:50 2004
To: warren@kumari.net
Cc: nanog@merit.edu
From: sthaug@nethelp.no
In-Reply-To: Your message of "Thu, 5 Feb 2004 15:04:00 -0500"
Date: Thu, 05 Feb 2004 21:34:29 +0100
Errors-To: owner-nanog-outgoing@merit.edu
> Why is the MTU on Ethernet 1500 bytes? I have looked through various
> docs (eg IEEE Std 802.x) and can find where maxUntaggedFrameSize is
> listed as 1518 octets, but there is no mention of why this was chosen.
> I know where the minimum frame size comes from (CSMA/CD and propagation
> times, etc), but the maximum frame size number sounds fairly arbitrary.
I believe Rich Seifert once said (on comp.dcom.lans.ethernet) that the
cost of the necessary buffer memory for the first Ethernet cards was a
relevant factor.
Steinar Haug, Nethelp consulting, sthaug@nethelp.no
