[38217] in North American Network Operators' Group
RE: jumbo frames
daemon@ATHENA.MIT.EDU (RJ Atkinson)
Thu May 31 17:48:47 2001
Message-Id: <5.1.0.14.2.20010531174107.00aa53d0@10.30.15.2>
Date: Thu, 31 May 2001 17:43:40 -0400
To: Mikael Abrahamsson <swmike@swm.pp.se>
From: RJ Atkinson <rja@inet.org>
Cc: <nanog@merit.edu>
In-Reply-To: <Pine.LNX.4.33.0105312254450.853-100000@uplift.swm.pp.se>
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Errors-To: owner-nanog-outgoing@merit.edu
At 16:58 31/05/01, Mikael Abrahamsson wrote:
>Too bad ciscos 3GE card only supports 2450 MTU. The 1GE supports 9180 and
>the PA-GE supports 4470. Oh joy, pick a standard, glad there are so many
>to choose from.
For those non-oldtimers:
4470 == FDDI MTU
9180 == ATM AAL5 IP MTU (RFC-1626)
Off hand, 2450 sounds like someone forgot to put enough RAM
on the card when doing the board design and that is what they
could actually support when the board appeared. Sigh.
>It seems more newer L2 GE-switch manufacutrers support jumbo (real jumbo,
>up to at least 8192, most of them even higher) than the older router
>manufacturers (or is it just cisco?).
Mostly cisco has had trouble getting with the Jumbo MTU program,
though occasionally they do something reasonable. Most non-cisco
GigE products are engineered to support the 9180 IP MTU (RFC-1626).
Ran
rja@inet.org
