[29209] in North American Network Operators' Group
RE: PMTU-D: remember, your load balancer is broken
daemon@ATHENA.MIT.EDU (Deepak Jain)
Wed Jun 14 19:35:23 2000
Date: Wed, 14 Jun 2000 18:46:28 -0400 (EDT)
From: Deepak Jain <deepak@ai.net>
To: jhsu@mur.com
Cc: nanog@merit.edu
In-Reply-To: <200006142214.SAA04073@rathe.mur.com>
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This can be done on FE interfaces too. Running Cisco FE interfaces
back-to-back at 4470 seems to work. I wanted to say that the GE interface
below doesn't work with large frames with a certain other vendor's
hardware the couple of times we've tried it, and that the default was in
fact 1500 for probably that reason.
One-off solutions tend to be more trouble than they are worth in big
networks.
Deepak Jain
AiNET
On Wed, 14 Jun 2000 jhsu@mur.com wrote:
>
> :
> : Then again, at least some Cisco gear doesn't think that.
> :
> : perdition>sh in g0/1
> : GigabitEthernet0/1 is up, line protocol is up
> : Hardware is Gigabit Ethernet, address is 00d0.7966.eeae (bia 00d0.7966.eeae)
> : MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, rely 255/255, load 24/255
>
> the last i checked, 1500 was the default. given the right hw & sw,
> MTU can be adjusted upward. i seem to remember seeing it demonstrated
> on 12000 gear.
>
> there is a draft [draft-kaplan-isis-ext-eth-02.txt] that discusses
> some extensions useful to support large frames. these extensions- again,
> the last i checked- were supported by cisco, and other vendors.
>
> as always, contact your authorized support rep when in doubt.
>
> ymmv,
>
> _k
>
>
