Subject: RE: [Pppext] Re: Last Call: 'Accommodating an MTU/MRU greater than1492 in PPPoE' to Informational RFC

From: "Veera Tubati \(vtubati\)" <[email-masked]>
Date: Sun, 19 Feb 2006 23:08:39 -0800

I wonder if draft should state its position about IPCP start while 
MRU test is enabled.

I would think IPCP start should be delayed (if this verification option
is enabled) till verification is finished and BRAS decides on MTU to be
used. Else, if there is a TCP session coming in soon after IPCP is up
and if verification process reduces the MTU later down to 1492 that TCP
session would be using a wrong MTU and would have connectivity problems.

Veera

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From: James Carlson <[email-masked]>
Date: Mon, 20 Feb 2006 13:37:54 -0500

> session would be using a wrong MTU and would have connectivity problems.

I don't see how that'd be helpful.

If the MTU negotiated at LCP time later turns out to be a problem,
you're going to need to restart LCP anyway, and that will tear down
IPCP.  So how does waiting help?  At best it avoids a small bounce (IP
goes up briefly, then down and back up again) in an unusual error
case.

And it's something that could be handled in a decent implementation by
keeping track of the MAC address of the peer and remember the MTU
limit.

-- 
James Carlson, KISS Network                    <[email-masked]>
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