Subject: Re: [Fwd: I-D ACTION:draft-lear-multi6-things-to-think-about-00.txt]

From: Erik Nordmark <[email-masked]>
Date: Fri, 19 Dec 2003 12:55:01 -0800

>With any multihoming solution that allows rewriting of addresses 
>between the moment the checksum calculation is done and the moment the 
>packet is transmitted/received, checksum offloading will pretty much 
>have to be a thing of the past, unless we want to start doing some 
>complex incremental updating in different places.

I think whether checksum offloading is affected or not is a function of 
exactly how checksum offloading is implemented.

I know one vendors implementation of checksum offload that wouldn't have
a problem - because software is capable of compensating for differences
between the IP addresses in the IP header and in the TCP pseudo-header
in order to properly handling routing headers.

I don't know to what extent the same flexibility exist for other vendors.

  Erik

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From: Brian E Carpenter <[email-masked]>
Date: Sun, 21 Dec 2003 11:28:03 +0100

> I don't know to what extent the same flexibility exist for other vendors.

Indeed, it is undesirable to rely on product kludges in an architecture.

  Brian (now off-line until Jan. 5)