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

[Brian E Carpenter <brc@zurich.ibm.com>]

Erik Nordmark wrote:
> 
> >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.

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

  Brian (now off-line until Jan. 5)