Subject: Re: TCP checksum not good enough?
To: Andy Ruhl <acruhl@gmail.com>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: netbsd-users
Date: 08/02/2006 16:28:41
On Wed, Aug 02, 2006 at 01:20:38PM -0700, Andy Ruhl wrote:
> Hello all. This may come across as a troll type post, but I don't mean
> it to be. Nor am I trying to stir anything up.
> 
> I came across a problem at work today that I've never seen before, but
> apparently it exists because I searched on it and I got some rather
> disturbing hits.
> 
> A very large database was being backed up over a TCP/IP network, and
> the restore of it to a test system would often be corrupt. This
> prompted some very heated conversations, let's say.
> 
> The backup application involved had a checksumming feature on the
> payload of the data, and when this was turned on an error was found.
> 
> Which means this data passed through whatever hardware checking was
> done (not known to me exactly what, if any, there is) AND TCP
> checksumming.

How do you know the data were not corrupted after the TCP checksum was
performed?

Thor