Excuse me by asking somehow vague. Please let me be more precise: can anybody please explain me the networktraffic between sql-server and domain-controller on a installation following microsoft windows2008R2 recommendations (nothing weird like both servers on the same machine or other fancy setup)?
SnapOverflow
There is not a lot of traffic going on. Connections to the SQL Server made via Integrated Login will be performed the same way as a mapped drive would. The incoming connection details are sent to a domain-controller in the same AD Site as the SQL Server for validation before accepting a login request. This creates the security token for the incoming connection. Once connected, no further communication should be needed with the DC. Security comparisons are done against the ACL on the object versus the security principles listed on the generated token and is entirely local.
This is a very fast operation, though slowdowns can occur if one or more of the domain-controllers listed in DNS as being in the same AD Site as the SQL Server is not responding so the SQL Server has to time-out and attempt communications with the next one in the list.