MIME-Version: 1.0
In-Reply-To: <alpine.LSU.2.00.1603101227280.22844@hermes-2.csi.cam.ac.uk>
X-Mailer: MIME-tools 5.505 (Entity 5.505)
Content-Disposition: inline
X-RT-Interface: Web
References: <alpine.LSU.2.00.1603101227280.22844@hermes-2.csi.cam.ac.uk>
 <RT-Ticket-41908@isc.org>
Content-Type: text/plain; charset="utf-8"
Message-ID: <rt-4.2.8-31497-1457615793-261.41908-0-0@isc.org>
Content-Transfer-Encoding: binary
X-RT-Original-Encoding: utf-8
RT-Send-CC:
X-RT-Encrypt: 0
X-RT-Sign: 0
Content-Length: 485

There are a lot of articles about TCP sockets
waiting in TIME_WAIT. I believe I read the first
on 30 years ago...
The problem is not in applications but in the kernel.
BTW as you use Linux there are some specific tunings
which solve it.

About to add a REUSEADDR it has a bad side effect
as some traffic not for dig or named can be caught
by accident: REUSEADDR explicitly allows port
collision... And we got complains about this issue
when named used this socket option without care.