Message-Id: 201604121045
Time: 14.04.2016, 6:00 pm – 6:30 pm
Affected: primary DNS and DHCP server gwdu01 / 134.76.10.46
Impact: Website of the GWDG (www.gwdg.de and info.gwdg.de) temporary not available and for about 5 to 10 minutes no DNS reply

On Thursday the 14.04.2016 the maintenance work on the primary DNS server for the GÖNET starting at 6:00 pm.

Therefore the websites www.gwdg.de and info.gwdg.de are for approximately 5 to 10 minutes not avialable. During this time no DNS reply and no DHCP leases are available in the most institutional and server networks including the guest net and the WLAN.

The second DNS server ns2.gwdg.de / 134.76.33.21 will not be affected.

Hints:
Please don’t change the DNS entry to ns2.gwdg.de permanently on your units. During the outage of the primary DNS server it is ok, but for the long run this server is not build for such a high durable load.

Please avoid rebooting your units during the maintenance window (6:00 pm to 6:30 pm), there will be no automatic IP adress allocation.

Backround:
The primary DNS and DHCP server gwdu01 is a cluster system consisting of two single servers. During the investigations on the sporadically appearing DNS issues in the last months, we found the underlying cause in the shared filesystem for both nodes. These issue we will solve on Thursday together with our support partner.

Due the fact that the second DNS server continuos operation, the network traffic should continue with minor troubles and timeouts.

We will do our best to shorten the downtime and apologize for any inconvenience.