Information: Analysis of the network failure this morning

Message-Id: 202208071615
Time: Thu 7.7. 16:20 - 16:25, Fri 8.7. 8:12 - 9:30 and 8:12 - 14 (WiFi only)
Affected: GÖNET devices
Impact: Severe impairment of network connection and WiFi failure in some buildings until around 2 p.m.

Background:

Unfortunately there was a network overload on thursday around 04:20pm and again on friday around 08:15 am in many sites of the university, especially buildings that were (completely or partially) equipped with the ‘old’ WiFi access points (APs) of the company Juniper (formerly ‘Trapeze’). The cause was an extreme high data traffic from a central controller to multiple of these access points simultaneously, resulting in a very high data volume on the network devices along the path.

The exact cause of this misbehavior could not be traced so far.
However, early warning systems have been set up. Some changes were made in the configuration due to the data collected during the outage that presumably prevent this behavior.
The devices had been running for many years in identical configuration and are set up according to the best practices of the manufacturer and support partners.
However, we cannot completely exclude the possibility of a recurrence.

We apologize for the inconvenience caused.