The University of Münster doesn’t have a centralised campus but its buildings are spread out throughout the whole city centre. Thus the network is more like a metropolitan area network (MAN) than just a simple LAN. Several areas are equipped with a set of access switches that connect to the central core routers UNIA and UNIB. Reliability is provided by running the HSRP protocol between the routers.

VLANs are not necessarily limited to a single area but may span several access router located elsewhere.

Next to the core network of the university the ZIV manages a similar core network for the clinical facilities which is organised likewise (see the right side of Figure 13-1). Other sites connected to the transit routers are the Fachhochschule Münster and soon the Max-Planck-Institute. Other site networks may follow later on.

The scenario described here is an ideal one. As the University has quite a lot of areas, it is not affordable to allocate two high end routers to every location. To realise the described infrastructure we use virtualised router technology. (The reason for this extended virtualization is to create a hierarchical routing structure. This allows a strict correlation between a double set of routers and an area/site, which allows defining a security infrastructure and limits access based on the fact where a node is located in the network).

In addition, not every building is connected via this newer network infrastructure. There still exist remnants of old technologies used in the past, namely an ATM network and even some last parts of an FDDI ring. Some far off site buildings use ISDN or DSL to connect to the University’s network.

Of course the management of this network is quite sophisticated. The most important components are Tivoli Netview management, an Oracle Database which contains every router, host, cable, number and data that is used for this network, and a web-based front-end system to update information in this database easily.