Building the Network Infrastructure for the International Mathematics Olympiad

In this paper we describe the network infrastructure we designed, built and operated for the International Mathematics Olympiad in the Netherlands in 2011. The infrastructure was pragmatically designed around OpenVPN tunnels in a star topology between the various venues. VLANs were extensively used to separate functional groups and networks. The actual construction of the event network took about 3 days and was needed for only 2 weeks. The architectural, setup, building and operational aspects of the network are described and we include some lessons learned.