Abstract: A router node comprises a link discovery module, a security module, a secure access module and storage. The link discovery module discovers a link to an adjacent router node and receives its first loopback address. The link discovery module creates a first tunnel between the security module in the router node and the first loopback address. The security module receives a second loopback address for the second router node, and creates a second tunnel. The security module repeats the discovering, receiving and creating steps for each router node adjacent to the first router node. The storage separately stores a link discovery routing table which comprises information relating to the links between the router node and each adjacent router note; a security routing table which stores the unique first loopback address; and a secure access routing table which stores the unique second loopback address.