The present invention extends to methods, systems, and computer program products for routing using global address pairs. Embodiments of the invention use publicly routable Internet Protocol (“IP”) addresses to represent sites rather than individual hosts. Hosts can be represented by a global address pair, including site public IP address and a node private IP address. Nodes route packets to address processing modules using IP-in-IP encapsulation. An outer header contains a site public IP address and is destined to a site on inter-site links. An inner header contains a node private IP address and is destined to a private endpoint in intra-site links. In some embodiments, a site public IPv4 address and a node private IPv4 address are encoded into an IPv6 address. Use of an IPv6 address makes encoding of the two IPv4 address transparent to IPv6 applications.