US Patent 8964767 Packet processing in federated network

Some embodiments provide a novel method for forwarding a packet at a managed switching element in a first domain. The method receives a packet from a local machine. The method encapsulates the packet with a first context identifier that identifies a first logical port of a first logical switching element that couples to machines in both the first domain and a second domain. The first logical port maps to a destination address of the packet. Based on a mapping of the first logical port to a second logical port of a second logical switching element that couples to machines in only the first domain, the method encapsulates the packet with a second context identifier that identifies the second logical port. The method transmits the twice-encapsulated packet out of a port of the managed switching element based on the second context identifier.