Methods, systems, and apparatus are described for network encapsulation and routing. In one aspect, a method includes receiving, from source network and at an edge device a first network packet including a first inner header including i) a first source address, and ii) a first destination address; selecting a source network identifier for the source network from a plurality of routable network identifiers; encapsulating the first network packet within a first encapsulation packet; routing the first encapsulation packet to the destination server; receiving, from the destination server, a second encapsulation packet; extracting the second network packet from the second encapsulation packet; and routing the second network packet to the source network.