Encoding control plane information in transport protocol source port field and applications thereof in network virtualization

摘要

A novel method that uses the source port field in the transport or connection layer (L4) header to encode control plane information is provided. Specifically, the method encodes control plane information in UDP or TCP source port field of data plane tunnels in an overlay network such as VXLAN. Network virtualization is implemented by a network controller over an overlay network on the physical fabric. The network controller provides a mapping table to the data plane hosts for mapping the encoded bits in the source port field to semantically richer information. The data plane hosts in turn uses the encoded source bits and the mapping table to infer this semantically richer information. This semantically richer information is used to allow receivers of proxied traffic to learn the address of the original sender. The semantically richer information can also be used to enable ECMP for the transmitted packets.

主权项

1. A method for forwarding packets in an overlay logical network, each packet comprising a L4 source port field, a L4 destination port field, a L3 source address field, and a L3 destination address field, the method comprising:
receiving a mapping table for encoding L3 IP addresses into identifiers to be stored in the L4 source port fields of the packets; receiving, at a first tunnel endpoint, a first packet from a second tunnel endpoint in an overlay logical network, the first packet storing an IP address of the second tunnel endpoint in the L3 source address field of the first packet and an identifier of an original sender in the L4 source port field of the first packet, the original sender being different than the second tunnel endpoint; identifying the original sender of the first packet by using the received mapping table to extract the IP address of the original sender from the identifier stored in the L4 source port field of the first packet; and transmitting a second packet to the identified original sender of the first packet by using the decoded IP address of the original sender.