The embodiments of the present invention disclose a method for processing a packet and a related device. One implementation consists of a method for processing a packet that comprises receiving, by a first network device, a forwarded packet, performing a flow table matching for the forwarded packet, and if unmatched, encapsulating the forwarded packet with an inner encapsulation and an outer encapsulation, and transmitting the forwarded packet to a second network device. The method further comprises receiving a flow table packet returned by the second network device, wherein the flow table packet carries flow table information of the forwarded packet and is encapsulated with a special layer 2 frame header, and processing the flow table packet according to an operation indicated by an Ethernet type value in the special layer 2 frame header.