HuaWei ❀ GRE Encapsulation

A GRE

Generic Routing Encapsulation ProtocolGRE (Generic Routing Encapsulation) data packets to be certain network layer protocols (such as IPX, ATM, IPv6, AppleTalk, etc.) is encapsulated, so that the encapsulated data packets over another network layer protocol (e.g., IPv4) transmission. GRE provides a protocol packets encapsulated in the mechanism another protocol packets, is a three tunnel encapsulation technology, the GRE tunnel packet transmission may be through a transparent, heterogeneous network transmission problems.

GRE protocol packet format:

double same IP protocol header fields are the IP protocol field, according to the IP protocol parsing packet field;