Overview of IPv6 GREIPv6 Generic Routing Encapsulation (GRE) encapsulates the packets of certain network layer protocols so that the encapsulated packets can be transmitted over the IPv6 network.

IPv6 Generic Routing Encapsulation (GRE) encapsulates the packets of certain network layer protocols so that the encapsulated packets can be transmitted over the IPv6 network.

IPv6 GRE provides a mechanism of encapsulating packets of a protocol into packets of another protocol. This allows packets to be transmitted over heterogeneous networks. The channel for transmitting heterogeneous packets is called a tunnel. A tunnel can be viewed as a virtual interface that supports only P2P connections. The tunnel interface provides a tunnel for data forwarding. A tunnel encapsulates packets at one end and decapsulates packets at the other end.

IPv6 GRE can also serve as a Layer 3 tunnel protocol and provides a tunnel for transparently transmitting VPN data.

Currently, an IPv6 GRE tunnel can encapsulate and route only IPv4 and IPv6 packets.