IPv4/IPv6 over IPv6 GRE tunnels: Encapsulation and de-encapsulation

This feature enables IPv4 and IPv6 traffic to be transported through GRE tunnels over an IPv6 network. It supports both encapsulation and de-encapsulation of IPv4 and IPv6 payload packets. For encapsulation, the device adds GRE and outer IPv6 headers, and the tunnel destination can be resolved over IP, LDP, RSVP-TE, or LDP over RSVP-TE. For de-encapsulation, the device removes the outer IPv6 and GRE headers and forwards the original IPv4 or IPv6 payload toward its destination.