Understanding IPv6 over IPv4 tunnel

IPv6 over IPv4 Manual Tunnel

An IPv6 over IPv4 manual tunnel is manually created and configured on the border routers on both ends of the tunnel. To configure this tunnel, you must specify static source and destination IPv4 addresses.

IPv6 over IPv4 GRE Tunnel

An IPv6 over IPv4 GRE tunnel is also manually created and configured on border routers on both ends of the tunnel. However, you can configure checksum on GRE packets and verification on tunnel keywords to enhance tunnel security.

IPv6 over IPv4 Automatic Tunnel

An IPv6 over IPv4 automatic tunnel uses an IPv4-compatible IPv6 address and applies only to the communication between IPv6 sites.

6to4 Tunnel

A 6to4 tunnel connects multiple IPv6 islands over IPv4 networks. Similar to the IPv6 over IPv4 automatic tunnel, the 6to4 tunnel requires only the source. The tunnel destination is automatically generated by the device. The 6to4 tunnel requires 6to4 addresses.

6RD Tunnel

The IPv6 Rapid Deployment (6RD) tunneling technology is based on the existing IPv4 network. It helps users to deploy the IPv6 access service rapidly.

ISATAP Tunnel

Defined in RFC4214 as an IPv6 automatic tunnel, the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) tunnel is used by the dual-stack host on an IPv4 network to access the IPv6 network.