Overview of IPv6 Tunnels

For most enterprises, the introduction of IPv6 to an existing IPv4 network must occur on a gradual, step-by-step basis. The Solaris dual-stack network environment supports both IPv4 and IPv6 functionality. Because most networks use the IPv4 protocol, IPv6 networks currently require a way to communicate outside their borders. IPv6 networks use tunnels for this purpose.

In most IPv6 tunneling scenarios, the outbound IPv6 packet is encapsulated inside an IPv4 packet. The boundary router of the IPv6 network sets up a point-to-point tunnel over various IPv4 networks to the boundary router of the destination IPv6 network. The packet travels over the tunnel to the destination network's boundary router, which decapsulates the packet. Then, the router forwards the separate IPv6 packet to the destination node.

The Solaris IPv6 implementation supports the following tunneling scenarios:

• A manually configured tunnel between two IPv6 networks, over an IPv4 network. The IPv4 network can be the Internet or a local network within an enterprise.

• A manually configured tunnel between two IPv4 networks, over an IPv6 network, usually within an enterprise.

• A dynamically configured automatic 6to4 tunnel between two IPv6 networks, over an IPv4 network at an enterprise or over the Internet.

For detailed information about IPv6 tunnels, refer to IPv6 Tunnels. For information about IPv4- to-IPv4 tunnels and VPN, refer to Virtual Private Networks and IPsec.