HP UX IPv6 Software 5.2 Router-to-Router, 5.3 Host-to-Routerand Router-to-Host

IPv4 host	IP6-in-IP tunnel	IPv4 host
		IPv4 network
	IPv4 Router	IPv4 Router
IPv6/IPv4 host		IPv6/IPv4 host

Figure 2: host-to-host tunnel configuration

IPv4 host

5.2 Router-to-Router

In a router-to-router tunnel configuration, IPv6/IPv4 routers interconnected by an IPv4 infrastructure can tunnel IPv6 packets between themselves. In this case, the tunnel spans one segment of the end-to-end path the packet takes.

IP6-in-IP tunnel
IPv6 host		IPv6 host
IPv6/IPv4 Router	IPv4 network	IPv6/IPv4 Router

IPv6 host

IPv6 host

Figure 3: router-to-router tunnel configuration

IPv6 host

The router-to-router tunnel configuration is useful to connect two IPv6 domains separated by IPv4 network.

5.3 Host-to-Router and Router-to-Host

In a host-to-router configuration, the tunnel spans the first segment of the packet’s end-to-end path. In the router-to-host configuration, the tunnel spans the last segment of the packet’s end-to-end path.

The host-to-router and router-to-host tunnel configuration is useful when a whole site needs access to a service running on a dual stack host in an IPv4 network.

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