Technical data

Figure 9–4: Routing IPv6 Traffic from Host A to Host J
Host A Host B Host C
Host D Host E Host F
Host G Host H Host I
Department A
Department B
Department C
v4/v6 v4/v6 v4/v6
v4 v4 v4/v6
v4 v4 v4/v6
Router A
v4/v6
Router B
v4/v6
Router C
v4
VM-0953A-AI
Host J
6bone
Point of
Entry
Internet
To communicate with the 6bone, host A sends the IPv6 packet to router A. Router
A encapsulates the IPv6 packet and sends the IPv4 packet over a router-to-host
tunnel to the 6bone point of entry. The point of entry router decapsulates the IPv4
packet and routes the IPv6 packet to its destination.
9.3.3 Intranet-to-Internet-to-Intranet Scenario
In this scenario, you add v4/v6 routers on remote subnets and connect the two of
them through the Internet to create a virtual private network (VPN). An example
of this might be a global corporation with manufacturing in one country and a
design center in another country. The IPv6 hosts communicate with the v4/v6
routers using IPv6. For IPv6 traffic between the v4/v6 routers on each subnet,
you configure router-to-router tunnels.
Figure 9–5 illustrates a scenario in which the corporation described in the previous
sections wants to connect its corporate network with one of its geographically
remote departments to create a VPN.
To communicate with host K, host A sends the IPv6 packet to router A. Router A
encapsulates the IPv6 packet and sends the IPv4 packet over a router-to-router
tunnel to router E, which decapsulates the IPv4 packet and routes the IPv6 packet
to host K. For routers, the router-to-router tunnel is more efficient because the
router A administrator does not need to create individual router-to-host tunnels for
each destination host.
9–8 IPv6