HP UX IPv6 Software manual Access to Payroll Application in the Main Office

Figure 7 illustrates the topology of the organization after setting up the new branch office and the required upgrades in the existing infrastructure.

Host A2				Host M1
Dual-stack Host A1					Host M2
Dual-stack Router A4	Router R2	IPv4 network	Router R1	Router M4	Dual-stack Host M3
Dual-stack Host A3
Host A5					Host M5

Host A6	Host M6
Branch A	Main office
	Dual-stack Router R3

Host B1	Host B2
	Router B3

Host B4

Host B5 Host B6

New branch B (IPv6 network)

Figure 7: Organization topology with new branch office

8.1 Access to Payroll Application in the Main Office

To enable employees in branch office B to access the payroll application running on server M3 in the main office, a router-to-host tunnel configuration can be used. A router–to-host configured tunnel is setup between router R3 and server M3. M3 is the endpoint for the tunnel from R3 to M3 and R3 is the endpoint for tunnel from M3 to R3.

The communication between hosts in branch office B and server M3 is described below:

1.A host in branch office B sends an IPv6 packet with server M3 as the destination address.

2.The router R3 receives the outgoing IPv6 packet. Based on the tunnel information, it encapsulates the IPv6 packet in an IPv4 packet with the source address set to IPv4 address of R3 and destination address set to the IPv4 address of server M3.

3.The encapsulated packet is forwarded to server M3 using the IPv4 routing infrastructure. When M3 receives the packet, it decapsulates it and since it is also the final destination of the IPv6 packet, it sends the packet up to the application.

4.When server M3 sends the response back, the IPv6 packet is encapsulated in IPv4 packet with the source address set to the IPv4 address of M3 and the destination address set to IPv4 address of R3.

5.The encapsulated packet is received by router R3. R3 decapsulates the packet and forwards the IPv6 packet to its final destination.

8.2 Access to Accounting Application in Branch Office A

To enable employees in the branch office B to access the accounting application running on server A1 and A3, a router-to-router tunnel configuration between router R3 and router A4 can be used. The router A4 is the endpoint for the tunnel from R3 to A4 and R3 is the endpoint for the tunnel from A4 to R3.

The communication between nodes in branch office B and server A1 and A3 happens as described in the previous section. The routers A4 and R3 will do the encapsulation and decapsulation.

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