43.7.7. IPsec Network-to-Network Configuration

43.7.7. IPsec Network-to-Network Configuration

IPsec can also be configured to connect an entire network (such as a LAN or WAN) to a remote network using a network-to-network connection. A network-to-network connection requires the setup of IPsec routers on each side of the connecting networks to transparently process and route information from one node on a LAN to a node on a remote LAN. Figure 43.11, “A network-to-network IPsec tunneled connection” shows a network-to-network IPsec tunneled connection.

A network-to-network IPsec tunneled connection

A network-to-network IPsec tunneled connection

Figure 43.11. A network-to-network IPsec tunneled connection

This diagram shows two separate LANs separated by the Internet. These LANs use IPsec routers to authenticate and initiate a connection using a secure tunnel through the Internet. Packets that are intercepted in transit would require brute-force decryption in order to crack the cipher protecting the packets between these LANs. The process of communicating from one node in the 192.168.1.0/24 IP range to another in the 192.168.2.0/24 range is completely transparent to the nodes as the processing, encryption/decryption, and routing of the IPsec packets are completely handled by the IPsec router.

The information needed for a network-to-network connection include:


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