Virtual private networks and IP security

A virtual private network (VPN) securely extends a private intranet across a public network such as the Internet.

VPNs convey information across what is essentially a private tunnel through the Internet to and from remote users, branch offices, and business partners/suppliers. Companies can opt for Internet access through Internet service providers (ISPs) using direct lines or local telephone numbers and eliminate more expensive leased lines, long-distance calls, and toll-free telephone numbers. A VPN solution can use the IPsec security standard because IPsec is the IETF-chosen industry standard network security framework for both the IP Version 4 and 6 environments, and no changes are needed for existing applications.

A recommended resource for planning the implementation of a VPN in the AIX® operating system is Chapter 9 of A Comprehensive Guide to Virtual Private Networks, Volume III: Cross-Platform Key and Policy Management, ISBN SG24-5309-00. This guide is also available on the Internet World Wide Web at http://www.redbooks.ibm.com/redbooks/SG245309.html.