A virtual private network (VPN) allows your company to securely extend its private intranet over the existing framework of a public network, such as the Internet.
With VPN, your company can control network traffic while providing important security features such as authentication and data privacy. i5/OS™ VPN is an optionally-installable component of iSeries™ Navigator, the graphical user interface (GUI) for i5/OS. It allows you to create a secure end-to-end path between any combination of host and gateway. i5/OS VPN uses authentication methods, encryption algorithms, and other precautions to ensure that data sent between the two endpoints of its connection remains secure.
VPN runs on the network layer of the TCP/IP layered communications stack model. Specifically, VPN uses the IP Security Architecture (IPSec) open framework. IPSec provides base security functions for the Internet, as well as furnishes flexible building blocks from which you can create robust, secure virtual private networks. VPN also supports Layer 2 Tunnel Protocol (L2TP) VPN solutions. L2TP connections, which are also called virtual lines, provide cost-effective access for remote users by allowing a corporate network server to manage the IP addresses assigned to its remote users. Further, L2TP connections provide secure access to your system or network when you protect them with IPSec.
It is important that you understand the impact a VPN will have on your entire network. Proper planning and implementation are essential to your success. You should review the VPN topic in the iSeries Information Center to ensure that you know how VPNs work and how you might use them.