If you have CA/400 or CA/Express, use the TCP/IP Interface Wizard. (Copied from IBM's site, Configuring TCP/IP) To use the TCP/IP Interface Wizard to configure TCP/IP on your iSeries for the first time, follow these steps:
1. In Operations Navigator, expand your iSeries server --> Network --> Protocols. 2. In the right pane, right-click TCP/IP and select New Interface. 3. From here, select Local Area Network, Wide Area Network, or Virtual IP to open the appropriate TCP/IP Interface Wizard. Follow the wizard's instructions to configure your TCP/IP interface.
If you do not have CA/400 or CA/Express, use the OS/400 TCP/IP Configuration and Reference in the AS/400 Library.