This document describes how to configure TCP/IP on your AIX system. With AIX, you can configure your TCP/IP network with a single command, mktcpip. On other systems, setting up TCP/IP might involve creating and editing multiple files, executing a number of commands, setting various variables, locating values for persistence after reboot, and starting several daemons. The mktcpip command completes all the necessary TCP/IP configuration tasks for a typical system. The process is even easier when you use the System Management Interface Tool (SMIT) to prompt you for all necessary parameters to configure your network.
After you gather the prerequisite information, you can run the mktcpip command three ways: by using SMIT, the command line, or the Web-based System Manager.
AIX and related product documentation is also available:
Gather your network configuration information:
Configuring TCP/IP is easiest when you use SMIT. On the command line, enter the following fast path:
A dialog box requests which type of interface you plan to use. Then, SMIT builds a screen that lists each required value. After you fill in the fields with the network information that you have collected, the tool runs the mktcpip command in the background and makes the network available. Your task is finished.
If you prefer the command line approach, you can specify all the necessary parameters in a single instruction, as shown in the following example:
mktcpip -h server1 -a 10.47.1.3 -m 255.255.0.0 -i en0 \ -n 18.104.22.168 -d itsc.austin.ibm.com -g 22.214.171.124 -s -C 0 -A no
If you prefer a more graphical interface, you can use the Web-based System Manager tool to complete this task. This tool uses icons, windows, and wizards to guide you through the configuration. To start this interface, enter the following on the command line:
No matter which method you choose, online help is available to assist you. For example, to access online help within SMIT, use the F1 key.
If you want to further configure your network, for example, if you want to select more than one interface type, SMIT has an easy interface for that, too. On the command line, enter:
Customizing your TCP/IP configuration beyond the minimal configuration is easily done through SMIT, the command line, or the Web-based System Manager. SMIT menus guide you through such tasks as:
When you install AIX, it automatically detects each adapter card and installs the corresponding interface software. AIX uses the following naming convention for network devices and interfaces:
Device Type Device Name Interface Name
Asynchronous Transfer Mode (ATM) atm# at#
Ethernet (IEEE 802.3)   ent# et#
Ethernet (Standard, Version 2) ent# en#
Fiber Distributed Data Interface (FDDI) fddi# fi#
Loopback N/A lo#
Token-ring tok# tr#
If you use name services, you can provide the minimal information needed through the mktcpip command. Typically, the /etc/resolv.conf file stores your domain name and name server IP address. The mktcpip command creates or updates the /etc/resolv.conf file for you. By default, the resolver routines on hosts running TCP/IP use the following lookup sequence:
But you can override the default lookup by editing the /etc/netsvc.conf file. (See the AIX Files Reference for details.) Also, you can set the NSORDER environment variable to override the host settings in the /etc/netsvc.conf file.
A machine can communicate to the network through a gateway. A gateway contains the addressing and routing information for each host on its network, and can use routing daemons to broadcast routing information to, and receive routing information from, other gateways. TCP/IP routes information to the appropriate computer on the network using address information carried in a packet or stream of information.
AIX version 5.0 allows a host to discover if one of its gateways is down (called dead gateway detection) and, if so, choose a backup gateway, if one has been configured. Dead gateway detection can be passive (the default) or active.
In either mode, the host chooses the alternate gateway with the lowest associated cost value. You determine the cost value, using any criteria you wish, when configuring TCP/IP. The value can be any number from 0 (the default) to 2147482647.
The mktcpip command can do much more than minimal TCP/IP configuration. The following table defines all the flags available for the mktcpip command.
The following is the standard format for setting the host name in a domain naming system:
The mktcpip command runs a shell script called rc.tcpip to start the TCP/IP daemons for your configuration. The script contains start stanzas for the following daemons:
By default, the script starts the syslogd, portmap, inetd, lpd, and sendmail daemons and puts their entries into the /etc/inittab file so the subsystems begin automatically after every reboot. To automatically start any of the other listed daemons, simply uncomment their corresponding lines in the rc.tcpip file. You can add start stanzas for other daemons, too.
[ Doc Ref: 98199831211382 Publish Date: Apr. 06, 2001 4FAX Ref: 1042 ]