Managing TCP/IP Host Tables
In a large network, it can be more efficient to administer iSeries TCP/IP from a central site. Working with the host table would be time consuming if each system is individually updated with the TCP/IP configuration menu. Updates can be made more quickly on one system and then copied to others.
iSeries TCP/IP is designed to protect configuration files, including the host table. You cannot change the host table file unless you use the Configure TCP/IP menu or the MRGTCPHT, ADDTCPHTE, RNMTCPHTE, CHGTCPHTE, or RMVTCPHTE commands. However, you can still import and use a host table from a central site by using the MRGTCPHT command.
The following host table file types can be imported and merged with the server host table:
vHost table type *AS400, generated by iSeries TCP/IP Version 3 Release 1 Modification 0 (V3R1M0) or later
vHost table type *AIX, generated by iSeries TCP/IP Version 3 Release 0 Modification .5 (V3R0M5), Version 2 Release 3 (V2R3) or earlier, or many other IBM and
vHost table type *NIC, host table format used by public domain systems
You can merge or replace the local server host table with the imported host table. The name of the database file containing the local host table is QATOCHOST with member HOSTS in library QUSRSYS. This file is used directly by iSeries TCP/IP; no conversion into an internal version takes place.
Host File Formats
If you receive a host file and want to use it on your system, the MRGTCPHT (Merge TCP/IP Host Table) command allows you to specify which format you are using. You can use host information files that are in either the *NIC format, the *AIX format, or the *AS400 format. The record length of the imported host table file is not limited.
Host Table Information with *AIX Files
Table 4 shows the *AIX format supported on the server.
Table 4. *AIX Supported on the AS/400 System
Delimiter | Meaning |
|
|
# (pound sign) | Indicates the beginning of a comment. The text |
| following the pound sign is a comment and is not part |
| of the host table. |
|
|
blank, tab | Indicates a field delimiter. |
|
|
Host Table Information with *NIC Files
The *NIC format is often used by hosts in the public domain. A record in a *NIC file has the following format:
HOST : 128.12.19.1 : Host2.lan.ibm.com,Host2 :
This entry describes one host (at address 128.12.19.1) with two names (Host2.lan.ibm.com) and (Host2). The host is an IBM Personal Computer AT® computer running
Chapter 2. TCP/IP: Operation, Management, and Advanced Topics 51
