IBM AS/400e Computer Hardware User Manual


 
even some small organizations that access the Internet require a DNS server to
meet their name-service needs. See “Chapter 18. AS/400 Domain Name System
(DNS)” on page 421 for more information.
Managing TCP/IP Host Tables
In a large network, it can be more efficient to administer AS/400 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.
AS/400 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 AS/400
host table:
v Host table type *AS400, generated by AS/400 TCP/IP Version 3 Release 1
Modification 0 (V3R1M0) or later
v Host table type *AIX, generated by AS/400 TCP/IP Version 3 Release 0
Modification .5 (V3R0M5), Version 2 Release 3 (V2R3) or earlier, or many other
IBM and non-IBM systems
v Host table type *NIC, host table format used by public domain systems
You can merge or replace the local AS/400 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 AS/400 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 5 shows the *AIX format supported on the AS/400 system.
Table 5. *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.
Chapter 3. TCP/IP: Operation, Management, and Advanced Topics 73