Step 1—Create the Host Table on YourCentral System

Use the CFGTCP command to configure your host table. Select option 10 (Work
with TCP/IP host table entries). Yoursystem’s host table is stored in member
HOSTS of file QATOCHOSTin library QUSRSYS.

Step 2—Start FTP to a Remote System

For example, if your host table defines the remote system as SYSNAM02, type the
FTP command as follows:
ftp sysnam02

Step 3—Tell FTP to Send the Host File to the Remote System

Type the following FTP subcommand:
put qusrsys/qatochost.hosts qusrsys/m03host.hosts
Note: Do not use FTP to put the host file directly into file QATOCHOSTcontaining
the AS/400 host table.

Step 4—Merge the File

Type the following FTP subcommand:
quote rcmd mrgtcpht fromfile(qusrsys/m03host) frommbr(host)
Domain Name System (DNS) Server
The conversion from host name to Internet address can be performed by using the
host table on the local system or by defining a Domain Name System server, or
DNS server.
In large networks with large host tables, it is more convenient to have DNS servers
than to have a complete copy of the host table on every host in the network. As a
single source for host names, a DNS server is capable of storing the name and
address translations for all of the computers on your network. The DNS server is
the preferred alternative to managing host tables.
This chapter does not document DNS server functions. However, if you are
interested in more detailed information about Domain Name System server (DNS)
support on your AS/400 and configuring a DNS server see “Chapter18. AS/400
Domain Name System (DNS)” on page421.
IP Routing and Internet Control Message Protocol (ICMP) Redirecting
Internet routing tables usually remain static for long periods. TCP/IP generates
routing tables at activation time from configuration data and adjusts the routing
tables based on ICMP redirects, SNMP manager requests, dead gateway
processing and socket routing requests.
If network interconnections change, routing tables in a particular host may become
incorrect. Because gateways exchange routing information periodically to
accommodate network changes and to keep their routes up to date, a gateway
usually knows better routes than a host. When a gateway detects that a host is
using a route that is not optimum, the gateway sends an ICMP redirect message to
76 OS/400 TCP/IPConfiguration and Reference V4R4