the specified port. If no match is found, the requesting program is not allowed to
use the specified port. If any port in the 1-1023 range is restricted, the following
message is posted:
Port restriction added but may affect TCP/IP processing
If no user profiles are associated with a specific port, there are no restrictions.
It is not necessary to configure port restrictions unless you are writing your own
TCP/IP applications and you want to reserve the use of the applications to certain
user profiles.
Note: For an installation in which user-written programs use ports other than the
well-known ports, you can consider restricting the use of the well-known
ports to the user profiles running the server application. As an example, for
File Transfer Protocol (FTP), this would be user profile QTCP.
Configuring TCP/IP Port Restrictions
Toconfigure TCP/IP port restrictions, type option 4 on the Configure TCP/IP menu.
The Work with TCP/IP Port Restrictions display is shown (Figure64).
Type option 1 (Add) at the input-capable top list entry to get to theAdd TCP/IP Port
Entry (ADDTCPPORT) display shown in Figure 65on page 87. You can go directly
to this display by typing ADDTCPPORTon any command line and pressing F4.
Work with TCP/IP Port Restrictions
System: SYSNAM03
Type options, press Enter.
1=Add 4=Remove
--Port Range--- User
Opt Lower Upper Protocol Profile
_ _____ *ONLY ____ __________
1050 1059 *TCP PAOLO
Bottom
F3=Exit F5=Refresh F6=Print list F12=Cancel F17=Top F18=Bottom
Figure 64. Work with TCP/IPPort Restrictions Display
86 OS/400 TCP/IPConfiguration and Reference V4R4