IBM AS/400e Computer Hardware User Manual


 
SMTP, if configured
POP
WSG
LPD
REXEC
HTTP
Passive listening connections have an asterisk in the
Remote Address
and
Remote Port
fields. Ending these connections is not recommended. Remote
systems cannot use SNMP, FTP or TELNET, send SMTP mail to the local
system, or send spooled files using LPR to the local system if the associated
passive listening connections have been ended. They can be restarted by
ending and starting the servers using the ENDTCPSVR and STRTCPSVR commands
and then specifying the server you want ended and started.
3. Ensure that the ports associated with the application you are attempting to use
are not restricted. Use option 4 (Work with TCP/IP port restrictions) from the
Configure TCP/IP menu to view the current port restrictions.
Cause List E
Verify the configuration data. If everything checks out, go to the flow chart for the
particular application that you are using.
PING Command Considerations
The following sections discuss how the AS/400 system concatenates the domain
name to the host name and examples are given for some of the most common
PING error conditions.
Concatenating the Domain Name to the Host Name
This example illustrates how the AS/400 system concatenates the domain name to
the host name if a period is not used at the end of the domain name.
Your AS/400 system name is SYSNAM01.A400SSC.DFW.COMPANY.COM, and you
want to verify the connection to a system whose full name is
SYSNAM02.DFW.COMPANY.COM. Your remote name server is configured to return
the address for SYSNAM02.DFW.COMPANY.COM if you send the name server
either the full name (SYSNAM02.DFW.COMPANY.COM) or just the short name
(SYSNAM02). You do not have a SYSNAM02 host name in your local host table.
If you type:
PING SYSNAM02.DFW.COMPANY.COM
the AS/400 system sends SYSNAM02.DFW.COMPANY.COM to the remote name
server. If you type:
PING SYSNAM02
the remote name server reports that the host is unknown. The reason that the
remote name server does not recognize SYSNAM02 is because the AS/400 system
sends the SYSNAM02.A400SSC.DFW.COMPANY.COM name to the remote name
server for resolution. In other words, AS/400 TCP/IP concatenates the local domain
name to the host name.
Chapter 21. TCP/IP Problem Analysis 437