HP-UX Internet Services Administrator's Guide (August 2003)
Troubleshooting Internet Services
Troubleshooting Tips
Chapter 5104
Troubleshooting Tips
This section provides useful tips for troubleshooting the Internet
Services software.
When troubleshooting problems with the Internet Services, you need a
reference point to work from. For example, does the problem exist on the
remote system or on the local system? However, the terms local and
remote are limited in their description of complex communications, such
as when a local system logs on to a remote system and then the remote
system logs back on to the local system. At that point, which is the local
system and which is the remote system?
A better solution is to use the terms client and server. The term client
refers to a process that is requesting a service from another process. The
term server refers to a process or host that performs operations
requested by local or remote hosts that are running client processes.
HP has implemented a super-server known as the Internet daemon,
inetd. This program acts like a switchboard; that is, it listens for any
request and activates the appropriate server based on the request.
A typical network service consists of two co-operating programs. The
client program runs on the requesting system. The server program runs
on the system with which you want your system to communicate. The
client program initiates requests to communicate. The server program
accepts requests for communication. For example, the network service
rlogin is the client program that requests a login to a remote HP-UX or
other UNIX system. When the request to log in is received on the remote
host by inetd, inetd invokes the server program for rlogin (called
rlogind) to handle the service request.