Installing and Administering Internet Services

Chapter 12 475
Troubleshooting Internet Services
Troubleshooting the Internet Services
1B. List current servers. List the servers currently running
on your system by executing the following:
netstat -a
Table 12-3 lists the servers required for each service.
Note that UDP-based protocols are datagram driven so they do not show
a TCP LISTEN status.
1C. Server exists for service? If the server does not exist for
the requested service, continue with 1D to determine
why. If the server does exist for the server, continue
with 1C1.
1C1. Go to Flowchart 2. Go to the next flowchart to begin
troubleshooting the security of the Internet Services.
1D. Are files correct? Is there an entry for the servers or
services in the /etc/inetd.conf or /etc/services
files?
Table 12-3 Servers Required for Each Service
Local Address Client/Request TCP State
*.ftp ftp LISTEN
*.telnet telnet LISTEN
*.login rlogin LISTEN
*.shell remsh, rcp LISTEN
*.exec rexec library LISTEN
*.who rwho, ruptime
*.smtp sendmail SMTP LISTEN
*.tftp tftp LISTEN
*.bootps bootpd LISTEN
*.finger fingerd LISTEN