I would like to close off a port on a Linux Redhat 7.1 system. How shall I go about that?

That would depend on the port and what you mean by "close up". If you have a firewall installed (ipchains etc.) you can just block everything going to that port.

If it's something started by inetd (finger, telnet etc.) you can comment the line out of /etc/inetd.conf and then hup inetd.

A little more details would help.

Frank

You can also filter this at your router, if you have a Cisco.

Drew N.

If you are running a default install, you probably have iptables installed, so

/sbin/iptables -A INPUT -i eth0 -p tcp --dport 23 -j DENY

would block all incoming telnet traffic on eth0.