Upon initial boot of your Red Hat box, you may be confused as to why you cannot access the web server, telnet, secure shell (ssh), POP servers, or other server processes. Most likely this is a result of the daemon not being turned on.

Daemon startup is enabled by the chkconfig tool in RedHat. To see a list of the status of all daemons in RedHat you can type "chkconfig --list"

Runlevels
UNIX has different runlevels. On Red Hat, you will usually be in runlevel 3. You can see your previous, and current runlevel by typing "runlevel". Chkconfig displays the status of each daemon in each runlevel. This is automatically set by the chkconfig command. Typically you want to see an "on" after the "3:" of any server you wish to enable.

Looking at the condensed list of services below, you can see that the RedHat machine has sendmail and secure shell (sshd) enabled, while Simple Network Management Protocol (snmpd) and the Web server (httpd) are turned off.

sendmail 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sshd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
httpd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
snmpd 0:off 1:off 2:off 3:off 4:off 5:off 6:off

Using chkconfig
After determining the services you want to turn on, it's time to enable them. This can be done using the following command:
chkconfig name on

Be sure to fill in the name of the daemon where name is italicized. For example, to turn on the web server, log in as root and type:
chkconfig httpd on

Daemon Control
Typing the above command will enable the web server the next time you boot up. In addition to this, you may force the server to start up without rebooting by typing:
service httpd start

You can also stop the web server by typing:
service httpd stop

Or check on the status of a daemon by typing:
service httpd status

After making changes to a config file, in Apache's case it would be /etc/httpd/conf/httpd.conf, you need to restart the daemon. This is the equivalent of typing the stop command followed by the start command. This is done as follows:
service httpd restart

Connectivity Problems
After turning a service on, you may have the problem of only accessing it. This may be due to firewall restrictions running on the Red Hat box. You can administrate the firewall (and will most likely need to do so) by using the lokkit program.
Click here to learn how to administrate the firewall using lokkit.