RE: Linux OS help

> Task 1. Change server name (IP address remains the same).
> I am looking for info. on how to change server name.

man hostname:

   hostname newhostname

This will change your system's hostname right away I believe; whether it sets it
permanently in any config files I'm not yet sure.

> Does server name change effect software on the server (example Oracle server
> ...etc) ?

It *can*, but depends on the software. Apache and Sendmail, for example, are
affected and generally need simply to be restarted to take effect.


> For below mentioned services I was told "Port is open"
> I want to know how to close ports.
> Just in case If I close a wrong port or a required port I want to find the
> ports and open a closed port (if necessary).

ssh means that 'sshd' is running.
telnet, etc.
smtp = sendmail
etc
etc

You can shut off services using 'setup' (run from the local console, preferably)
under the 'system services' menu option.

> In short I am looking for command for to find out open and closed
> ports(services)

netstat -an

This will list all open ports, listening and connected, etc

> Command to close a open port (service)

/sbin/service httpd stop
/sbin/service sendmail stop
etc

> Command to open a closed port (service)

/sbin/service httpd start
/sbin/service sendmail start
etc

> Task 3. Applying patches (security patches).
> Where can I get OS patches ?
> Where can I get instructions on how to apply patches ?

https://rhn.redhat.com/

You'll have to register your system using 'rhn_register' then you can use
'up2date' utility either through Xwindows (Gnome, KDE, etc) or from the command
line.

RedHat also has a newletter alert system that will Email you when new packages
are ready to go so you know when to manually run up2date.

Or, if you subscribe to their RHN service you can set your machine to query
RedHat every so often (default and lowest time range is 120 minutes) to see if
there are any new RPM packages to update and automatically update your system.

> If I run into problems who will be able to help.
> Don't tell me Linux Support .....!

Okay, I won't tell you ...

Welcome to the open source community ;o)

If you *purchased* a copy of RedHat, I believe you get varying amounts of
support but I don't know how much - I believe it depends on the version, which
package (standard, pro, etc).

-id