Ubuntu

1)how to enable and disable ports in linux.

2)AND how to disable unknown ports

To disable:
Just comment out lines in /etc/inetd.conf. Then restart inetd for the changes to take effect.

Code:

netstat -a

netstat lets you search for open ports which do not use inetd. Then turn off those proccesses individually.

To enable - uncomment inetd.conf

I do not know anything about unkown ports. You cannot block something you do know about ahead of time...? Or do you mean prevent some specific port number from ever being used?

If it is not a service, then you have to use a firewall to block/allow a specific port, not inetd.conf.
You can really mess things up by turning off required services or blocking required ports. Example: port 22
see here for IANA ports:
http://en.wikipedia.org/wiki/List_of...P_port_numbers

how to turn these processes individually.
PORT STATE SERVICE
1100/tcp open unknown



---------- Post updated at 07:24 AM ---------- Previous update was at 07:23 AM ----------

how to turn off these process individually
PORT STATE SERVICE

1100/tcp open unknown

Before you kill the process, be sure it is not important.

What does

Code:

netstat -a | grep 1100

show

what about udp ports which are open.

nmap does not show udp ports which are kept open
how to disable them ?

You can block any port with DROP in iptables. netstat shows UDP ports

Code:

netstat -a | grep UDP

shows ports held open

Without some input from you - helping is hard to do.