How to stop FTP and Telnet services?

makkays · 11-28-2006, 01:32 AM

hello,

I have stopped telnet and wu-ftp serivices by following command:

% chkconfig telnet off
% chkconfig wu-ftpd off
when i ftp and telnet they are not availble after it.

but when i check the following file /etc/services i find that ftp is on on both TCP/UDP and similrly telnet is available on TCP/UDP both protocols.

Now do i have to comment out the refrenced lines in file /etc/services or are the services closed by above mentioned command.

kindly guide me

makkays

chort · 11-28-2006, 02:15 AM

/etc/services is only a name-to-number/number-to-name mapping table. That file does not disable or enable any services.

makkays · 11-28-2006, 10:25 PM

thanks,

kindly confirm whether After running "chkconfig telnet off " it means that telnet services are off on both TCP/udp ports? and

also is this true that name-to-number/number-to-name mapping is created on installation of OS, so even if i am not using a perticular service the mapping will be there by default.

regards

makkays

Wim Sturkenboom · 11-29-2006, 02:05 AM

Quote:

Originally Posted by makkays

kindly confirm whether After running "chkconfig telnet off " it means that telnet services are off on both TCP/udp ports?

There is only one telnet service/daemon. Switching it 'off' only means that it does not run (regardless of the protocol).

Quote:

Originally Posted by makkays

also is this true that name-to-number/number-to-name mapping is created on installation of OS, so even if i am not using a perticular service the mapping will be there by default.

Yes, although I'm quite sure that it's just a file that is copied from the installation CD during installation (so not really created).

chort · 11-29-2006, 02:28 AM

Telnet and FTP only use TCP. The fact that they have reserved UDP ports is from the legacy days of the early Internet.

imran-rhce · 11-29-2006, 02:48 PM

I want to mention that telnet is controlled by xinetd service in latest version's of Redhat Linux

"Chkconfig telnet off" stop's the telnet session & can also be confirmed from /etc/xinetd.d/telnet with "disable = yes" option

you can alternatively make use of Tcp_wrappers(/etc/hosts.allow) to control telnet

makkays · 11-29-2006, 11:42 PM

Thanks everybody.the concept is really clear now

regards

makkays