How to Block a port for localhost

[Arun Jain]

Hi All,

I have certain ports blocked on the Intranet Firewall, so that no body from outside could connect to server.

But I can connect localhost through that (telnet localhost ). I need to know that how I can block/disable the port on the server so that it could not be connected through localhost itself.

Best Regards
Arun Jain

[Jupinder Bedi]

to block or unblock you can use etc/services /etc/inetd.conf file


and than run inetd -c

[Johnson Punniyalingam]

does the your refering added in your /etc/services ??

you can use /var/adm/inetd.sec to "deny" telnet

man inetd -> for more information

[Horia Chirculescu]

Hello,

Just wanted to point this:

>to block or unblock you can use etc/services /etc/inetd.conf file


From man page:

"The inetd daemon is the Internet superserver, which invokes Internet server processes as needed"

Along with other stand-alone daemons, the from the above definition opens the ports that are opened on the server.

To block a port you must use a firewall rule on the server. In order to stop the process(es) you modify the inetd.conf file. But this means that the processes will be dead after removing the corresponding line from inetd configuration file (and of course restarting the inetd daemon). Dead processes do nothing for anyone regardless the location from where he would want to access that process(es) - localhost or not.


Horia.

[Steven Schweda]

> [...] how I can block/disable the port [...]

Which port are you trying to block? (I
assume that, when you say "block/disable the
port", you really wish to disable one or more
_services_.)


> to block or unblock you can use
> etc/services /etc/inetd.conf file

PLEASE give "/etc/services" a rest. Editing
it is more likely to cause trouble than to do
anything useful.

[Torsten.]

Just make sure there is *nothing* listening to that port (whatever this port is ...?).