[TriLUG] Cant close port 23 on firewall

Phillip Rhodes mindcrime at cpphacker.co.uk
Sat Jan 28 22:26:30 EST 2006


Neil L. Little wrote:

> I did a port scan on a system runing FC4 and found that I had port 23 open.
<snip>
> I quick search on Google and a couple of forums didnt score any hits.
> Can anyone point me in the right direction?

You can use chkconfig --list to see what services
are set to startup at boot-time.  See if you actually
do have a telnet server set to start by accident.

Or telnet might be configured as an xinetd service,
look in /etc/xinetd.d and see if there's a 'telnet'
file there.  If there is, edit it and set

disable = YES

to disable the service.

You can also try doing

netstat -tupa | grep '23'

and see what process is bound to port 23, if one actually is.

Outside of that, if you intention is to run a firewall,
your iptables rules should have at least the WAN interface 
(and ideally all interfaces) set for a default policy of 
DROP, with only the specific ports set for ACCEPT that you 
desire to receive traffic on.


TTYL,


Phil
-- 
North Carolina - First In Freedom

Free America - Vote Libertarian
www.lp.org




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