Re: opening ports
On Mon, Dec 11, 2006 at 08:28:16AM +0100, Jochen Schulz wrote:
> > 1) How would I open ftp ports after doing an apt-get install proftpd?
> On Debian, all ports are "open" by default (but there are not many
> services listening, so it doesn't matter). If a service is being
> installed, it can be assumed that it should actually be available. FTP
> uses ports 20 and 21 (tcp), so if Ubuntu has some iptables rules
> effective by default, you should make exceptions for these ports.
Actually they are called "closed" if no service is listening and "open"
when some service (daemon) is listening. The ports protected by a
firewall are sometimes called "filtered" (by nmap) or "stealth" (by
some Windows firewalls).
If you can't explain it simply, you don't understand it well enough.