Closing port 631 from other computers

[Jarmo Hurri]

Ed Greshko <ed.greshko at greshko.com> writes:
> cupsd 2349 root 10u IPv4 37790 0t0 TCP *:ipp (LISTEN)
> Does indicate that it is listening on all interfaces.  You can prevent
> this by editing your /etc/cups/cupsd.conf to contain the line....
> Listen localhost:631
> Which will result in
> cupsd     2377     root   11u  IPv4  29156      0t0  TCP localhost:ipp (LISTEN)
> If you do only that, the port will remain "open" but nobody outside of
> your system will be able to communicate.

I'll try this.

> Next, please note that iptables.service is different from and separate
> to firewalld.service.  So, forget about it.

I know, I just wanted to show that iptables is *not* running.

> Also, you can use firewall-config to manage basic firewalld setting
> from a GUI.  To close the port you'd uncheck "ipp" ....  kind of
> obvious.  Now, the kicker is that there are multiple zones and you
> should check to ensure your network interface is tied to the zone you
> are changing.

The thing is, ipp is not checked in *any* interface. This is also shown
in the outputs I gave earlier:

************************************************************************
[jarmo at localhost ~]$ firewall-cmd --get-active-zones
public
  interfaces: em1

[jarmo at localhost ~]$ firewall-cmd --zone=public --list-ports

[jarmo at localhost ~]$ firewall-cmd --zone=public --list-all
public (default, active)
  interfaces: em1
  sources: 
  services: dhcpv6-client mdns
  ports: 
  masquerade: no
  forward-ports: 
  icmp-blocks: 
  rich rules: 
************************************************************************

These also show that my active interface is in public zone, and ipp is
not enabled. So I still do not understand how the port can be open.

Jarmo