Closing port 631 from other computers

[Ed Greshko]

On 10/31/14 18:09, Jarmo Hurri wrote:
> 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.

OK....

>> 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.

I see....  Good to know.
>
>> 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.
>

That is "odd" what does

iptables -L -n | grep 631

Show?


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