[CentOS] CentOS-6 firewall how to open a port

Timothy Murphy wrote:
I'm running CentOS-6 on an HP MicroServer (since this morning)
and I'd like to open an non-standard port,
for use on a laptop attached to the internet through the server.

Do I have to explicitly add an iptables rule?
If so, and I want to open (say) udp port 500 ,
what command should I give?

I've always used shorewall in the past,
and will probably do so now if the default firewall is difficult to use.
But I thought I would try it first as an experiment.

My recollection is that in old versions of CentOS
one could non-standard ports through system-config-firewall ;
but it seems that now this can only be used for standard ports;

I looked at <http://wiki.centos.org/HowTos/Network/IPTables>
but didn't find it very enlightening.

Any advice or suggestions gratefully received.

At 08:53 AM 7/17/2011, you wrote:
Timothy Murphy wrote:

On Sun, Jul 17, 2011 at 6:05 PM, david wrote:
(snip)

I loaded my system with text-install and network, and find no file
named "/usr/bin/system-config-firewall". ?My guess is that it comes
with a package that I haven't installed. ?Can you identify that package?

Thanks
David

_______________________________________________

Timothy Murphy wrote:

I'm running CentOS-6 on an HP MicroServer (since this morning)
and I'd like to open an non-standard port,
for use on a laptop attached to the internet through the server.

Do I have to explicitly add an iptables rule?
If so, and I want to open (say) udp port 500 ,
what command should I give? ...
My recollection is that in old versions of CentOS
one could non-standard ports through system-config-firewall ;
but it seems that now this can only be used for standard ports;

Timothy Murphy wrote:
There does seem to be a bug/feature: if you enter
the same procedure by Administration=>Firewall (in KDE)
you cannot make any changes (at least I could not)
even after giving the superuser password, when requested.