Hey, are you new to Firewalld like most of us?
Unless you have been using Firewalld in the last few releases of Fedora, as some out there have, then you probably could probably use a few pointers to get you started on your way to configuring your Linux firewalls the “new-fangled fancy way”. This is especially the case if you plan on moving to RHEL7 anytime soon — as Firewalld is the default there. So put on your big boy (or girl) pants and say goodbye to your old friend IPTABLES.
According to this page. Firewalld is…
“The dynamic firewall daemon firewalld provides a dynamically managed firewall with support for network “zones” to assign a level of trust to a network and its associated connections and interfaces. It has support for IPv4 and IPv6 firewall settings. It supports Ethernet bridges and has a separation of runtime and permanent configuration options. It also has an interface for services or applications to add firewall rules directly”
Wow, how fancy. So how do we use it? Well let’s take a stab at enabling HTTP access to our Fedora21 workstation.
First thing first, lets figure out what our default done is on our workstation.
$ sudo firewall-cmd –get-default-zone
FedoraWorkstation
Ok, thats a bit strange, in RHEL you should expect PUBLIC to be your default zone. Now that we know what zone we need to mess with let’s make sure that its applied to the proper interfaces.
$ sudo firewall-cmd –get-active-zone
FedoraWorkstation
interfaces: enp4s0 enp5s4 macvtap0 tun0 virbr0
The first two interfaces above are our physical interfaces, so we are good here. Now lets apply the rule, and make sure its permanent.
$ sudo firewall-cmd –permanent –zone=FedoraWorkstation –add-service http
success
Now lets check our rules. Note HTTP is missing.
$ sudo firewall-cmd –list-services
dhcpv6-client mdns samba-client ssh
Since we have only applied this new rule to our permanent config and not to our running config, we need to restart firewalld to see the updated rule.
$ sudo firewall-cmd –reload
Now your can view the updated rules…
$ sudo firewall-cmd –list-services
dhcpv6-client http mdns samba-client ssh