pfSense

		if ($post['enable_stun']) {

			if (!$post['stun_host'] || (!is_ipaddrv4($post['stun_host']) && !is_hostname($post['stun_host']))) {

				$input_errors[] = 'A valid IP address or hostname for \'STUN Server\' must be specified';

			}

			if (!$post['stun_port'] || !is_port($post['stun_port'])) {

				$input_errors[] = 'A valid port number for \'STUN Port\' must be specified';

			}

		}

				/* STUN configuration */

				if ($upnp_config['enable_stun']) {

					$config_text .= "ext_perform_stun=yes\n";

					$config_text .= "ext_stun_host={$upnp_config['stun_host']}\n";

					$config_text .= "ext_stun_port={$upnp_config['stun_port']}\n";

				}

		<field>

			<name>STUN Configuration</name>

			<type>listtopic</type>

		</field>

		<field>

			<name>STUN Help</name>

			<type>info</type>

			<description>

				The External interface must have a public IP address. Otherwise it is behind NAT and port

				forwarding is impossible. In some cases the External interface can be behind unrestricted NAT 1:1

				when all incoming traffic is forwarded and routed to the External interface without any filtering.

				In these cases UPnP service needs to know the public IP address and it can be learned by asking an

				external server via STUN protocol. The following option enables retrieving the external public IP

			       	address from a STUN server and detection of the NAT type.

			</description>

		</field>

		<field>

			<fielddescr>Enable STUN</fielddescr>

			<fieldname>enable_stun</fieldname>

			<type>checkbox</type>

			<description>Enable retvieving external IP address from STUN server.</description>

			<enablefields>stun_host,stun_port</enablefields>

		</field>

		<field>

			<fielddescr>STUN Server</fielddescr>

			<fieldname>stun_host</fieldname>

			<type>input</type>

			<description>

				<![CDATA[

				STUN Server, either hostname or IP address.</br></br>

				Some public STUN servers:</br>

				stun.sipgate.net</br>

				stun.xten.com</br>

				stun.l.google.com (on non standard port 19302)</br>

				]]>

			</description>

		</field>

		<field>

			<fielddescr>STUN Port</fielddescr>

			<fieldname>stun_port</fieldname>

			<type>input</type>

			<default_value>3478</default_value>

			<description>STUN UDP port (Default: 3478)</description>

		</field>