pfSense

	/*

	 * We add a fake entry for interfaces that are set to track6

	 * another WAN unless DHCP has been configured

	 */

	foreach ($Iflist as $ifname) {

		/* Do not put in the config an interface which is down */

		if (isset($blacklist[$ifname])) {

			continue;

		}

		if (!empty($config['interfaces'][$ifname]['track6-interface']) && isset($dhcpdv6cfg[$ifname]['enable'])) {

			$realif = get_real_interface($ifname, "inet6");

			$ifcfgipv6 = get_interface_ipv6($ifname);

			if (!is_ipaddrv6($ifcfgipv6)) {

				continue;

			}

			$ifcfgipv6 = Net_IPv6::getNetmask($ifcfgipv6, 64);

			$trackifname = $config['interfaces'][$ifname]['track6-interface'];

			$trackcfg = $config['interfaces'][$trackifname];

			$pdlen = calculate_ipv6_delegation_length($trackifname);

			$ifcfgipv6arr =explode(":", $ifcfgipv6);

			$dhcpdv6cfg[$ifname] = array();

			$dhcpdv6cfg[$ifname]['enable'] = true;

			/* range */

			$ifcfgipv6arr[7] = "1000";

			$dhcpdv6cfg[$ifname]['range'] = array();

			$dhcpdv6cfg[$ifname]['range']['from'] = Net_IPv6::compress(implode(":", $ifcfgipv6arr));

			$ifcfgipv6arr[7] = "2000";

			$dhcpdv6cfg[$ifname]['range']['to'] = Net_IPv6::compress(implode(":", $ifcfgipv6arr));

			/* prefix length > 0? We can add dhcp6 prefix delegation server */

			if ($pdlen > 2) {

				$pdlenmax = $pdlen;

				$pdlenhalf = $pdlenmax -1;

				$pdlenmin = (64 - ceil($pdlenhalf / 4));

				$dhcpdv6cfg[$ifname]['prefixrange'] = array();

				$dhcpdv6cfg[$ifname]['prefixrange']['prefixlength'] = $pdlenmin;

				/* set the delegation start to half the current address block */

				$range = Net_IPv6::parseAddress($ifcfgipv6, (64 - $pdlenmax));

				$range['start'] = Net_IPv6::getNetmask($range['end'], (64 - $pdlenhalf));

				/* set the end range to a multiple of the prefix delegation size, required by dhcpd */

				$range = Net_IPv6::parseAddress($range['end'], (64 - $pdlenhalf));

				$range['end'] = Net_IPv6::getNetmask($range['end'], (64 - round($pdlen / 2)));

				$dhcpdv6cfg[$ifname]['prefixrange']['from'] = Net_IPv6::compress($range['start']);

				$dhcpdv6cfg[$ifname]['prefixrange']['to'] = Net_IPv6::compress($range['end']);

			}

			$dhcpdv6cfg[$ifname]['dns6ip'] = get_interface_ipv6($ifname);

		}

	}