pfSense

function get_nics_with_capabilities($CAPABILITIES) {

	$ifs = `/sbin/ifconfig -l`;

	$if_list = split(" ", $ifs);

	$vlan_native_supp = array();

	foreach($if_list as $if => $iface) {

		$iface = trim($iface);

		$capable = pfSense_get_interface_addresses($iface);

		if(isset($capable['caps'][$CAPABILITIES])) {

			$interfacenonum = remove_numbers($iface);

			if(!in_array($interfacenonum, $vlan_native_supp))

				$vlan_native_supp[] = $interfacenonum;

		}

	}

	return $vlan_native_supp;

}

// Loop through and set vlan_long_frame VLAN_MTU

$vlan_native_supp = get_nics_with_capabilities("vlanmtu");

$g['vlan_long_frame'] = array_merge(array("vge", "bfe",  "bge",  "dc",  "em",  "fxp",  "gem",  "hme",  "ixgb",  "le", "lem", "nge",  "re",  "rl",  "sis",  "sk",  "ste",  "ti",  "tl",  "tx",  "txp",  "vr", "xl", "lagg"), (array)$vlan_native_supp);

function is_jumbo_capable($int) {

        global $g;

        $int_family = preg_split("/[0-9]+/", $int);

        if (in_array($int_family[0], $g['vlan_long_frame']))

        else

                return false;