Catch HttpSocket exception ? (ver. 2.x)

Hi all,
How to catch :
(that catch doesn’t work)
try {
$response = $http->post($link, $xml, $request);
} catch (Exception $e) {
debug(‘STOP Error’);
}
I try to catch this error: “php_network_getaddresses: getaddrinfo failed: Name or service not known”.

Thank you.