php简单的服务器/客户端（UDP，数据报）无法看到对方

server:

服务器：

 $address = '127.0.0.1';
 $port = 46123;
 if (($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) === false) {
     echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n"; die;
 }
 echo 'socket_create OK '.$address.':'.$port."\n";
 if (socket_bind($sock, $address, $port) === false) {
     echo "socket_bind() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n"; die;
 }
 if (socket_listen($sock, 5) === false) {
     echo "socket_listen() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n"; die;
 }

 do {
     if (($msgsock = socket_accept($sock)) === false) {
         echo "socket_accept() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
         break;
     }
 $address = '127.0.0.1';
 $por