if (!$ssh->start_session($ssh_host)) {
      print "ERROR connecting to $ssh_host\n";
      return 1;
   }

   my ($ret,$err)=$ssh->execute('command1','expect1');
   if ($err || $ret=~/Unknown command:/m) {
      $ssh->exit_session();
      $ssh->close_session;
      return 2;
   }

   my ($ret,$err)=$ssh->execute('command2','expect2');
   if ($err || $ret=~/Unknown command:/m) {
      $ssh->exit_session();
      $ssh->close_session;
      return 3;
   }