sub CheckServers {
	
    # go down the list of servers
    # and sent a packet to each
    # one to request info
    
    my $socket = IO::Socket::INET->new( Proto => 'udp', 
                                        Type => SOCK_DGRAM);

    my $select = IO::Select->new($socket);
    my %responses;
	    
CHECK_SERVERS:

    while (@servers){
    	my $toread = $select;
    	my $towrite = @servers ? $select : undef;
    	my ($readref, $writeref) = 
            IO::Select->select( $toread,$towrite,undef,$timeout );
     
    	last unless ($readref || $writeref);   
    			
    	foreach my $sock ( @{ $writeref } ) {
    		
			$sent++;
    		my $server = shift @servers; 
	    	my ($ip, $port) = split (/.:/, $server);
			
	    	next unless $port && $ip;

	    	my $paddr = sockaddr_in($port, inet_aton($ip));
				
	    	my $ret = $sock->send($HOST_QUERY, 0, $paddr) 
               || die "send: $!";
	    	$waiting{$ip} = Time::HiRes::time;
		
    	}
		
    	foreach my $sock ( @{ $readref } ) {	
				
			$rcvd++;
    	    my $rc = $sock->recv($reply, 10_000);
    	    next unless $rc;
    	    my ($port, $addr) = sockaddr_in($rc); 
    	    my $ip = inet_ntoa($addr); 
			
    	    if ( $reply ) {
    	    	... do stuff ...
                     }    			
		
    	next CHECK_SERVERS;

    	}
    }
}