I'm trying to test out the success or failure of sending a UDP message to a set of servers which may be up or down.

On the port range I have chosen, the response seems to alternate and not be the same each time, I have waded back and forth through the perldoc and the cookbook for a clue, to no avail, so is it a problem with my use of the IO modules?

I am getting: 

READ *3*
READ *0*
Read IO select timed out at ./socket.pl line 24.
READ *3*
READ *0*
Read IO select timed out at ./socket.pl line 24

when instead I want four dies in a row.... code below: 

#!/usr/local/bin/perl -w
use strict;

use IO::Select;
use IO::Socket;

my $server = '127.0.0.1';

for (8721 .. 8724) {
    my $fd = new IO::Socket::INET( PeerAddr => $server,
                                   PeerPort => $_,
                                   Proto    => 'udp');

    my $sockin = new IO::Select( $fd );

    eval {
        $fd->send( 'Test string' );
        my $read = IO::Select->select( $sockin, undef, undef, 3);
        print "READ *$read*\n";
        die "IO select timed out" unless $read;
    };

    print "Read $@" if $@;
}

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In reply to Socket response inconsistent by agoth

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