My machines were both in the same room, on the same router and subnet. Firewall software on both machines (Linux and OS X) prevented the connection.

This code will give you a functional server you can telnet into. Don't use it for anything but testing:

#!/usr/bin/perl -w

use strict;
use IO::Socket;

my $sock = IO::Socket::INET->new(  Listen    => 1,
                        LocalAddr => 'localhost',
                        LocalPort => 9000,
) || die "Unable to create socket: $!\n";

print "Waiting for message...\n";

while ( my $fh = $sock->accept()) {
    print while <$fh>;        
}
close ($sock);
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