The client code starts:

 my $sock = IO::Socket::INET->new("10.0.0.1:5015") or die "$!\n";
 # Write and read messages to socket.

The machine runs Linux (Debian Woody with 2.4.20 kernel)
and Perl (5.6.1).  This is the output of ifconfig:

eth0      Link encap:Ethernet  HWaddr 00:E0:81:B4:77:83  
          inet addr:10.0.0.148  Bcast:10.0.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

eth0:0    Link encap:Ethernet  HWaddr 00:E0:81:B4:77:83  
          inet addr:10.0.0.149  Bcast:10.0.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1