Hm. Now I am confused (and/or stupid; your choice). I was thinking that perhaps Net::Ping would support which port to perform a "tcp ping" against (after all, there is a hash element called "port_num") in the initialization of the class:

elsif ($self->{"proto"} eq "tcp")           
{
  $self->{"proto_num"} = (getprotobyname('tcp'))[2] ||
  croak("Can't get tcp protocol by name");
  $self->{"port_num"} = (getservbyname('echo', 'tcp'))[2] ||
  croak("Can't get tcp echo port by name");
  $self->{"fh"} = FileHandle->new();
}
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So I figured I'd create the class and modify $self->{"port_num"} by myself. Well, I've run into a problem: the following code doesn't work:

#!/usr/bin/perl 
 
use Net::Ping; 
 
$host="localhost"; 
 
$p = Net::Ping->new(); 
print "$host is alive.\n" if $p->ping($host); 
$p->close();
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It produces the error message of

Bad arg length for Socket::unpack_sockaddr_in, length is 0, should be 
+16 at /usr/lib/perl5/5.00503/i386-linux/Socket.pm line 295.
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Now, I realize that I'm probably missing something here, but I can't figure out what it is; after all, this example is the first listed in the pod for Net::Ping.

Any ideas?