Thanks for the info and pointers!!
Here is a code snippet using those modules (pretty much straight out of the docs, but it might be handy to see an example). In my case I am only looking for a host that, when scanned on the telnet port, will return a hostname, and then I make sure the status is 'up'. Then for all the hosts that are up I do an interface discovery but only using port 23, so the port listing should be changed if you want to discover all open ports, etc..: 
#!/usr/bin/perl -w
use strict;

use Nmap::Scanner;
use NetworkInfo::Discovery;
use NetworkInfo::Discovery::Register;
use NetworkInfo::Discovery::Scan;


my $scanner = new Nmap::Scanner;
$scanner->tcp_connect_scan();
$scanner->add_scan_port(23);
$scanner->max_rtt_timeout(200);
$scanner->add_target('enter range here(eg 192.168.0.1-254)');

#   $results is an instance of Nmap::Scanner::Backend::Results
my $results = $scanner->scan();

my $host_list = $results->get_host_list();

my @upHosts = ();
my $counter = 0;
 
while (my $host = $host_list->get_next()) {
    unless (!$host->hostname()) {
        if( $host->status() eq 'up' ) {
           $upHosts[$counter] =  ($host->addresses)[0]->addr();
           print "Found host named: " . $host->hostname() . "\n";
           print "The host IP is $upHosts[$counter] \n";
           $counter++;
           
        }
    }

}

my $disc = new NetworkInfo::Discovery::Register (
    'file' => '/tmp/scan.register',
    'autosave' => 1
    )
    || warn ("failed to make new obj");

my $scan = new NetworkInfo::Discovery::Scan (
    hosts=>\@upHosts,
    ports=>[23],
    timeout=>1,
    'wait'=>0,
    protocol => 'tcp'
);

$scan->do_it();
$disc->add_interface($_) for ($scan->get_interfaces);

foreach my $h ($scan->get_interfaces) {
    print $h->{ip} . "\n";
    print "    has tcp ports: " . join(',',@{$h->{tcp_open_ports}}) . 
+"\n" if (exists $h->{tcp_open_ports}) ;
}
print "/nThe register looks like:/n";
$disc->print_register;

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In reply to Re^2: Network device discovery with Perl by perldragon80
in thread Network device discovery with Perl by perldragon80

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