Well done for providing some code to illustrate the problem. Unfortunately what your code demonstrates is merely that the target addresses are not responding to the Net::Ping tests, it passes no judgement on whether or not the addresses are "recognized".

use strict;
use warnings;

use Test::More tests => 7;
use Net::Ping;

my $p = Net::Ping->new;
for my $host (qw/www.perlmonks.org tcpbin.com/) {
    ok $p->ping ($host), "$host pinged";
}
for my $host (qw/www.ibm.com www.whitehouse.gov/) {
    ok !$p->ping ($host), "$host blocks pings";
}
for my $host (qw/lsdfskf wocka.wocka 192.168.1/) {
    ok !$p->ping ($host), "$host doesn't respond because it won't reso
+lve";
}
[download]

Note how the second and third sets behave the same in terms of the false return value from the ping method despite failing in different ways.