/usr/share/doc/libnet-ip-perl/examples/iptab is in libnet-ip-perl 1.25-3.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | #!/usr/bin/perl
use Net::IP;
use strict;
print "+----------------------------------------------+
| addrs bits pref class mask |
+----------------------------------------------+
";
my ($ip,$size,$class,$bits,$len);
my $ip = new Net::IP('0');
for my $len (reverse (0..32))
{
$ip->set("0.0.0.0/$len");
$size = $ip->size();
if ($size >=1048576) # 1024*1024
{
$size /= 1048576;
$size .= 'M';
}
elsif ($size >= 1024)
{
$size /= 1024;
$size .= 'K';
};
$len = $ip->prefixlen();
$bits = 32 - $len;
if ($bits >= 24)
{
$class = 2**($bits-24);
$class.= 'A';
}
elsif ($bits >= 16)
{
$class = 2**($bits-16);
$class.= 'B';
}
elsif ($bits >= 8)
{
$class = 2**($bits-8);
$class.= 'C';
}
printf ("| %5s %6s %6s %7s %-15s |\n",
$size,$bits,'/'.$len,$class,$ip->mask());
};
print "+----------------------------------------------+\n";
|