The route I recently went that worked well for the mix of IPv4 addresses and ranges that I had was to, for IPv4 addresses, just use the IP address as a hash key. For IP ranges, I used the first 3 octets of the range as the hash key and the value was a list of ranges that I looped through (it was rare that I had more than one range having the same first three octets). I didn't have any ranges that covered more than one three-octet block, but if I had, I would split such ranges up.
my %hash= (
'127.0.0.1' => 'localhost',
'10.11.12.1' => 'router',
'10.11.12.10' => 'desktop',
'10.11.12.' => [
{ min => 101, max => 120, desc => 'printers' },
{ min => 250, max => 254, desc => 'tanks' },
],
);
sub findIP {
my( $ip )= @_;
my $desc= $hash{$ip};
return( $ip, $desc )
if $desc;
my( $last )= $ip =~ s/(\d+)$//;
my $ranges= $hash{$ip};
for my $range ( @{ $ranges || [] } ) {
my( $min, $max )= @$range{'min','max'};
return( "$ip.$min-$max", $range->{desc} )
if $min <= $last && $last <= $max;
}
return;
}