Tag Archives: IPv6

Matching IPv6 addresses with Regexp::Common

I wish Regexp::Common had a $RE{net}{IPv6} regular expression, but it doesn't (yet).

So I tried to implement this myself, but ripped off the IPv6 matching bit from the existing Regexp::IPv6 which happens to have a working IPv6 regular expression with a reasonable test suite. Now, why Regexp::IPv6 is not part of Regexp::Common?

By the way, I'll copy/paste the full regular expression to match IPv6 addresses, just for fun:


Of course, I will never be able to tell if it's right or wrong, but the fact is that it passes the test suite :)
However, the actual code is not like that: it generates the full regular expression from a few components. Anyway, I've pushed a ipv6 branch on my fork of Regexp::Common. I hope it will be included soon in Regexp::Common or improved it enough to be included in it, so we can finally match IPv6 addresses with:

use Regexp::Common;

my $addr = '2001:0db8:0000:0000:0000:0000:1428:57ab';
if ($addr =~ $RE{net}{IPv6}) {
    print "Yes, it is an IPv6 address";
else {
    print "No, it isn't";

Geo::IP support for IPv6 geolocation

We're currently looking into IPv6-enabling our services. One of the missing bits is being able to geolocate IPv6 client addresses. We're using the MaxMind GeoIP database. The main Perl library for this is Geo::IP.

The current version of Geo::IP out on CPAN, 1.38, does not support IPv6 lookups. I contacted the maintainer of Geo::IP asking for more information. In the meanwhile, I hacked together just enough of IPv6 support to be able to successfully geolocate a test address. Later on, I discovered that IPv6 is already available in the hopefully soon-to-be-released version of Geo::IP archived at Sourceforge.

Let's hope it lands on CPAN soon. In the meantime, if you really really want, you can try out my changes against CPAN v1.38. It was enough for me to start testing the integration with our other code and projects.

My Geo::IP with IPv6 support

IPv6 and Perl. What’s the status?

This is more like a request for help than the usual babbling about something. IPv4 address space appears to be almost entirely allocated. IPv6 is there, ready for us to use (more or less).

I'm trying to reserve some time to prepare and test our systems for client and server IPv6 addresses. What is your experience in particular with Perl software? I know almost nothing about it, except there's:

I tried to download and test Net::IPv6Address, but that didn't work, tests fail, and the module is also last updated in 2008… Can you enlighten me on what's the state of the art regarding Perl (but not only, ofc) and IPv6? KTHXBYE.

In the meanwhile, I'll read a bit more on the whole IPv6 matter. First task: write an anonymizer for a IPv6 address.