Category: CommunityFeature Spotlight: IPv6 Pools and Subpools

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1.2 septillion.  As long as you’re OK writing off 8.9 sextillion IP Addresses as a rounding error.

That’s how many IPv6s come in a /48, which is ARIN‘s default (minimum, actually) allocation.  If you can demonstrate the need, they’ll give you a /44, /40, /36, or even a /32.

New to IPv6 & CIDR notation? Check out the basics here: IPv6, CIDR Notation

That’s not a small number.  Actually, it’s a very, very, very large number, give or take a few “verys” — I had to check Wikipedia to see what to call it.  While the problem with IPv4 was that you needed more, IPv6 presents the novel issue of needing to be able to keep track of what you have!

With InterWorx 5 (coming soon, beta 3 available now) we’ve introduced the concept of IPv6 Pools, further refined with IPv6 Subpools.  This article is an outline of what IPv6 Pools do so you can think about how they’ll fit into your business.

IPv6 Pools

To help manage the vast number of IPv6 addresses, InterWorx came up with the concept of pooling them together.  By assigning a subnet of IPv6 from your total allocation to an InterWorx IPv6 Pool, you can allow InterWorx to manage the assignment of individual addresses to master and secondary domains as they are created on your server.

Distribution of IPv6 addresses can be sequential or random.

IPv6 Subpools

As pointed out to us by our wonderful beta testers, sometimes clients in the hosting industry can be a bit…unruly.  With a shared IPv6 Pool, no matter the distribution policy, you nearly always wind up with overlapping IPv6 addresses, making it rather difficult to filter network traffic for a single customer.

Enter IPv6 Subpools.  By specifying the size of the Subpool when creating a Pool, InterWorx will dole out dedicated subpools to each SiteWorx account as you create them, and distribute IPv6 addresses from those dedicated pools as the SiteWorx account needs them.

IPv6 Pool and Subpool adding

Suggested Use of IPv6 Pools

So, how does all this work in practice?

What Gets an IPv6 Address?

Master domains and secondary domains can have IPv6 addresses.  Other domain types, such as pointers and subdomains, share the IPv6 of the domains they are associated with, just like IPv4.  InterWorx sets up IPv6 addresses from a Pool to be dedicated – meaning they cannot be used by other SiteWorx accounts.  This means that the IPv6 will be SSL-Ready, so if the IPv4 in use by the domain is also dedicated, SSL Certificates can be set up for the domain.

Suggested Setup

With all these ridiculously large numbers, there are hundreds of ways to set things up.  Our recommendation tries to balance numbers that are small enough to actually think about, without too much risk that your server will ever run out.

InterWorx recommends allocating /96s to your individual servers out of your full allocation, with a Subpool Size of /112.  A /96 will have 4.3 billion IPv6 addresses, and dividing that into Subpools at a size of /112 yields 65,356 Subpools, each containing 65,536 IPv6 Addresses.  This makes it pretty unlikely that you’ll ever exhaust the Pool.

Given that the default allocation of a /48 will yield something like 281 trillion /96s, it’s pretty unlikely that you’ll run out of those.  Actually, if you’re in danger of that, well…perhaps we can work out a volume discount for you.


Try it out for yourself by joining the InterWorx 5.0 beta program!

5.0Feature SpotlightIPv6
Mar 26, 2013, 11:57 amBy: Tim College (0) Comments

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