IPv6 IP addresses!

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Many of us are at least sort of vaguely aware that “the world is running out of IP addresses”.  And by this we mean IP addresses like 162.255.116.157 — four numbers each in the range of 000 to 255.  These are called IPv4 IP addresses.  But there is also a newer kind of IP addresses called IPv6 IP addresses.  I was fascinated recently to find out that my firm has some of these newer kind of IP addresses. 

IPv4 uses a 32-bit address space which provides 4,294,967,296 (232) unique addresses, although substantial portions of that space are set aside for particular uses.  That space ran out in 2011.  In an effort to deal with this, the IETF set up the IPv6 standard in 1998. IPv6 uses a 128-bit address, theoretically allowing 2128, or approximately 3.4×1038 addresses.  IPv6 addresses are represented as eight groups, separated by colons, of four hexadecimal digits, so an example of an IPv6 address might be 2001:0db8:0000:0000:0000:8a2e:0370:7334.   There are several notational conventions that allow you to leave out some of the digits under some circumstances, and so very often a particular IPv6 address is capable of being communicated with fewer than thirty-two digits.

The main point of this blog article is to share that I learned recently that several of the servers that my firm operates in a server farm in Arizona have IPv6 addresses assigned to them in addition to having IPv4 addresses assigned to them.  So for example our server that hosts this blog has not only the IPv4 address 162.255.116.157 but also the IPv6 address 2607:7700:0:1f:0:1:a2ff:749d.

I also have found that the Internet service providers serving the work-from-home locations for many people in our firm are providing not only IPv4 addresses but also IPv6 addresses to those Internet connections.  

Are you using IPv6 addresses?  Please post a comment below.

7 thoughts on “IPv6 IP addresses!

  1. Do ISPs provided fixed, rout-able IPv6 addresses for a lower price than IPv4 prices?

    Since there are so many more IPv6 addresses they ought to be cheaper….

    The first time I had a non-dial-up link to the internet, the ISP just threw in 16 fixed addresses without being asked.

    If we had started with IPv6, would NAT have ever been invented?

    • You asked:

      If we had started with IPv6, would NAT have ever been invented?

      I am absolutely sure that the answer to your question is, no, if we had started with IPv6, NAT would never have needed to exist and would never have been invented.

      There are many evil things about NAT, which I have discussed here and here and here. All of those evils, and many more, would have been avoided if our world had never needed to have NAT in it.

    • You asked:

      Do ISPs provided fixed, rout-able IPv6 addresses for a lower price than IPv4 prices?
      Since there are so many more IPv6 addresses they ought to be cheaper….

      Your question turns out to be simpler to answer than you might imagine.

      It turns out that the state of nature is that IPv6 addresses are routable. In general if somebody hands you an IPv6 address it is routable. It also turns out that many routers nowadays have an IPv6 stack that you can turn on if you want, that will make full use of IPv6 if the ISP makes IPv6 available. It also turns out that many ISPs will, at no extra charge, give your router an IPv6 “prefix” just for the asking, which is the first couple dozen bits of an IPv6 address, and then your router is given carte blanche to fill in the last half a dozen bits however the router feels like filling them in. Oh and guess what, the resultant IPv6 addresses are all by definition routable. No NAT was required to make those fully populated IPv6 addresses come into existence. Now I guess those are dynamic and the lease lasts only so long. So if the ISP gives you ten thousand addresses today, you can’t be sure you will get the same super generous sized block tomorrow. But I sort of vaguely figure what will finally settle down is ISPs will tend to hand out blocks of 256 at a time, so that it works out about the same as old-fashioned NAT. And yes they will be routable by definition. And free of charge, by which I mean, no extra cost above and beyond what you are paying for your internet access generally. But not static.

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