IPv4 shortage is now becoming a reality – what is needed for IPv6 to work

ipv4ipv6

Today I read that Microsoft has no more IPv4 addresses for its Azure cloud. Earlier this week I read that Latin America is out of IPv4 addresses as well. These are real – not predicted – IPv4 address shortages. I remember we had IPv6 day two years ago, but since then I haven't heard much about IPv6 in the news.

I would like to have a good understanding of what the change to IPv6 really means, and where we can expect problems.

Current situation

  • I guess all modern operating systems are IPv6 ready: OSX, Windows, Linux, Android, iOS (no problem to be expected for most people).
  • Internet providers: your connection to the internet, whether it's mobile or via cable or ADSL (my provider says it's completely IPv6 ready, but it's the only one this far in my country).
  • Routers/modems may be a problem (and as my provider says it's completely IPv6 ready, I suppose the router works too).
  • Hosting: I use a hosting provider for some websites that is not IPv6 ready. They promise to have this working this year. I guess many providers haven't got this working yet.
  • Home devices: digital tv recorders, tv with wifi, thermostats, wireless loudspeakers etc – I have no idea if they are IPv6 ready.
  • The internet at large: big websites like Google, Facebook – I guess they have this working.
  • Internet exchanges like AIX – this should work.

Some questions

  1. Home network: if my router is IPv6 ready, will it translate to IPv4 for devices that don't understand IPv6?
  2. Can these home devices still use IPv4 when the rest of the home network is IPv4?
  3. For sites that are still IPv4 only, will my computer or router switch automatically?
  4. When I open whatismyip.com, I see an IPv4 address. I believe I can ask my provider to change to IPv6, but I guess that will disable large parts of the internet for me – will it? Can I still send mail, will DNS work?
  5. When my provider changes to IPv6, will I still have an IPv4 address?
  6. Does this have consequenses for TLS certificates?
  7. With IPv6 NAT is obsolete I understand. Will this mean my wifi enabled tv is directly accessible from the outside? I guess the router firewall is still working, but now we can use a direct address from the outside?
  8. I don't live in Latin America and don't use Azure. But what if I go to Brasil right now. Will I notice it?
  9. Is there an easy way to test what works and what not without messing up the home network?

These are several situations and questions I can think of now. There are probably many more. What I want is a good picture of where we're standing now, and what we can expect to happen when this shortage becomes worldwide.

Best Answer

Answers to your questions:

  1. No, just because device supports IPv6 it doesn't mean it support IPv4<>IPv6 transition mechanisms - they're not part of IPv6 protocol specification. So, it may support translating traffic from IPv4 to IPv6 and vice versa but it needs to support mechansism like NAT64.

  2. Nodes communicate with the protocol of their choice, depending on the higher layer calls. If your browser points to a name, and the name resolves to IPv4 only, IPv4 will be called in to service it. If it resolves to both IPv6 and IPv4, IPv6 should take precedence, but a lot was done in recent years to make both calls simultaneusly and check which one is faster.

  3. You need to have node that is dual-stacked, so supports both IPv4 and IPv6 or have support of translating between protocols somewhere along the way. If your router supports it - fine, if your ISP supports it - it's also fine.

  4. You should see IPv6 as it should take precedence. If not, your IPv6 connectivity, at least to this specific site is broken. If you can use only IPv6 (you are not dual stacked) you can only reach around 4-5k prefixes around the internet, which is very small percent (out of 500k for IPv4). Normally, hosts are dual-stacked however, so you should be fine - using IPv6 for IPv6-enabled services, and IPv4 for all the rest.

  5. That depends on the type of the service your ISP provides. You may have private IPv4 assigned to your internet interface, and it gets translated somewhere at the ISP edge. You may have public IPv4.

  6. For SSL/TLS you're using names, not IPs directly. You should be fine.

  7. Yes, while there are still works to provide NAT services for IPv6, general idea about IPv6 was to stop doing NAT, and provide global connectivity. It means that with IPv6 assignment, your entire internal network may be directly reachable from other parts of the internet, if you're using IPv6 addresses from the Global Unicast space. For IPv6 you can use other types, like for example Link Local only, which would provide internal connectivity, but block ability to access from remote locations. Generally, you should filter the traffic at the edge of your network if you don't want the internet to access your resources/nodes.

  8. Unfortunately, I don't understand the question. Cloud services are usually OK with IPv6, Amazon at least is.

  9. Start from here: http://test-ipv6.com/

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