I got two servers with public IPv4 and (now) IPv6 addresses. They have a VPN to do stuff like MySQL replication. With IPv4 I just took a RFC1918 range ( and if you access the server via that range, it went through the VPN. With IPv6 everything has a globally unique address without NAT. How would you assign addresses to the endpoints? I got on each side a /48 subnet.

I see the following possibilities:

  1. Use a private/documentation/... IPv6 address
  2. Somehow route the traffic to the public IPv6 address through the VPN

How would you do it? VPN is tinc.

  • Documentational space is never a good idea, it has one very specific purpose. What endpoints are you talking about, the clients? Or are those servers connected with eachother through a VPN?
    – Teun Vink
    Aug 12, 2014 at 19:29
  • The server are connected with eachother.
    – Lorenz
    Aug 12, 2014 at 19:29

1 Answer 1


General rule of thumb: never use documentational space. It has a very specific purpose, don't ever use it for anything else or you'll regret it at a later time.

If these two servers only need to talk to eachother and don't require any other connectivity for the given IPv6 addresses I'd use ULA space: pick a somewhat random /64 from within fd00::/8 and use that between the servers.

  • 3
    @Aragon0 Don't just use fd00::/8 or you'll defeat the whole purpose. Use a generator to pick a random range within that block. Aug 15, 2014 at 19:41
  • @MichaelHampton Thank you for pointing that out! Luckily I haven't had the time to set it up yet, so I will use the generator.
    – Lorenz
    Aug 15, 2014 at 19:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.