I’m having some trouble thinking outside IPv4 and to find out what is the best way to (fully) enable IPv6 in our small company network.

(Motivation: gather knowledge, make port forwarding obsolete, long run IPv6 only)

Current situation

I think I’ll start with describing our current network setup (If I’m missing something essential here, please feel free to ask; subnets and name are fictional):

Router: FritzBox 7590 (internal DHCP deactivated) IPv4: 192.168.12.250

DHCP & DNS 1: Windows 2012 Server IPv4: 192.168.12.5

DHCP & DNS 2: Windows 2012 Server IPv4: 192.168.12.15

DHCP Range: 192.168.12.100 – 192.168.12.200 Some reserved IPs for devices which have A record in the DNS Server. Some internal servers which have fixed IPs and an A record in the DNS Server.

Webserver: 192.168.12.60 Port forwarding to Port 443 is configured in Router, external domain on something like interal.company.com (dynamic DNS with http://www.nsupdate.info)

The DNS domain is something like company.local

Where I am now

I think it’s a rather small setup, so I thought enabling v6 shouldn’t be that hard.

We get a (non-static) IPv6 address from our internet provider: 2003:e4:feef:feef:e228:6dff:fe6f:56ff

And a IPv6 prefix. 2003:e4:ffff:ffff::/56

After enabling v6 on my machine and the router I ran into the first problem: DNS requests to internal hosts couldn’t be resolved.

This was because the router announced external IPv6 DNS servers which were prefered by my DNS client. To resolve the issue I enabled IPv6 on one of the DNS servers, took the Link Local Unicast address, and configured it as static IPv6 address. (DNS 1: fe80::893:c9d6:bb08:f46) I configured this address as IPv6 DNS server in the router.

This fixed the issue, but I’m not shure how to preceed.

Questions

1. Why is the router IPv6 address outside our IPv6 prefix?
2. Should I be using a Unique Local Unicast address instead of the Link Local address for the DNS server(s)?
3. What would be a sufficient distribution scheme for local v6 addresses?
4. Shall I enter prefixed or local addresses into the DNS database? If prefixed – how are they changed when the prefix changes?
5. For the webserver: Should it have a fixed address after the prefix so my external dynamic DNS provider (nsupdate.info) can be updated by the router? How do I accomplish that?
6. What to to with the reserved addresses which have DNS records, how do I transition these to v6?
7. I didn’t mention we are also running an Active Directory domain. Does this change anything?

Thank you very much for reading!