I am migrating my multi-subnet ipv4 home network to ipv6. Unfortunately, I am with an Internet provider who supplies only one non-but-mostly-static GUA/64 address. With or without Internet, I want ipv6 internally including my own DNS and DHCP and router advertisement services. My question(s) concern the best strategy to set this up with Internet access considering the following facts as I understand them:
A) ipv6 addresses are 48 bits global routing prefix, 16 bits subnet-id and 64 bits host-id, meaning my ISP has already precluded use of more than one network with their GUA unless I subnet into the host-id portion but doing so will break EUI-64 stateless autoconfiguration.
- Should I care since I will have my own stateful configuration (RA(s),DHCP,DNS)?
B) ULA's can be used to create internal networks that are not globally routable. Any interface can also be assigned multiple addresses, including both a ULA and GUA.
- Would doing so not imply two ipv6 networks per host, one internally routable and one externally routable?
- Any cordoning done by route, firewall or other on the ULA based nets would be effectively undone if I go back and add GUA's based on the single ISP provided net, correct?
- Would the default route for each host not need to be the external router internal GUA address with all ULA-based networks added to each routing table?
- Can dhcpv6 push routes and even if it can, will most random vendor devices like tablets or phones necessarily use them?
C) NAT66 is eschewed in most docs
- given the not-quite-static nature of the ISP GUA and the other issues as noted, wouldn't the overall best answer be to use ULA's internally and NAT at the external router?
