Today in our newest take on “older technology is better”: why NAT rules!
It should only be needed if your ISP is brain-dead and only gives you a /64 instead of what they should be doing and also giving you a /56 or /48 with prefix delegation (I.e it should be getting both a 64 for the wan interface, and a delegation for routing)
You router should be using that prefix and sticking just a /64 on the lan interface which it advertises appropriately (and you can route the others as you please)
Internal ipv6 should be using site-local ipv6, and if they have internet access they would have both addresses.
My ISP does this right (provides a /56 for routing), but unfortunately both are dynamic and change periodically. Every time I disconnect and reconnect from the internet, I get a different prefix.
I ended up needing to have ULAs for devices where I need to know the IPv6 address on my network (e.g. my internal DNS servers).
Indeed, that’s correct ula usage, but shouldn’t need nat rewriting. The global prefixes just need to be advertised by RA packets
I use openwrt on my home network which uses dnsmasq for dhcp. It can give a static suffix which just works with the global prefix on the interface and the site local / ula prefix it uses
Hurricane Electric gives me a /48.
Site-local ipv6 would work here as well, true. But then my containers wouldnt have internet access. Kubernetes containers use Ipam with a single subnet, they can’t use SLAAC.
Point is, you should be able to have them have both. Or stick a reverse proxy in front that can translate. Unless they’re somehow meant to be directly internet reachable the public addresses could be autogenerated
Full disclosure though I don’t know anything about kubernetes.
Yeah, I wonder if there’s any proposals to allow for multiple IPV6 addresses in Kubernetes, it would be a much better solution than NAT.
As far as I know, it’s currently not possible. Every container/Pod receives a single IPv4 and/or IPv6 address on creation from the networking driver.
64 for the wan interface
Nitpicking, but the address for the wan interface wouldn’t have a prefix, so the host would just set it as a /128 (point-to-point)
And if you want static ips either use dhcp6 or disable the randomisation of eui64 addresses
I have static IPs for my Kubernetes nodes, and I actually use DHCPv6 for dynamic dns so I can reach any device with a hostname, even though most of my devices don’t have static IPs.
The issue is those static IPs are tied to my current ISP, preventing me from changing ISPs without deleting my entire Kubernetes cluster.