Hacker's ramblings

UUUJEA!

Com Hem has been rolling out a native SLAAC/DHCPv6-based IPv6 to it's entire customer base, and they took a very important step 2 in their project. They started honoring Prefix Delegation -requests! To a non-network person that means absolutely nothing, but to a network administrator that is really a game changer!

Normally I don't use much of the features my Sagemcom cable-TV -router has, it's just set to bridge:

Since I failed earlier to get a prefix from my ISP, I was toying around with my router and set it to router-mode, and to my great surprise:

The thing issued my LAN a /64 IPv6-network! Nice.
After putting everything back and eye-balling the DHCPv6 lease file on my Linux-router:

lease6 {
  interface "enp1s0";
  ia-pd c4:d0:0a:85 {
    starts 1515858667;
    renew 302400;
    rebind 483840;
    iaprefix 2a04:ae00::/56 {
      starts 1515858667;
      preferred-life 604800;
      max-life 2592000;
    }
    option dhcp6.status-code success;
  }
}

Yes, it contains an ia-pd -section! The iaprefix from the file is mine, only mine, my precious address space!
I have no idea how long they have been honoring my PD-requests, but on December 17th they didn't.

A generally accepted IPv6-deployment principle is to follow RFC 5375 [IPv6 Unicast Address Assignment Considerations]'s suggestions and issue a minimum of /64 (18E IPv6 addresses) to customers. Since this /64 is completely useless for your own LAN, a second suggestion is to issue a /48 (1,2 million E IPv6 addresses) or /56 (4700E IPv6 addresses) prefix for consumer's own LANs.
Note: 18E is SI-prefix for exa, aka 10^18. A /64 IPv6 network has 18,446,744,073,709,551,616 unique addresses in it.

The numbers are astronomically big and it's quite easy to get confused and lose the perspective what they actually mean. A more concrete approach is, that by being issued a /56, I can now split my prefix into 256 separate /64 networks as I please. It's not like I need 256 LANs, I'm totally happy get even 1 of them to work!

Now I have my hands full to configure and test everything on my LAN. I need to make sure, that native-IPv6 works for wired and wireless toys I have here.