Transcript
False meme image that says “bad news ipv4 fans. linus torvalds has announced removing ipv4 support from the linux kernel after the maintainers of the network stack got into a fight over WHAT KIND OF HRT gives the best results. this incident will impact 5 billion people and will make 95% of all network equipment on Earth binnable.” with fake screenshots of the linux kernel mailing list a girl calling another one a slur from 4chan over HRT choices and Linus Torvalds saying he will drop IPv4 support and asking the maintainers to learn to shut the fuck up.
Can’t even attempt to learn it if my ISP won’t provide addresses though.
Not been able to use it to even try, but doesn’t IPv6 not have subnets at all? No 192.168.1.1 on your local network with a different public facing 85.136.52.142 (and with NAT444 you also have ISP facing 10.183.23.6). So does your ISP provide you a range of IPv6 addresses?
Correct, the ISP would assign you a /56 of public IPs that all share a prefix which you can slice and dice into however you see fit. All devices receive a publicly routable IP which your router/firewall would limit access to. So no running out of IPs ever, no network/IP collisions if you have to connect to another private network, etc.
Yes, your ISP provides you a large quantity of adresses. Not really, the adresses has several parts. Your ISP provides you with the prefix. Your devices complete the rest of the address automatically. You can also use a DHCPv6 server, but I don’t and some devices don’t support it anyway. Yes, all those adresses are globally routable, they are “Internet” adresses. You can still use locally routable adresses too if you want, called Unique local address (look it up on Wikipedia), but that requires manual configuration.
I don’t think unique local addresses require manual configuration. On linux at least, I get an
fe80::address derived from the interface’s MAC address even if there it can’t find any router. If the host receives a router advertisement, it will add a local address (the same suffix as the fe80 but with afd8b:something::/64)and the “internet”2003::.I’m not an expert and this may be just the configuration of my router, but all my linux installs automatically got these three addresses without manual configuration or issues.
You are confusing unique local adresses and link local addresses. Unique local adresses can only be configured manually or, in theory, with DHCPv6. On Debian, I edit the file “/etc/network/interfaces.d/<interface name>”:
This gives you: autoconfigured IPv4 address, autoconfigured (slaac) IPv6 address, an IPv6 unique local address, temporary IPv6 adresses (privacy extensions) and your IPv6 link local address.
That’s a link local address [0].
That’s a ULA [1]
This one is a globally routable address (Global Unicast Address, or GUA) [2].
As you observed, link-local addresses are generated completely independently. ULAs and GUAs are self-assigned using SLAAC or assigned by a server using DHCPv6 after your host has seen a router.
For a GUA or ULA to be assigned, the router or DHCP server has to have a prefix delegated to it. A GUA prefix would come from your ISP. A ULA prefix would be configured on the router itself. If yours has one without you setting it up, maybe it does that by default?
[0] https://en.wikipedia.org/wiki/Link-local_address [1] https://en.wikipedia.org/wiki/Unique_local_address [2] https://www.iana.org/assignments/ipv6-unicast-address-assignments/ipv6-unicast-address-assignments.xhtml
Yeah, I guess my router just decided on an ULA prefix on its own. Thank you for providing the right terminology and explaining how a host gets these addresses.
That’s SLAAC not a ULA
A single IPv6 prefix has 2^64 addresses
Why can’t you just use it on your local network? Don’t need ISP for that.