How to use the entire delegated prefix for SLAAC?

[trick77]

I have a very simple IPv6 setup. No VLANs, no prefix delegation to other routers. I request a prefix from my ISP, get a (random) ::/56 assigned and use Track Interface on the LAN-side which chops the /56 into /64s depending on the prefix id. A static /56 DHCPv6 configuration on the LAN side breaks every time I'm getting a new prefix. That's why I'm only using SLAAC via an unmanaged RA in the LAN.

Now, since I like the Privacy Extension very much, I would like to make the entire /56 available for SLAAC on the LAN side instead of just one /64. How could I do this with a non-static/stateless (redarding a specific IPv6 prefix) approach?

I already tried with 0 in "Prefix Interface Site-Level Aggregation Length" (instead of 8 ) which did not work in combination with the Track Interface option.

[franco]

Keep in mind SLAAC is only /64 anyway. You could assign multiple /64 but it's not supported by the config.

You can distribute part of the prefix via DHCPv6 PD to further downstream routers, but all they do is break it up and deliver /64 networks again via DHCPv6 NA or SLAAC.


Cheers,
Franco

[Patrick M. Hausen]

Every broadcast domain is a /64 in IPv6. One size fits all. That is the size of the legacy (IPv4) Internet squared, already.

[trick77]

Ahh too bad
Thanks guys!

[Saarbremer]

See https://docs.opnsense.org/manual/ipv6.html#track-interface

This mode uses a WAN DHCPv6 interface to assign a single /64 network to your LAN interfaces.

I don't get why 2^64 IPs should not be enough to obfuscate your IPs.

[trick77]

It's not about the size of the wave, it's about the motion of the ocean

That's why I mentioned the Privacy Extension in my post. I want to randomize all address over the ocean, in this case the /56. Addresses in a /64 are regarded as coming from the same source when it comes to tracking, like a /32 in IPv4 terms. Using the full /56 would make it a little harder to track. Why waste them.

[Bob.Dig]

Why waste them.

Privacy Extension do only work on the same /64-prefix. You, as a beginner, shouldn't try to invent things. And for me, the whole /56 changes on a daily bases. There is no need to have more than one /64 involved with Privacy Extension anyway.

[Saarbremer]

Tracking can use IP adresses but it is more effective using different methods. Mobile devices change their prefixes (between wifis and cell service) over and over again. Doesn't help them. :-)

[trick77]

You, as a beginner

LOL love the spirit here!

[Monviech (Cedrik)]