How to set static IPV6 mapping for LAN interface

[Truxi]

Hello,

I'm seeking for help as I can't figure how to do this.
I have:
- ISP providing /56 and delegating /64
- WAN in DHCPv6
- LAN Track WAN

Everything works fine ! I have IPV6 connectivity on all my LAN it's great.
But I would like my LAN interface to be always the same IPV6 (like it is for my IPV4).
Unfortunately I cannot do that since I'm in "Track Interface".
I'd hope I could do a static mapping but AFAIK I can't do it from Admin console.

Looking for help, thanks.

[Patrick M. Hausen]

If your ISP gives you a static prefix, you can just set your LAN to static configuration and pick an address to your liking. Track is not mandatory in this case.

[Truxi]

Thanks for your help.

Unfortunately I don't have static prefix, it's going to change on reboot of my ISP device.
I'm a bit clueless on how I should advertise my DNS server IPV6 to my internal devices if it's going to change at each reboot of my ISP device.
I'm curious how people are doing.

[marjohn56]

If your IPv6 PD is going to change then just leave everything as tracking. If your address allocation changes then that will be advertised to your internal LAN by the dhcp6 server and radvd.  If you want a server on your LAN that can be accessed from the WAN then use a dns provider that supports dynamic DNS such as Cloudflare and use DDNS to update it. I've been there and got that t-shirt.

[meyergru]

True if the OpnSense itself is the DNS server. If another server, like pihole or something of that sort is to be announced, you can either use its IPv4 address or you could resort to ULA addresses on top of the routeable GUAs,

[Truxi]

For context I have AdGuard plugin installed and my OPNSense LAN interface is exposing AdGuard DNS server.

True if the OpnSense itself is the DNS server

I'm sorry but I must be missing / misunderstanding something or that must be because I'm not using integrated Unbound DNS Server,
 but how can I advertise dynamically my LAN interface IPV6 to my local IPV6 devices via DHCPv6 ?

I see I can input a list of DNS servers either in router advertisement or in DHCPv6 but it's going to be manually input of the current LAN IF IPV6, on my next reboot of ISP device it won't be the same.

[Truxi]

use a dns provider that supports dynamic DNS such as Cloudflare and use DDNS to update it

I see thanks for the idea though I just learned about ULA and wonder if I couldn't get away with it.

[Truxi]

Gave it a try with ULA, I'd set a virtual IP to my LAN and it worked great actually !
Didn't think of it but this is exactly what I needed as it's only for my private network.

Thanks for your help !