Does ddns-start get passed IPv6?

[el_pedr0]

I believe the built-in ddns scripts can now update IPv6. On an IP change event, does the custom ddns-start script get passed a IPv6 value (similar to how ${1} is the IPv4 address) or have access to an environment variable with the IPv6 address?

 

[Crimliar]

I think it depends on the router. Certainly on the GT-AX6000 here the inbuilt routines will not update the DDNS for IPv6 as the address needs to be pulled from BR0 and not PPP0. Of course, if you write your own script you can have it update the IPv6 address however you choose to do it (there will be no IPv6 variable passed to the routine so it's DIY), and not ticking the "IPv6 Update" radio button is not going to throw an error into the logs!

*While I maintain that I'm lazy, I do currently use a custom script to update my main domain using DynV6, but I have a secondary domain being updated using Hurricane Electric DDNS! Actually, that is the lazy way - other than the need to use 2 DDNS services!

 

[el_pedr0]

Thanks. I've got a custom script (originally because I needed to update 2 ddns services, but that's borked now by a move to a CGNAT ISP ). However I do have designated IPv6 prefix. So I'm embracing the future and adopting an IPv6-first mindset.

I can pull the IPv6 from within the ddns-start script using

IPv6=$(ip -6 addr list scope global $device | grep -v " fd" | sed -n 's/.*inet6 \([0-9a-f:]\+\).*/\1/p' | head -n 1)

(hat tip: alphabt)

I just didn't want to miss an even simpler way if one existed.