Native IPv6 not working

[M4tt]

I'm running a Zyxel NR7101 Modem with 5G connection in IP passthrough-mode with IPv4/IPv6-Dual Stack and an Asus GT-AX11000 on 386.7_2.

When connecting one of my two laptops or my PC, all runnig Windows 11, directly to my NR7101, they get an IPv4 and an IPv6-Address, so I assume, IPv6 should work in Native-Mode on my GT-AX1100 as well. My GT-AX11000 however doesn't get an IPv6 and doesn't populate IPv6 to clients, regardless if I set it to native or IPv6-passthough mode. Rebooting the modem and the router, shutting both devices down and wait for some time before starting again etc doesn't work. I also tested this with my old AC88U getting the same issue, so I don't think this is hardware related (and as mentioned IPv6 works fine when connecting any Windows 11-device directly to the modem).

My configuration in native mode looks like this (the prefix-length of /64 ist the correct prefix-length according to the FAQ of my provider):

This is the output of my IPv6-Log in native mode:

Any idea how to debug/fix this?

 

[heysoundude]

Step one - take the first 2 levels at ipv6.he.net/certification
Step two - https://www.asus.com/support/FAQ/113990

 

[Tech9]

Better provide the solution to the specific case.
Do you have a problem with that @heysoundude?

 

[Frank Monroe]

Why would you assume IPv6 on the ASUS will work in native mode when connected to the NR7101 just because your laptop received an IPv6 address when connected? With that information, I would assume just the opposite. If you are getting IPv6 addresses from the NR7101 that means its handling the address assignments. Unless the NR7101 and the network you are on also supports prefix delegation, and it sounds like they don't, the only mode that will work for you is passthrough mode.

In short, you probably want to set your connection type under IPv6 to Passthrough rather than Native or connect your devices to the NR7101.

 

[heysoundude]

Better provide the solution to the specific case.
Do you have a problem with that @heysoundude?

@Frank Monroe caught my drift, @Tech9 :

Why would you assume IPv6 on the ASUS will work in native mode when connected to the NR7101 just because your laptop received an IPv6 address when connected? With that information, I would assume just the opposite. If you are getting IPv6 addresses from the NR7101 that means its handling the address assignments. Unless the NR7101 and the network you are on also supports prefix delegation, and it sounds like they don't, the only mode that will work for you is passthrough mode.

In short, you probably want to set your connection type under IPv6 to Passthrough rather than Native or connect your devices to the NR7101.

 

[Tech9]

@M4tt clearly states it doesn’t work in Passthrough mode either. What your first two levels say? You have specific model numbers equipment in the equation. Guide @M4tt to the solution.

 

[Frank Monroe]

Does your provider mention they support prefix delegation? If not, passthrough mode is the only option outside of putting the ASUS in AP mode instead of router mode. Whats the goal here with the extra router? Who is the ISP? Also, when. you had your Windows system connected directly, what type of IP did you get? Were the IP's RFC 1918 (private IP addresses) or were they public?

 

[M4tt]

Does your provider mention they support prefix delegation? If not, passthrough mode is the only option outside of putting the ASUS in AP mode instead of router mode. Whats the goal here with the extra router? Who is the ISP? Also, when. you had your Windows system connected directly, what type of IP did you get? Were the IP's RFC 1918 (private IP addresses) or were they public?

When I connect my Windows systems, I get public IPv6-Adresses. IPv6 doesn't work in native as well as in passthough mode, my provider is A1 Austria. I think they support prefix delegation, as they mention providing a /64 subnet to endusers, but I'm not totally sure. I'm not using an "extra" router, the NR7101 is mounted on the roof of my house and set to passthrough everything like a modem, which works totally fine with Windows-devices directly connected as well as with IPv4 on the GT-AX11000, but not with IPv6...

 

[lman]

I had problems with native ipv6 and found a setting in TOOLS/WAN: Use local caching dns server system resolver. I changed that setting to yes and rebooted. Native IPV6 was then working.
You might see if that setting helps

 

[M4tt]

I had problems with native ipv6 and found a setting in TOOLS/WAN: Use local caching dns server system resolver. I changed that setting to yes and rebooted. Native IPV6 was then working.
You might see if that setting helps

Unfortunately, that doesn't fix my problem. It still works neither in native nor in passthought mode

 

[Frank Monroe]

Unfortunately, that doesn't fix my problem. It still works neither in native nor in passthought mode

When I asked earlier about your IPv4 IP being a pubic IP you responded with your IPv6 address. I'm not concerned about your IPv6 address. I would expect that to be public as that is the nature of IPv6. I asking about the IPv4 IP because the will give insight on how the NR7101 is behaving. So, is your IPv4 IP an RFC 1918 address?

 

[M4tt]

when I asked earlier about your IPv4 IP being a pubic IP you responded with your IPv6 address. I'm not concerned about your IPv6 address. I would expect that to be public as that is the nature of IPv6. I asking about the IPv4 IP because the will give insight on how the NR7101 is behaving.

My GT-AX11000 gets a public IPv4-Address I can connect to via OpenVPN etc (as NR7101 is set to IP-Passthrough, which works fine on Windows with v4 and v6 but only with v4 on my AX11000).

 

[M4tt]

These are the IPv6-specific settings of my NR7101, which look fine to me (and work with Windows connected directly). Maybe that helps?

The Mac-Address set below is the Mac-Adress of my Asus-Router (naturally I set that to dynamic when testing with Windows-clients connected directly):