IPv6 Router Priority?

iPanda032 · Feb 6, 2023

Hi so I'll try to describe what was happening the best I can. Hope someone might be able to offer an explanation. I was having an issue with few apps having really long log in times. Like Roboform seemed to take like 30-40 seconds to login. Battle.net was not logging either. My router is ASUS RT-AX82U. I manually set DNS to 1.1.1.1, 1.0.0.1 for IPv4. But I let IPv6 stay default to whatever my ISP was giving and didn't think much of it. And it hadn't seemed like it would cause an issue. I've never really set IPv6 DNS manually before this and I never had an issue, But after changing the IPv6 addresses to be also the 1.1.1.1 version. That seemed to resolve my long log in time. My question is does the router prioritize IPv6 over IPv4 dns? Or does it depend on the website you're trying to resolve to? I haven't had this router for very long so I'm wondering if this model has peculiar behavior? Before I had Netgear and that worked fine for years until one day it just up and died on me. Or was this just a coincidence from changing the IPv6 and something else was happening I should look into? But my network seems fine now after changing IPv6 address. So that's odd to me. Honestly I'm kinda annoyed with this router as it has some quirks that just seemed to not be optimal. Like QoS setting seemed to throttle my network. To me a while to figure that one out.
Anyway, appreciate any insight. And I'll give more details if needed.

OAT · Feb 6, 2023

Your OS can prioritize :

Registry key;
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\
Name: DisabledComponents
Type: REG_DWORD
Prefer IPv4 over IPv6 Decimal 32
Disable IPv6 on
all tunnel interfaces Decimal 1

It is not recommended to disable IPV6 but the Decimal would be 255

iPanda032 · Feb 6, 2023

Oh I didn't think about Windows setting Priority for DNS too. Is the default behavior to choose IPv6 over IPv4? Since I seemed to have resolved it by changing the DNS address for both 4 and 6 that's no longer an issue. I just wanted to understand if that was what's happening? Windows, Router, or Modem prioritizing DNS address. Quick google Search, seems Windows prioritizes IPv6. Which is fine I guess. But it's strange that I started having issues only recently after updating my hardware from 10th Gen To current 13th GEn Intel platform. Unless that too was a coincidence. I kept my storage the same. Just reactivated after installing all the new drivers. Everything seemed fine until few days later.

OAT · Feb 6, 2023

Every device is configurable

iPanda032 said:
Is the default behavior to choose IPv6 over IPv4?

No the sub key is simply not there, letting other devices down the chain take care of it.
It is not only for name lookup but every packet will go thru the chosen protocol.
If you want to read about the other options:

IPV6 config

FrancoDT · Feb 6, 2023

iPanda032 said:
I've never really set IPv6 DNS manually before this and I never had an issue, But after changing the IPv6 addresses to be also the 1.1.1.1 version.

Now I'm confused doesn't IPv6 have to use IPv6 addresses which are 2606:4700:4700::1111 and 2606:4700:4700::1001