RT AX89X DNS Issue with Firmware 3.0.0.4.386.22790

[oldguy]

I have been having spurious network disconnects with iPad, iPhone, Mac Book Pro, Nest Devices and Wemo IOT devices.

I have an RT AX89X with 3.0.0.4.386.22790 firmware and a GT AC5300 AI Mesh node with 3.0.0.4.384.82037 firmware connected by Ethernet backhaul.

Given the problems got worse during the recent Google outages, I decided to change the primary DNS servers for IP4 and IP6 to Cloudflare from Google.

IP4 – 1.1.1.1
IP6 - 2606:4700:4700::1111

I kept the Google DNS servers as alternate

IP4 – 8.8.8.8
IP6 - 2001:4860:4860::8888

After the change, I checked the DNS settings on my iPad and found that the google was the primary server with the RT AX89X as the alternate.
Going back to the RT AX89X settings I noticed the drop down menu with a wide range of options, which unfortunately did not include either Cloudflare or Quad9 defaults.

@ASUSWRT_2020 is this expected behavior when not selecting DNS servers that are not in the dropdown list?

I have forced manual DNS server address’s for my iPad, iPhone and Mac Book to see if this continues to be a problem, whilst leaving my better half’s devices with the default automatic settings.

For my Wemo devices, however I have to live with the DNS servers provided by the router.

 

[oldguy]

Looks as though there is a DNS setting in the LAN DHCP configuration page that I missed

Not sure why there would be a DNS setting in the WAN page and on the DHCP page, anyone have any thoughts?

 

[OzarkEdge]

Looks as though there is a DNS setting in the LAN DHCP configuration page that I missed

Not sure why there would be a DNS setting in the WAN page and on the DHCP page, anyone have any thoughts?

If you hover your cursor over a setting label and select on ?, a pop-up help message will explain things to you.

The LAN DHCP DNS configures client DNS. Leave this blank for DNS requests to be processed by the router.

The WAN DNS configures router DNS. Configure this to use ISP DNS or your own preferred DNS.

OE