Have you tried the settings with another web browers? Either swap back to the 3864AC modem or an early upgrade to the Asus modem/router. I have been using the asus RT-86UAC for little while now and it is going great.
Doesn't matter on the browser, can't change the DNS settings.
I tested a friends 3864v3(AC) but the reason for the upgrade to the 5366 was that the original 3864 is having issues so going back to it isn't an option. I could buy another router but the 5366 does a good job except for the DNS issue.
I've been thinking about changing over to secure DNS for a while but never had the motivation until now.
However I'm pretty sure ISP's aren't allowed to be hijacking DNS packets so I'll be talking to Optus and the TIO and relevant people during the week to see if a solution can be found if we don't get a response here in the next few days.
Interesting, the reason I mentioned browers is that I found the codes for the webUI can be different at times and some toggle/buttons dont behave as they should if the browser can't translate the codes.
Dont know much about DNS, are you saying that what ever dns setting you have on your computer get changed once it hit the 5366? Another word on my Network adaptor setting, I put my dns to 22.214.171.124, I send out a request (eg website), it goes to the 5366 and the modem send my request to Optus instead of 126.96.36.199?
Yep, that's the case. But it doesn't even have to be a valid DNS IP address. Put in pretty much any IP address, even a friends/works WAN IP address and the 5366 will still send it to Optus.
@WallyWalrick Interesting. Here are the tests I've done, please let me know if I've use the right method.
1. Modem DNS(A) as per Optus, Network Adaptor DNS (B) as per Modem , VPN (C) = Off. Result = OPTUS DNS
2. A as per Optus, B = 188.8.131.52, C = Off. Result = Google DNS
3. A as per Optus, B = as per Modem, VPN = On. Result = VPN DNS
3. A as per Optus, B = 184.108.40.206, VPN = ON. Result = VPN DNS.
So for me using the Asus RT86U, leaving the DNS on the modem as per optus doesn't change my DNS, changing the setting on my network adaptor and VPN affect where the DNS is send to.
Are you checking the DNS server or the route? Because the packet path will always go via Optus.
Definately checking the DNS server.
1. If you put an invalid static DNS server and flush the DNS cache you shouldn't be able to resolve DNS at all. With the 5366TN I can still access all sites as normal.
2. I have access to an external DNS server that logs my DNS requests. Using the 5366TN that logs stay empty (obviously using that DNS IP within Windows 10 networking)
3. Using router DNS checkers like the one you linked, they all give me an Optus DNS IP as my DNS server, not the one I listed.
All tests included closing all browsers, clearing cache of both the browser and the DNS cache.
Also if I use the old F@ST3864...
1. Can't access sites - DNS error
2. the log fills up with DNS requests
3. DNS checking websites show the same IP that I have used. eg. Not an Optus DNS
EDIT: Just to add, if I used a VPN from my computer the result would likely be the VPN DNS as a VPN is encrypted so the 5366TN wouldn't know how to intercept the DNS packets.
@WallyWalrick Thanks for the update. There might be some firmware restriction or glitt on the 5366, hopeful it will be resolved when they update the firmware. For me the DNS setting behave as it should on the Asus and 3864. Unfortunately, I do not have a 5366 modem to test and play with. I will try to buy one from Optus and see if I can replicate the issue. Cheers.