Guest Network Pro in FW 3006 - different default DNS Server than in FW 3004?

[Rici]

Hi,

After I upgraded my Asus RT-AX86U Pro from firmware 3004 to the new 3006, a couple of my devices which are connected to my guest network #1 no longer can connect to the Internet.
Unfortunately, I haven't checked and made a note which DNS Server the guest network clients were using with the former 3004 firmware...

What has changed - as FW 3006 seems to use a different default DNS Server than FW 304 for the guest network?

 

[bennor]

Did you assign DNS servers in the Guest Network Pro Profile Advanced > DNS Servers section? Or did you setup DNS Director to route your Guest Network Pro profile clients? Does your Guest Network Pro Profile use the same IP address subnet as the main LAN or does it use a different IP address subnet (like 192.168.52.1)?

PS: The Guest Network Pro feature is a major change over the prior Guest Network section. Also note that if you had YazFi installed under 3004.x firmware, YazFi is not supported on 3006 firmware. And from the 3006 firmware change log but it likely doesn't apply if you are having an issue on the first Guest Network Pro Profile entry:

3006.102.4 (10-May-2025)
- NOTE: If migrating from a 3004 firmware, only the first Guest
Network will be migrated - any additionnal GN must be
manually reconfigured.

 

[Rici]

Did you assign DNS servers in the Guest Network Pro Profile Advanced > DNS Servers section?

Now I did, since my guest network clients lost their internet connectivity and I was investigating what could have caused this.
It is the first GN so I knew it was not the issue. Also, no YazFi installed.

What was the default DNS server for the guest network of FW 3004? The one from the router?
I have not written this down before upgrading to FW 3004.

 

[bennor]

What was the default DNS server for the guest network of FW 3004? The one from the router?

If I remember right (but I might be wrong) the 3004.x firmware Guest Network (when not using YazFi) would use the LAN DHCP Server DNS address if one was assigned. If none were assigned or if one configured the router to be included with the DHCP DNS address, then it would use the router and what ever the router's WAN DNS servers were configured to.

You learned a valuable lesson. Always try to keep a file/document you can refer back to with your router's settings just in case something like this happens. Because there is a major difference between 3004 and 3006 some recommend performing a factory reset after updating to 3006 and manually configuring the router (not importing a saved router.cfg file).

 

[bbunge]

The easiest thing for you to do is to delete the guest WIFI and create it again. This will set the networking on the guest to its defaults. For example, if the setup not using the router subnet is used the IP addressing will be something like 192.168.52.0/24 and the DNS and gateway will be 192.168.52.1. the "52" will be the same as the VLAN number.
If I remember correctly, the 3004 firmware assigned the guest networks thusly: first VLAN 101, IP 192.168.101.0/24, gateway and DNS 192.168.101.1. The second was 102 and the third 103.
The 3006 firmware allows you to manually assign a VLAN number with a corresponding IP range.
AS I said earlier, delete the guest network and set it up again. Better yet, factory reset the router and manually configure it. You will be much happier.

 

[Rici]

Thank you, @bbunge !