Billion UK Forum

nightcustard wrote: ↑Sun Sep 05, 2021 10:49 am I have an 8900AXL2400 running firmware 2.52.d50

I have three 2.4GHz wireless APs: Main (client isolation off); 2x guest APs, one with clients isolation.
I also three 5GHz wireless APs: Main (client isolation off); 2x guest APs, one with clients isolation.
In Interface grouping I have Groups Isolation set and three groups: 'Default' containing ptm0.1, P1, Main WiFi 2.4G and Main WiFi 5G; 'Not Used' (as its name implies): P3, P4 & P5/EWAN; 'IoT' containing: both Guest WiFi 2.4G and both guest WiFi 5G.

My problem is all 5GHz APs are reported by clients as having no internet. All three 2.4GHz APs have internet access.

I'm sure the issue is DNS server related but it's defeated my attempts to get a working configuration. I have a PiHole DNS server on my main network (the 'Default' interface group) which provides DNS look-up for clients on the 'Default' interface group. Clients on the 'IoT' interface group also have their DNS lookups provided by the PiHole even though the PiHole is in a different interface grouping. I presume this is because they query the router for DNS lookups and the router queries the PiHole on their behalf.

The router's DNS settings are as follows:
LAN - 'Use Router's setting as DNS Server' unticked and the IP address of my PiHole in the 'Primary DNS server' box.
WAN (ptm0.1) - 'Obtain DNS' is set to 'Use Static DNS' and the 'Primary DNS' is set to my PiHole's IP address.
'Advanced Setup/DNS/DNS' - 'Use the following Static DNS IP address' is ticked and the 'Primary DNS server' is set to my PiHole's IP address.
'DNS Proxy' - Enabled, 'Host name' and 'Domain name' are both set to 'home.gateway'
'Static DNS' - not defined (although I have defined this previously with no change in Main 5G AP internet status)

If I change the LAN DNS setting to 'Use Router's setting as DNS Server' ticked, the main 5G AP has internet access but can't access IPs on the LAN.
[Edit]: Under these settings, the main 2.4GHz AP has both internet and LAN access.

The issue has survived several firmware upgrades and the only home-grown option I think I have left is to nuke the current settings with a factory settings restart and start afresh. I really don't want to do this as I have a shedload of settings to enter with a divorce in the offing if my partner's internet access is disrupted for too long .

I'm sorry this is a bit of long one but if anybody has any suggestions to sort this, I'd be very grateful!

nightcustard wrote: ↑Thu Sep 09, 2021 2:17 pm Well, having restarted the router with factory settings and then configuring the minimum settings needed to get my network up and running, I discovered the PiHole DNS settings are probably a red herring.

With more than one interface group, it appears the router only successfully resolves both LAN and WAN addresses for the main 5g AP if a guest 5g AP remains in the 'Default' interface group, alongside the main 5g AP.

What I did:

I removed the PiHole DNS server from the game by only testing the router with the standard DNS server settings (ie) LAN: 'Use the router's setting as DNS server' and WAN Obtain DNS: 'Use WAN interface',

With all LAN interfaces in one 'Default' interface group, the main 5g AP could resolve LAN and WAN addresses.

With a second 'IoT' interface group, containing both guest 2.4g APs and both guest 5g APs, the main 5g AP could only resolve WAN addresses.

Removing that interface group and adding a new one containing both guest 2.4g APs and only one of the guest 5g APs, leaving the other guest 5g AP in the 'Default' group, the main 5g AP could resolve both LAN and WAN addresses.

I created a third guest 5g AP (a 'dummy'), removed and created the second interface group, this time containing both guest 2.4g APs and both of the original guest 5g APs, leaving the 'dummy' guest 5g AP in the 'Default' access group. The main 5g AP resolved both LAN and WAN addresses and the functionality survived a router restart.

I can't be absolutely sure about the above as I found some interface groupings appeared to work when the change was made but the functionality didn't necessarily survive a router restart, so I spent quite a bit of time testing various configurations each followed by a router restart and am still not 100% sure my conclusions are sound(!).

What's also bothersome is the issue started for me as 'no internet' problem on the main 5g AP. After wiping the settings and starting afresh, it turned into a 'can't resolve LAN addresses' issue on the main 5g AP. It's quite possible I was dealing with two issues, one resolved by the factory reset and the other persistent. I'm perplexed but happy as I now appear to have a working 5g network....

Hopefully this might help anyone with similar issues and I'd be interested in any comments.

[Edit 1 hour later]: Murphy's law has hit! I changed the 'dummy' 5g AP to 'Hide SSD' and subsequently lost both LAN & WAN connectivity on the main 5g AP. I got WAN connectivity back by toggling the LAN DNS setting from PiHole to Use router's settings and back but appear to have lost LAN connectivity. I guess the lesson here is you shouldn't expect fudges to work!

Back to requesting help please.....