I just installed the Asus XT8 this evening replacing my 4 year old Orbi AC 3000 which constantly was having the DNS issue. I have to say I’m not impressed - at all. I ran a battery of speed tests prior to installation with the Orbi at various points and once the Asus was online ran the exact same tests. The speeds are roughly 100 MB slower with the Asus at almost all points. Tech details I have ATT gig fiber running with the BGW 210 in router mode and the Asus in AP mode. Was planning on bypassing the 210 and allowing the Asus to act as the router but wanted an apples to apples test. However now I’m tempted to return the Asus and get the Orbi AX 6000. As an aside I’m a network engineer with many certs to my name so I’m not a newbie.(Nor am I trying to brag just for reference) Any tips or tricks on what I’m missing or can do would be appreciated!
I had similar issues with the exact same setup as yours and the same ISP. I ended up buying an ASUS GT-AX11000 as my main router and reconfigured my XT8’s as nodes, made sure to switch my WAN connection from the WAN port to the 2.5 GHz port (and changed the router GUI settings in the Dual WAN menu to recognize this), installed the most recent firmware, and now I get WAN-side speeds through the router’s speed test in
excess of the gigaspeed limits quoted by AT&T.
My first recommendation (which given your credentials is perhaps unnecessary) is to make sure to perform the IP Passthrough setup on the BGW with a laptop or desktop connected directly to the router with no other clients attached anywhere in the chain during the process.
Other than that, I would at least suggest trying the 2.5 GHz WAN connection (under the web GUI go to WAN settings, then “Dual WAN”, and change “primary WAN” to the 2.5 GHz port). I use a CAT 8 cable for the WAN connection which I fully acknowledge is overkill. ASUS also just released a firmware upgrade, which is working great for me—I would install that.
I have made a few tweaks on my wireless settings as well, but they shouldn’t affect WAN-side speeds. I did find that choice of servers in the Ookla test greatly varied my results, but as I said I am getting speeds above 1000 mbps on at least two servers.
I also have noted the following—enabling multicast in the IPTV settings, which is required for me to run my Roon audio software, completely confounds my WAN-side speed test results, and I’ve proveably demonstrated that this is an artifact. When it’s on, my WAN speed results drop by about 300 mbps, but this has no effect on the speeds I obtain in my network clients, which remain intact. You could probably explain why this occurs better than me!
Lastly, I must say that despite the extra expense involved, my current setup with the AX11000 (NOT the AXE11000) as my main router, with two XT8s as nodes, is the fastest and most stable network configuration I’ve ever had, and I’m running 55+ clients. I was previously running a Linksys Wi-Fi 6 Velop mesh with four nodes, and this ASUS setup is unequivocally superior. Best of luck!