Reliable replacement(s) for RT-AC66U

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New Around Here
Hi everyone,
I suspect that the 2.4Ghz radio in my RT-AC66U has finally bit the dust. No complaints though - It has performed almost flawlessly for an impressive 6 1/2 years! So I'm back to ask for advice before making a purchase (just as I did back then). I've read some posts and it looks like an RT-AX58U or RT-AX86U could be a good upgrade. I've kicked around the idea of a mesh (or multiple routers) in the past to improve performance in a few bad spots of my house, but wasn't keen on moving away from Merlin firmware features for an off-the-shelf mesh product. Here are my stats:

- 2700sq Ft
- 3 levels (2 floors & finished basement)
- About 22 clients total (3 rokus, tablets, phones, laptops, desktops, etc.) pretty usual stuff
- 2 adults / 2 children
- 200Mbit service (may upgrade some day - no hurry)
- Up to 8 devices in use at any given time
- Not much IOT (I have trust issues with Alexa/Google/Siri, etc)
- Although I do have a Honeywell smart thermostat - early model though, so I'm pretty sure they can't hear my thoughts. :)
- Streaming TV
- Kids remote school
- I work from home - lots of video conferences, etc - workplace VPN is the bottleneck there.
- No heavy file sharing, but periodic semi-large upload/download for work (1-2Gb)
- Plex media server
- Periodic remote desktop for work and personal use (helping family)
- Asus RT-AC66U running Merlin 378.56_2
- Motorola SB6141 Docsis 3 modem (still working perfectly from what I can tell)
- Most stationary clients in house are hard-lined (1 router, 2 switches)
- - - 8 port Switch next to router - all ports in use
- - - 8 port Switch in family room for TVs, game consoles, etc
- Very good signal strength over 2.4Ghz almost everywhere except kitchen and 1 bedroom upstairs

My preferences in general are stability and features ...I know they don't always live well together. ;)
Not afraid to pay for quality - $250-$300 if necessary, but money isn't burning a hole in my pocket either if that's overkill.
I intend to install Merlin again - was very happy with the improvements last time.
I will probably follow @OzarkEdge 's install notes - they look well thought out.
I plan to start with one router - but may consider adding a second in mesh mode (or AP?) if it will help my range without causing issues.
- Could I possibly use the old AC on 5Ghz or will that force the new AX to fall back to lower speeds?

Any comments or advice would be greatly appreciated - thanks in advance.


Part of the Furniture
Here are my thoughts on the aspects of your post that stands out to me.

I would agree that in your use case, the RT-AC66U is well past its prime. The best use for it going forward would be to upgrade it to either the latest Asus or the latest @john9527 RMerlin fork and use it as a Media Bridge for your furthest, wired capable, device needs (if you have a use for this in your current setup). Otherwise, I would not suggest using an RT-AC66U with any current router today. Note that it is not capable of AiMesh operation at all.

(The reason Media Bridge mode works well even for this older model is because we're turning many Wi-Fi clients into 'wired' clients with all the power and advantages that the 3x3:3 setup the RT-AC66U offers us. By making the router the single wireless 'client' and only using the LAN ports to connect devices to it).

RT-AC66U BIOS & FIRMWARE | Networking | ASUS Canada

You may need the following link to get the firmware updated from the incredibly outdated version you're using today. :)

You will have a much better experience if you can wire two RT-AX86U's together in AiMesh mode (vs. using them wirelessly). Is that a possibility? Don't forget that you can then use the LAN Ports of the routers for your wired clients too. (A wired AiMesh node is created when you connect an Ethernet cable to its WAN Port, BTW).

But you may find that a single (centrally placed) router today may be able to give you the coverage and throughput you need too. Even if you buy two routers, be sure to only unbox and test with one first. :)

As an overview, the routers to consider today are the RT-AX58U, the RT-AC86U, the RT-AX88U, and the RT-AX86U, in that order. For the fastest and most responsive network.

With any of the routers suggested above, the following process is what I would recommend to produce the most stable, reliable, and fastest network possible.

First, RMerlin firmware, of course. :)

The 386.1 Beta 4 (or Beta 4b, depending on the model) is very stable. The expected Beta 5 will likely be at the 'release' level, I anticipate.

New M&M 2020

M&M 2020 Specifics

How to Connect an AiMesh Node

Two AX86U Aimesh @2.5G Ethernet backhaul possible? | SmallNetBuilder Forums

Even with all the above, I would still be tempted to try getting the router you have working again. :)

Flash the @john9527 firmware as suggested above and then follow the suggestions below to get the router to a good/known state and one where it is using the expected defaults of the new/updated firmware you will have flashed on it.

Fully Reset Router and Network

The main reason to get the router working again besides saving some cash today is that the routers you want to buy are not available yet.

Those would be the Wi-Fi 6E routers which a prime example will offer not only RMerlin support but also up to 12 antennae, 12 streams, simultaneously and concurrently from a true Tri-Band, Tri-Radio design. 2.5GHz, 5.0GHz, and 6GHz bands. That will be an upgrade worth waiting/saving up for (I don't expect these to be cheap). I am also expecting the first examples of these (and hopefully with RMerlin's support) by this summer or fall.

Here are a few posts that may be of further interest to you too.

Is Wi-Fi 6 Worth It

Wi-Fi 6 Pt 2

L&LD | SmallNetBuilder Forums

Media Bridge Mode



Part of the Furniture


New Around Here
Thanks to all for the fast replies and information!

@bbunge - thanks for the recommendation!

@OzarkEdge - That's a pretty tempting deal for the AC86U - any idea why this model has so many low ratings on Newegg??? I checked on Amazon and it's 4+ stars there. Perhaps due to the issues discussed elsewhere here on the 2018 units?

@L&LD I'll take your advice on turning the AC66U into a wireless bridge - I needed a switch for a room in the basement anyway and it will work perfectly because it is precisely below my main router location on the main floor (= strong signal). Out of curiosity, I'll probably try to get the AC66U 2.4Ghz radio working again with the procedure you shared. I'm just committed to a new one on the chance I can start hitting the two dead spots in my house. :)

You mentioned AiMesh mode with two AX86U's - do the AC86U or AX58U support this as well?
(For $153, I could possibly justify getting two of the AC86U's.)

Last question: @OzarkEdge, you mentioned that the AC86U will have 20% more effective WiFi range than my AC66U - which would be perfect.
Would the same be true for the AX units?

If I could expect a small range boost over my current unit, the RT-AX86U at $249 feels like the sweet spot for me for price, performance, and future-proofing.

Many thanks for all your help!


Part of the Furniture
Yes, with the latest firmware available, AiMesh works well for the RT-AC86U and the RT-AX58U's too. My first on-site test in your case would still be with a single RT-AX86U though (the 'easily' better option).

Note that the single RT-AX86U (with the RT-AC66U as a bridge) is superior not only in hardware but also vs. 2x any other wireless Mesh system too (of the routers mentioned above). Be cautious of 'too much' Wi-Fi in your home. The overall experience may be worse than a single/main router.

If you can wire 2x RT-AC86U's in an AiMesh (main) and (wired node) setup, that too would work well for your home. I don't think wireless AiMesh would work as well but may be worth testing.


Part of the Furniture
@OzarkEdge - That's a pretty tempting deal for the AC86U - any idea why this model has so many low ratings on Newegg??? I checked on Amazon and it's 4+ stars there. Perhaps due to the issues discussed elsewhere here on the 2018 units?

Last question: @OzarkEdge, you mentioned that the AC86U will have 20% more effective WiFi range than my AC66U - which would be perfect.
Would the same be true for the AX units?

Some dings:

o Some early build AC86Us have died at about 24 months. Or had some radio issues. Judging from the traffic here... these are isolated early issues. Only time will tell about current product.

o Consumer product reviews have become less reliable and many consumers struggle with more difficult products like wireless routers. Try to read between the lines and ignore the dribble.

o Asus has been rolling out AiMesh firmware development across many models for nearly three years now. It's has been unusually rocky and demanding of anyone administrating their own network. Most consumers are not up for this. I am and I think it is worth the extra trouble, provided we get there... and we seem to be getting there.

The AX86U is a newer option, but will cost more. I have not used it but I suspect it has WiFi coverage similar to other new product and the AC86U. It also has provision for 2.5 Gigabit wired backhauls.



New Around Here
Thanks very much for all the information and thoughtful advice gents.

@L&LD - thanks again for all the detailed answers to my questions. This gives me confidence that the AX86U is worth the premium over the other (similarly) good suggestions considering my priorities.

@OzarkEdge - thanks for confirming my suspicion on issues isolated to early builds of the AC86U. You also bring up a good point that consumer reviews for some products (especially routers) may reflect their personal levels of difficulty, not just the product itself. I remember commenting to my wife while shopping for a router back in 2014 that it was a rotten experience, because I couldn't easily identify a clear winner across sites. It makes a lot of sense - routers require owners to be technically involved for the best experience they can offer and many consumers are just not up for that. It's a reminder to pay attention to not only patterns in product performance, but also patterns in the sources of those reviews. ;)

I've decided to go with the RT-AX86U as it seems to promise the right balance that I am seeking:
  • Increased range over my AC66U (and therefore the possibility to cover my whole house with one unit)
  • Support for Merlin firmware and features
  • A reasonable amount of future-proofing (short of waiting for Wi-Fi 6E)
  • Decent price point @ around 250.
Incidentally, There is currently an offer for a free Wi-Fi adapter with the AX86U:
ASUS RT-AX86U AX5700 Dual Band WiFi 6 Gaming Router

I'll report back when I have some experience to share (or more questions!).

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