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3 RT-AC68U's: AP Mode or AiMesh?

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darkgiants

Occasional Visitor
I have three RT-AC68U's that serve my internet needs perfectly fine for the last few years, and I believe they should continue to do my internet needs fine for the foreseeable future. However, I am exploring two options for these three routers:
  1. Option # 1: One RT-AC68U setup as the primary router, other two RT-AC68U's setup in AP mode with WiFi SSID's having the same name and password but setup on different channels to promote better roaming.
  2. Option # 2: Setup one RT-AC68U as the primary router, and the other two RT-AC68U setup as AiMesh nodes, having AiMesh handle all the setup (no configuration of SSID channels, etc...).
I have tried both options and I don't see any performance issues, however, when I do use my entire router in AIMesh, I have noticed the RAM on the primary router slowly creeps up within a few days, whereas within a week or two, the RAM is near ~95% usage. This prompts a reboot to stabilize everything. I never noticed this issue when using Option # 1. I am also using the latest version of the Merlin firmware (368.11). I also see a pop-up of NVRAM usage being high, however, I am not sure if this is seen as a concern.

Therefore, I was wondering if there is any benefit to using AiMesh with the RT-AC68U? Is it more taxing on the hardware since this is older hardware to have it in this setup, and instead using the other two routers in AP mode easier than the primary router? Also, from a performance level, does setting up via AP Mode versus AiMesh provide better performance in general? I can't see any differences from regular speed tests, but not sure if having my SSIDs on different channels is beneficial for my setup.
 
Whatever works best for you. It is recommended to have the AiMesh nodes on Asus factory firmware. For the router RAM issue do not use Samba and/or set up a swap file. The NVRAM issue could be a show stopper and I believe that issue has been addressed elsewhere in these forums.
 
Option 1. Different channels do not promote better roaming.

You may find that a single AX class router may be able to replace your 3x, 10 year old routers, while giving better performance.

Not only will you enhance your online experience, but your network will be safer too.
 
I appreciate all the comments! I will give try converting the two nodes to ASUS stock firmware to see if that potentially helps resolve any of the RAM issues because otherwise, there is no SAMBA or swap file that I have configured.

As for the NVRAM, I have tried one of the scripts I found on the forum, and while it clear up a significant amount, I noticed after a reboot, the NVRAM goes back to the same amount as previously before. Not sure what's not clearing the NVRAM permanently?

And I have been considering upgrading to a new generation router, but I honestly am happy with this router as my internet speeds and network work perfectly fine. The reason I have three nodes is because I have detached areas around my home which made it easier to install a node separately (hardwired). I figure as long as the router is continuing to get updates, and I have no need to increase my internet speeds, I can carry on with these routers....
 
As for the NVRAM, I have tried one of the scripts I found on the forum, and while it clear up a significant amount, I noticed after a reboot, the NVRAM goes back to the same amount as previously before. Not sure what's not clearing the NVRAM permanently?
It is well mentioned issue that the various script or code methods to clear the NVRAM of certain values do not survive reboot. One work around is to run the latest Asus-Merlin firmware 386.11 on the RT-AC68U including running the clear_vpnclients.sh script indicated in the 386.11 firmware Change Log. The 386.11 firmware has the number of OpenVPN clients reduced from five to two in an effort to deal with the limited NVRAM on the RT-AC68U.
 
In a bit of a random subject, I noticed that the TP-Link Deco AXE 5300 Tri-Band Mesh Router is available for a decent price. Would it be worth considering this setup over my three AC68U's setup? I realize this is a different router that is not part of the ASUS or Merlin ecosystem, but in terms of performance and hardware, does upgrading to this system make sense?
 
In a bit of a random subject, I noticed that the TP-Link Deco AXE 5300 Tri-Band Mesh Router is available for a decent price. Would it be worth considering this setup over my three AC68U's setup? I realize this is a different router that is not part of the ASUS or Merlin ecosystem, but in terms of performance and hardware, does upgrading to this system make sense?

TP Link generally makes good stuff but usually the stuff "inside" is going to be cheaper compared to a comparable Asus, hence the cheaper price. There is no way to predict exactly how it will work in your space vs. an Asus but if you're looking to squeeze the best coverage and performance out of a single router, the Asus may be superior (or may be about the same). Assuming where you buy it from has a good return policy, you can try it out and see.
 
I've been using two routers in main/AP mode for many years now at two locations. The setup is 100% trouble-free in both locations, and everything just works. And I don't think you'll see anyone posting in this forum about issues with using AP mode. The only downside, and its a very minor downside, is that when an updated firmware is available, both routers have to be individually updated. And I suppose its fair to say that AP mode takes a little extra effort to optimally set up. And of course a big requirement is that ethernet can be run to the APs.

AI Mesh is attractive in the regard that the main router handles everything and system essentially configures itself. And it doesn't require ethernet between the main router and the nodes (although my impression is that many people do use ethernet). However, I've been watching the evolution of AI Mesh since it was in beta, and even in its current, mature state (if its fair to say that), there are always some people who are having some kind of issue or another with it. I realize that the people with issues are going to be more obvious than the people without issues, but the fact that there are people with issues is a big difference compared to AP mode.

So my recommendation will always be for AP mode for anyone who has the ability and willingness to spend a little time configuring the APs and can run ethernet to the APs.

Do not worry about the RAM usage creeping up to 95% or higher. It is normal and will not cause any problems. This has been discussed many times in this forum.

However, the NVRAM issue needs to be addressed, or it will cause instability issues. A hard reset needs to be done to any of your AC68Us with this issue. Merlin 386.11 needs to be installed before doing the reset. I would do a hard reset just to make sure the routers are in an optimal starting state. There's nothing else that needs to be done or can be done. I expect that your AC68Us in AP mode will never have an NVRAM issue after a hard reset, but I suspect there is a chance that your main router may eventually exhibit NVRAM issues again. It will depend on how much custom configuration is performed to the router and what features you enable. And I suspect that the NVRAM issue will have a higher probability of occurring with all the routers if you use AI Mesh mode.
 
I've been using two routers in main/AP mode for many years now at two locations. The setup is 100% trouble-free in both locations, and everything just works. And I don't think you'll see anyone posting in this forum about issues with using AP mode. The only downside, and its a very minor downside, is that when an updated firmware is available, both routers have to be individually updated. And I suppose its fair to say that AP mode takes a little extra effort to optimally set up. And of course a big requirement is that ethernet can be run to the APs.

AI Mesh is attractive in the regard that the main router handles everything and system essentially configures itself. And it doesn't require ethernet between the main router and the nodes (although my impression is that many people do use ethernet). However, I've been watching the evolution of AI Mesh since it was in beta, and even in its current, mature state (if its fair to say that), there are always some people who are having some kind of issue or another with it. I realize that the people with issues are going to be more obvious than the people without issues, but the fact that there are people with issues is a big difference compared to AP mode.

So my recommendation will always be for AP mode for anyone who has the ability and willingness to spend a little time configuring the APs and can run ethernet to the APs.

Do not worry about the RAM usage creeping up to 95% or higher. It is normal and will not cause any problems. This has been discussed many times in this forum.

However, the NVRAM issue needs to be addressed, or it will cause instability issues. A hard reset needs to be done to any of your AC68Us with this issue. Merlin 386.11 needs to be installed before doing the reset. I would do a hard reset just to make sure the routers are in an optimal starting state. There's nothing else that needs to be done or can be done. I expect that your AC68Us in AP mode will never have an NVRAM issue after a hard reset, but I suspect there is a chance that your main router may eventually exhibit NVRAM issues again. It will depend on how much custom configuration is performed to the router and what features you enable. And I suspect that the NVRAM issue will have a higher probability of occurring with all the routers if you use AI Mesh mode.

The main downside (more than firmware) is you can't have an isolated guest network in AP mode without Aimesh or somewhat complex scripting.

Some people find the roaming of the Aimesh system works well, others hate it, so I guess that one is a YMMV.

If isolated guest isn't a need, having two separate devices is more flexible and also allows you to have separate channels on both where Aimesh forces the same one. In theory the same one makes roaming a tiny bit quicker but the disadvantage is obvious.

I guess on the flip side "more flexible" means more complex for some, and they may prefer the single interface and letting AiMesh do it's thing.

I think the answer is probably try both and see what works for you, or which you like better.
 
The main downside (more than firmware) is you can't have an isolated guest network in AP mode without Aimesh or somewhat complex scripting.

Good point. I had forgotten about this because the script is pretty easy to implement and works well.
 
Just following up here... today I had a weird experience where all my devices stopped having internet connectivity but was able to access devices on my LAN without an issue. I was unable to access the router GUI as well. However, with a reboot, everything started functioning again. My suspicion is the RAM got full as when I checked the metrics earlier this week it was sitting at ~177MB used out of the total 256MB. I don't have any sort of plugin or 3rd party services enabled on the router and am still using it in AIMesh with my other two nodes (both RT-AC68U's).

Honestly, I have no issues with this setup as given my internet speeds, and devices I don't feel any reason to upgrade. However, the RAM usage is a bit concerning as it generally grows over time. Is there a proper way to clear the RAM and automate this process? Or maybe is scheduled reboots every couple of weeks a better option? Or are there other options worth exploring? Or can this issue maybe be tied to something else outside of the RAM?
 
Just following up here... today I had a weird experience where all my devices stopped having internet connectivity but was able to access devices on my LAN without an issue. I was unable to access the router GUI as well. However, with a reboot, everything started functioning again. My suspicion is the RAM got full as when I checked the metrics earlier this week it was sitting at ~177MB used out of the total 256MB. I don't have any sort of plugin or 3rd party services enabled on the router and am still using it in AIMesh with my other two nodes (both RT-AC68U's).

Honestly, I have no issues with this setup as given my internet speeds, and devices I don't feel any reason to upgrade. However, the RAM usage is a bit concerning as it generally grows over time. Is there a proper way to clear the RAM and automate this process? Or maybe is scheduled reboots every couple of weeks a better option? Or are there other options worth exploring? Or can this issue maybe be tied to something else outside of the RAM?

The underlying Linux OS already handles RAM appropriately. Its not uncommon for the RAM allocation to be near the max available space. The OS will clear space as needed.
 
I have three RT-AC68U's that serve my internet needs perfectly fine for the last few years, and I believe they should continue to do my internet needs fine for the foreseeable future. However, I am exploring two options for these three routers:
  1. Option # 1: One RT-AC68U setup as the primary router, other two RT-AC68U's setup in AP mode with WiFi SSID's having the same name and password but setup on different channels to promote better roaming.
  2. Option # 2: Setup one RT-AC68U as the primary router, and the other two RT-AC68U setup as AiMesh nodes, having AiMesh handle all the setup (no configuration of SSID channels, etc...).
I have tried both options and I don't see any performance issues, however, when I do use my entire router in AIMesh, I have noticed the RAM on the primary router slowly creeps up within a few days, whereas within a week or two, the RAM is near ~95% usage. This prompts a reboot to stabilize everything. I never noticed this issue when using Option # 1. I am also using the latest version of the Merlin firmware (368.11). I also see a pop-up of NVRAM usage being high, however, I am not sure if this is seen as a concern.

Therefore, I was wondering if there is any benefit to using AiMesh with the RT-AC68U? Is it more taxing on the hardware since this is older hardware to have it in this setup, and instead using the other two routers in AP mode easier than the primary router? Also, from a performance level, does setting up via AP Mode versus AiMesh provide better performance in general? I can't see any differences from regular speed tests, but not sure if having my SSIDs on different channels is beneficial for my setup.
That's a good plan. You don't have to use AX devices if you don't need them. There are too many people who are using AX routers without any AX devices. 802.11AC is enough for most home users.
 
I never used the reboot schedulre in all the years I have had these routers. Does anyone use this functionality? I am wondering if I should use this as my band-aid solution.
 
I never used the reboot schedulre in all the years I have had these routers. Does anyone use this functionality? I am wondering if I should use this as my band-aid solution.

Many people use reboot scheduler for similar quirks, but it may just be time for a full factory reset and reconfigure of all the routers. After upgrading to 386.11 you have to clear out various NVRAM variables for the 68U to handle it properly. There is a script included you can run but I took advantage of it as a chance to just clean everything out. This isn't the same script you find in the forums, it is one Merlin included with the firmware to remove several VPNs which permanently clears up NVRAM space. Doing a factory reset also permanently removes the variables.

Mine runs under 100M RAM even after weeks of uptime. I'm not running AIMesh though.

In reality you may just want to run the latest stock on the nodes and Merlin on the main router only, generally that is the recommendation.

EDIT apologies, I misspoke, mine never falls below 100M free is what I should have said (so around 150 in use).
 
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Many people use reboot scheduler for similar quirks, but it may just be time for a full factory reset and reconfigure of all the routers. After upgrading to 386.11 you have to clear out various NVRAM variables for the 68U to handle it properly. There is a script included you can run but I took advantage of it as a chance to just clean everything out. This isn't the same script you find in the forums, it is one Merlin included with the firmware to remove several VPNs which permanently clears up NVRAM space. Doing a factory reset also permanently removes the variables.

Mine runs under 100M RAM even after weeks of uptime. I'm not running AIMesh though.

In reality you may just want to run the latest stock on the nodes and Merlin on the main router only, generally that is the recommendation.

EDIT apologies, I misspoke, mine never falls below 100M free is what I should have said (so around 150 in use).

I appreciate the advice! I am also wondering if I should revert back to having the two AiMesh nodes run as separate APs... I suppose reboot schedular isn't a terrible option either since AiMesh does provide the convenience of everything being managed through the primary router.

I also have run the script in Merlin to free up VPNs, which helped reduce my NVRAM to 62907 / 65536 bytes (though still nagging me about low NVRAM, much better than before nonetheless). However, I will look into resetting the router, but is there a way to do this and import the basic things such as WiFi configurations, DHCP server configurations, and so forth? Or would I have to redo every configuration?
 
I appreciate the advice! I am also wondering if I should revert back to having the two AiMesh nodes run as separate APs... I suppose reboot schedular isn't a terrible option either since AiMesh does provide the convenience of everything being managed through the primary router.

I also have run the script in Merlin to free up VPNs, which helped reduce my NVRAM to 62907 / 65536 bytes (though still nagging me about low NVRAM, much better than before nonetheless). However, I will look into resetting the router, but is there a way to do this and import the basic things such as WiFi configurations, DHCP server configurations, and so forth? Or would I have to redo every configuration?

You'd need to redo from scratch or it defeats the purpose. If you have a lot of DHCP reservations or custom client list names you can probably export and import those from the CLI but I'd just screen shot and/or copy/paste. You want to start totally clean.

The nodes just factory reset and rejoin. Factory reset them before the master, shut them off, then once master is back up and running, turn them on and rejoin them.

I'd say run stock firmware on the nodes, the latest available. If not already then update those before doing anything else so when you factory reset and eventually rejoin they are ready to go.

You should not need to reboot every 2 days, if you do, something is wrong.
 
Hi all, not looking to revive this thread, but I came across this 3-Pack ASUS ZenWiFi AX1800 XD4... out of curiosity, is anyone familiar with how good this setup is if doing an ethernet-plugged mesh system? Would it be better to have one of these units serve as my primary router over the RT-AC68U? There is obviously no Merlin support, but I assume the stock ASUS firmware is just as good?

I haven't had any issues since setting up the scheduled rebooter, but based on the recommendation of upgrading to newer hardware, I wasn't sure if this could be considered a worthy upgrade.
 

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