AC86U x2 and AC66UB1 AI MESH unstable - 3.0.0.4.384_20648

[Ronald Schwerer]

I have tried setting "NAT Acceleration" = "Disabled", however, it does not seem to work for me when I look at Arthur Lien's suggestion, it appears that it is meant only for RT-AC68U.

I believe you need to reboot the router for the NAT acceleration change to take effect. Plus I think you are reading more into Arthur's question than he intended.

I prefer to do Full Factory Reset for a clean restart. I have figured a way that only need a few minutes to Restore specific NVRAM settings and certain items under /jffs that I need by using John's Backup/Restore utilities discussed elsewhere in this forum.

Last time I checked, John's backup script didn't work for the 384 release.

 

[raven-au]

Thanks for the comment to all... I may get another AC86U for 3 node (similar) configuration and see if this is a stable approach.

Am also hoping there is an upcoming firmware from ASUS to have a stable AIMesh scaling.

I started with an AC88U and an AC5300 using AiMesh and added an AC86U a little later.
I've only recently started trying to use AiMesh but thought you might be interested in my experience.

With the AC88U as the main router I had a bunch trouble with a Denon receiver and Sony TV basically failing to connect or disconnecting quickly after connecting.
I changed the main router to be the AC5300 and placed the AC88U where the AC86U was and the AC86U where the AC5300 was and so far this has worked ok but it's only been a couple of days.

What is interesting is that the new location of the AC88U also has a Denon receiver and a Sony TV but they are earlier models and they seem to work ok.

The other interesting thing I encountered is that the AC86U could not be used as the main AiMesh router.

It appeared to me the AC86U is able to use DFS wireless channels (a welcome and long overdue driver enhancement) but the other two routers are not so it would change to 5GHz wireless channels the other two routers could not use causing all sorts of problems like inability to pair or frequent drop outs.

Not using the AC86U as the main router was enough to resolve it.

Another thing I noticed when using more than 2 AiMesh routers is a tendency to chose an indirect path to the main router, via the other of the two, depending on boot order .
That wouldn't be so bad except the choice is not well made and, given the signal at each of the routers, the indirect path will be much slower than choosing to associate with the main router.

Anyway, best of luck!
Ian

 

[LimJK]

Last time I checked, John's backup script didn't work for the 384 release.

Ronald,
Thanks for pointing that out. Yes, from what I know John's backup script does not backup AiMesh specific NVRAM settings yet .
https://www.snbforums.com/threads/user-nvram-save-restore-utility-r26-2.19521/

However, I still run his full backup, as it backups the /jffs directory and subdirectories (I need that to pickup my customized device icons)

If you read the QuickStart.txt, John made a useful utility to allow us to save only selected settings.
In my case I only need to save the followings:
./save-mynvram.sh dhcp_static_x dhcp_staticlist custom_clientlist wan0_upnp_enable vts_enable_x vts_rulelist lan_stp wollist

• Saving dhcp_static_x
• Saving dhcp_staticlist
• Saving custom_clientlist
• Saving wan0_upnp_enable
• Saving vts_enable_x
• Saving vts_rulelist
• Saving lan_stp
• Saving wollist

• Saved 8 NVRAM variable(s)
• Run /tmp/mnt/ASUS/restore-mynvram.sh to restore your saved settings

To restore only selected saved settings (I have validated that these settings does not mess up AiMesh Settings)
./restore-mynvram.sh
nvram commit && reboot

To restore Device icons
cp /tmp/mnt/ASUS/backup/jffs-<2018mmddtttt-0000>/usericon/*.* /jffs/usericon

 

[citrixscu]

Experiencing similar issues with the exact same setup here.
Main AiMesh- AC86U
Node 1 - AC86U
Node 2 - AC66U_B1

Issue here is the router 'forgets' that it is AiMesh after some time. The functionality still works but logging into the router it appears that the UI has reverted to regular router mode. I.e. no mention of AiMesh in the network map page and no mention of Wireless router mode / AiMesh Router mode (Default) in the admin page. Haven't spent much time digging through the logs yet.

 

[jyth_82]

I started with an AC88U and an AC5300 using AiMesh and added an AC86U a little later.
I've only recently started trying to use AiMesh but thought you might be interested in my experience.

With the AC88U as the main router I had a bunch trouble with a Denon receiver and Sony TV basically failing to connect or disconnecting quickly after connecting.
I changed the main router to be the AC5300 and placed the AC88U where the AC86U was and the AC86U where the AC5300 was and so far this has worked ok but it's only been a couple of days.

What is interesting is that the new location of the AC88U also has a Denon receiver and a Sony TV but they are earlier models and they seem to work ok.

The other interesting thing I encountered is that the AC86U could not be used as the main AiMesh router.

It appeared to me the AC86U is able to use DFS wireless channels (a welcome and long overdue driver enhancement) but the other two routers are not so it would change to 5GHz wireless channels the other two routers could not use causing all sorts of problems like inability to pair or frequent drop outs.

Not using the AC86U as the main router was enough to resolve it.

Another thing I noticed when using more than 2 AiMesh routers is a tendency to chose an indirect path to the main router, via the other of the two, depending on boot order .
That wouldn't be so bad except the choice is not well made and, given the signal at each of the routers, the indirect path will be much slower than choosing to associate with the main router.

Anyway, best of luck!
Ian

Interesting note u made that the AC86U can't be used as the main router due to the DFS wireless channel....

Just a different test to see if its HW or software, the test I've conducted to see if the router still crashed/randomly reboots:
1) I've 2 AI mesh node (AC68U and AC86U) and 1 AI mesh main (AC86U). I've swapped the AC86U - same problem
2) I removed the AC68U leaving only 1 AC86U mesh node - main node still crashed
3) I removed the AC86U leaving NO AImesh in the setup - main node still crashed. At this point - I'm thinking that the firmware COULD be the issue.
4) I flashed the AC86U with merlinwrt 384.5.... and it still randomly crashed. Can both the AC86U have HW problems?? Or jut not suitable to be the main mesh node?

Am thinking to get a AC5300 now for test .... but its going to be an expensive test for me. I know AImesh or similar mesh would be the one to go for as the area i need to cover is big. Currently using the intended AImesh nodes as AP mode for now.

Logs for those who wanna figure out what's going on. May 15th is the today's date.

 

[raven-au]

Interesting note u made that the AC86U can't be used as the main router due to the DFS wireless channel....

Just a different test to see if its HW or software, the test I've conducted to see if the router still crashed/randomly reboots:
1) I've 2 AI mesh node (AC68U and AC86U) and 1 AI mesh main (AC86U). I've swapped the AC86U - same problem
2) I removed the AC68U leaving only 1 AC86U mesh node - main node still crashed
3) I removed the AC86U leaving NO AImesh in the setup - main node still crashed. At this point - I'm thinking that the firmware COULD be the issue.
4) I flashed the AC86U with merlinwrt 384.5.... and it still randomly crashed. Can both the AC86U have HW problems?? Or jut not suitable to be the main mesh node?

Am thinking to get a AC5300 now for test .... but its going to be an expensive test for me. I know AImesh or similar mesh would be the one to go for as the area i need to cover is big. Currently using the intended AImesh nodes as AP mode for now.

Logs for those who wanna figure out what's going on. May 15th is the today's date.

Oh, you managed to capture a crash in the log, well done.
That "Feb 14 08:00:18 kernel: Unable to handle kernel paging request" is a kernel crash.
To be sure, once there is a crash in the kernel the router will not function properly, even if it's non-fatal such as a WARN() and doesn't cause a reboot the device is still unlikely to function properly.

There are two possibilities, the first is there are some left over nvram settings causing a problem for the kernel sub-system that's crashing.

When I put my AC5300 back into service to check out AiMesh it was randomly crashing too.
Resting to factory defaults didn't help so eventually I did a WPS reset (although IIRC I did this, along with plain factory reset, a couple of times, no idea why I needed to do it a couple of times) and it has been working fine now for over a week.

It's very puzzling how resetting can make such a difference, and even more puzzling how doing it a couple of times can make a difference at all, but that's my experience.

The second possibility is there really is a problem with something in the firmware kernel (there's not enough information in that log for me to tell which kernel sub-system it is) and the firmware basically doesn't work. If this is the case the only real choice is to try and locate a different firmware release that does work.

Ian

 

[raven-au]

4) I flashed the AC86U with merlinwrt 384.5.... and it still randomly crashed. Can both the AC86U have HW problems?? Or jut not suitable to be the main mesh node?

That is strange.

I guess you could have two routers from a batch that have the same hardware fault, it's possible but I think unlikely.

I purchased an AC86U after running AiMesh with two older devices for a few days and haven't any problems with it (other than it being the only router I have that can handle DFS wireless channels). All I can say is that the AC86U firmware 384_20648-g21e3702 works fine for me.

If you decide to replace one of them to check if it's a hardware fault you would need to be sure the device came from a different batch so you probably can't just go to the place of purchase and request a replacement. Contacting ASUS is I think the best chance for this.

But there is one other possibility that comes to mind.
The crash might be occurring in the wireless driver and you might have some device that has compatibility problems with the driver causing it to crash.
I have seen that, more so recently, and more so with Qualcomm devices than Braodcom devices.

If that's the case there's really not much you can do about it except report it to ASUS but you also need to work out which device (or devices) are problematic and that can be difficult to get right in itself let alone trying to get support staff understand and accept what you trying to say.

All in all a very difficult problem.
I hope my responses are helpful, keep in mind I'm just talking from my own experiences and I could easily be wrong so take that into consideration too.

Ian

 

[raven-au]

Looking again at your log the crash is talking about IPv6.
Do you have IPv6 enabled?

I don't so perhaps there is a bug with the IPv6 support so I don't see it.
Try disabling it if it is enabled to check.

 

[arthurlien]

bbunge,

Thanks for the suggestion, I have tried setting "NAT Acceleration" = "Disabled", however, it does not seem to work for me when I look at Arthur Lien's suggestion, it appears that it is meant only for RT-AC68U.



I prefer to do Full Factory Reset for a clean restart. I have figured a way that only need a few minutes to Restore specific NVRAM settings and certain items under /jffs that I need by using John's Backup/Restore utilities discussed elsewhere in this forum.

typo : if you are using RT-AC68U, RT-AC88U, RT-AC3100 as AiMesh Router (Not Note) and you have wifi call/video drop issue, try to disabled H/W NAT.....

 

[jyth_82]

Looking again at your log the crash is talking about IPv6.
Do you have IPv6 enabled?

I don't so perhaps there is a bug with the IPv6 support so I don't see it.
Try disabling it if it is enabled to check.

IPv6 is disabled...

 

[jyth_82]

That is strange.

I guess you could have two routers from a batch that have the same hardware fault, it's possible but I think unlikely.

I purchased an AC86U after running AiMesh with two older devices for a few days and haven't any problems with it (other than it being the only router I have that can handle DFS wireless channels). All I can say is that the AC86U firmware 384_20648-g21e3702 works fine for me.

If you decide to replace one of them to check if it's a hardware fault you would need to be sure the device came from a different batch so you probably can't just go to the place of purchase and request a replacement. Contacting ASUS is I think the best chance for this.

But there is one other possibility that comes to mind.
The crash might be occurring in the wireless driver and you might have some device that has compatibility problems with the driver causing it to crash.
I have seen that, more so recently, and more so with Qualcomm devices than Braodcom devices.

If that's the case there's really not much you can do about it except report it to ASUS but you also need to work out which device (or devices) are problematic and that can be difficult to get right in itself let alone trying to get support staff understand and accept what you trying to say.

All in all a very difficult problem.
I hope my responses are helpful, keep in mind I'm just talking from my own experiences and I could easily be wrong so take that into consideration too.

Ian

Noted. Will find out if there is any Qualcomm devices. But seems like I'll re-flash it with stock and reset it to completely clear anything within the NVRAM and resetting it again and again ...

If the above still does the same, I'll move down n-1 or n-2 version back to see if its still stable...

Only when all avenue is used up.... I'll use the expensive option...

 

[citrixscu]

Thanks for posting the logs. Watching this thread as I'm experiencing the same issue with the AC86U crashing. I've removed the N66U_B1 from service and am still getting crashes on the 86U. I swapped each and now the main node stays up but the mesh node crashes.

Edit: syslog of offending node attached

 

[bbunge]

Sounds like bad hardware on one AC86U. Put the AC66U_B1 in place of the bad AC86U to see what happens.


Sent from my iPod touch using Tapatalk

 

[citrixscu]

Did a factory restore to see if it helps. Otherwise I guess I'll be going the RMA route.

Edit: Kernel dumps again after recovery firmware restore. Device will be going back to ASUS for repair.

 

[jyth_82]

Hi, Am using n-1 firmware version now : FW_RT_AC86U_300438420467 with default settings after initializing it (twice!!)

So far its been up and running . Will keep everyone updated. RMA route is still there... just not before i do some testing.

 

[raven-au]

Noted. Will find out if there is any Qualcomm devices.

Sorry for the poor description.

I was actually saying I have observed that router devices with Qualcomm wireless have compatibility problems with more devices than those with Broadcom wireless.

Nevertheless the huge range of wireless devices (and the quality of their) drivers that people have on home networks these days appears to be a common problem that shows itself in unexpected and often misleading ways, everything from router crashes to subtle instability.

Very hard to even identify if such a problem is present on the network let alone working out which devices are troublesome.
Not only that it's something that probably needs to be fixed by the wireless (or board) manufacturer which is another lengthy process (I believe).

 

[jyth_82]

HI Folks, bringing up this post with the latest FW from Asus - FW_RT_AC86U_300438421045.

It does crash but not so often. Anyone seeing same problem?

 

[H von Beck]

Not/never had any crashes with AC68U & an AC3100 mesh setup. But had crashes a couple of years ago while using an AC68U as my main router. They run very hot. Try cooling, better heat sinks, etc. Move it or raise and add a fan blowing on it and see what happens. That all helped but I had to replace it. The replacement works fine. So it may be the luck of the draw.

 

[SystemF]

Aimesh note rt-ac66u_b1 latest firm, iptv don't wokring set up port 4 on main router, 1st setup box working on rt-ac88u, second on rt-ac66u_b1 won't start, same settings. shame

 

[Milkman]

FYI, I have a stand-alone AC88u and am having the problem with random reboots.

3.0.0.4.384_32738-gc9a116a