Router AC-86U keeps dropping internet connection

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D-Smoke

New Around Here
Hi all!
I have a problem that is driving me nuts! My RT AC-86U keeps dropping the internet connection. I've connected another router (not ASUS brand) to see if it's a problem with my internet provider but no issues there - so to me it's something with the router.

I've updated to the latest Firmware (3.0.0.4.386_41634) and also done a factory reset but still the same problem.

Attached is a short system log from this morning when it went down at about 07:00.

Any help is appreciated!
 

Attachments

  • Asus RT-AC86U LOG2.txt
    4.4 KB · Views: 48

Jeffrey Young

Senior Member
From the logs, you are getting the "ISP not functioning properly" error. This one does drive folks nuts.

I don't use stock firmware, but I believe ASUS has an option in the WAN setup page called "DHCP Query Frequency". Set this to "Continuous mode". This has resolved this error for a lot of folks.
 

D-Smoke

New Around Here
Thanks for the tip! I'll try that and see if it works. Fingers crossed!
BTW, someone suggested me to change to the Merlin FW. Do you think that could solve it too?
 

Jeffrey Young

Senior Member
If the current stock firmware does not have the "Continuous mode" option, then yes going with Merlin would be an option as I have it on my AC86U.

I'm not really sure if Merlin has done any changes to the WAN code, or if he can (many parts of the ASUS code are closed source, so Merlin can't do anything with them anyway).

My take is - if what you got works - don't mess with it. Check out Merlin's notes on his Wiki and see if there are scripts / things that Merlin can do but the stock can't. If you see something that might benefit you, then go for it.


 

D-Smoke

New Around Here
After testing to set DHCP Query Frequency to "Continuous mode, it seems the problem still persists. The internet connection is still lost occasionally :(

I've attached a log from when it happened most recently (so far 2nd time today).

Any other ides? Perhaps try the Merlin FW?
 

Attachments

  • Asus RT-AC86U LOG3.txt
    7.1 KB · Views: 33

Jeffrey Young

Senior Member

D-Smoke

New Around Here
Hi!
The QoS was disabled so that doesn't seem to be the issue.

Yesterday I installed Merlin FW (384.19) and at first it seemed to work flawless. However this morning it was really weird. In the admin interface the internet status stated "Connected", but in fact it seemed disconnected. At least I couldn't open any web page at all. Previously in the stock FW it at least said "Disconnected".

So still looking for answers here guys. Could it be a HW issue? I've been thinking since the router is relatively new it shouldn't be, but who knows...

Any help is appreciated!
 

OzarkEdge

Part of the Furniture
Hi!
The QoS was disabled so that doesn't seem to be the issue.

Yesterday I installed Merlin FW (384.19) and at first it seemed to work flawless. However this morning it was really weird. In the admin interface the internet status stated "Connected", but in fact it seemed disconnected. At least I couldn't open any web page at all. Previously in the stock FW it at least said "Disconnected".

So still looking for answers here guys. Could it be a HW issue? I've been thinking since the router is relatively new it shouldn't be, but who knows...

Any help is appreciated!

Generally speaking, it should work with any firmware.

It could be a hardware issue. Before my AC86U died, I endured a few weeks of a random browser issue not able to resolve URLs. Then it died.

You could try a different WAN cable... maybe the cat bit into it.

If the router was working and now is not working, you might 'feel' its a hardware issue and set it aside.

OE
 

cplay

Senior Member
Generally speaking, it should work with any firmware.

It could be a hardware issue. Before my AC86U died, I endured a few weeks of a random browser issue not able to resolve URLs. Then it died.

You could try a different WAN cable... maybe the cat bit into it.

If the router was working and now is not working, you might 'feel' its a hardware issue and set it aside.

OE
It's not a hardware issue.

The continuous mode does not fix the ISP did not function issue for most people which is why people still complain.


It's horrendous that a router still being sold in 2021 can't perform basic router functions like receiving a new IP address from the ISP router correctly.

If you have an Asus router and an ISP connection with a dynamic IP that renews every day (or sometimes multiple times a day) you are obviously more statistically probable to run into this annoying issue.
 

OzarkEdge

Part of the Furniture
It's not a hardware issue.

The continuous mode does not fix the ISP did not function issue for most people which is why people still complain.


It's horrendous that a router still being sold in 2021 can't perform basic router functions like receiving a new IP address from the ISP router correctly.

If you have an Asus router and an ISP connection with a dynamic IP that renews every day (or sometimes multiple times a day) you are obviously more statistically probable to run into this annoying issue.

My router works fine. You should address your advice to the OP.

OE
 

cplay

Senior Member

OzarkEdge

Part of the Furniture
I was addressing my post to you directly because while your advice was well intentioned, it was incorrect.

https://www.snbforums.com/threads/a...or-isps-dhcp-did-not-function-properly.61907/

unfortunately, the issue is still not fixed with continuous mode enabled and this is most likely the users issue.

all the best,
Cplay

My post was clearly troubleshooting ideas/suggestions, not a declared solution. You're wasting your time 'correcting' such posts here. If you have a solution, direct it to the OP who needs it and we'll all learn from you.

OE
 

djs5916

New Around Here
Just a guess but looking at your LOG3.txt file I would think the following lines are relevant:

Jan 15 12:17:44 kernel: eth0 (Int switch port: 3) (Logical Port: 3) Link DOWN.
..
Jan 15 12:17:45 WAN Connection: ISP's DHCP did not function properly.
..
Jan 15 12:17:47 kernel: eth0 (Int switch port: 3) (Logical Port: 3) Link UP 1000 mbps full duplex
Jan 15 12:17:50 WAN Connection: WAN(0) link up.

It looks like the firmware has reported appropriately that eth0 (WAN port connected to the internal switch port 3) is DOWN.
Then a few seconds later it is found again and connection re-established.

Intermittent connection problems can be a struggle but you must be methodical in debugging them. I generally work from solutions that are quick and easy to check to the more demanding ones if necessary.
So I hope you (and others) can bear the pain of the obvious. I don't think you can easily dismiss hardware issues as they don't always show up immediately, nor can you dismiss software at this point.
- The usual tech support advice: Turn off your ISP's modem/router and your own router. Unplug and reconnect all cables (with appropriate delays for capacitors to discharge) for the WAN connection - fibre/coax/twisted-pair through to the ethernet cabling to your own router. Re-power ISP and check status lights for connection, then re-power your own router and check status lights;
- WAN connection (to ISP router/modem device) cable connection: you can replace/test the cable and RJ45 sockets on both ends; Once I even had a powerbrick's power cable running almost perpendicular to an ethernet cable which showed intermittent disconnections until I moved the power cable - this should be a relatively rare event with modern cables however;
- Internal heat within the router causing problems with some board components: You can almost never rule this possibility out, although you can certainly reduce the software load on the router (by temporarily shutting down optional services), make sure there is optimum airflow around it (it's not right next to a heater?!), cooling vents are unobstructed, etc.. Internal diagnostic/performance indicators should help determine if this is a problem. An IR thermal camera might find a "hotspot" inside your router's electronics. Sometimes an external fan can be used in an attempt to increase airflow/cooling across the router.
- ISP Modem/Router logs: I haven't had a great deal of success with ISP device logs over the past 20 years or so - typically they are underwhelming and don't provide much, if any diagnostic information. If you are lucky and have a customer login to the device you might find a reconnect type message corresponding with the date & time of your own routers reconnection. I'm not sure you can rule out the possibility of a disconnection on the ISP's equipment end yet. It's also possible that the ISP updates their own firmware from time to time and sometimes it doesn't always go well with the connected world. This, of course, is much harder to diagnose without ISP equipment logs, but you might have some success with the ISP's higher level tech support, or not!

All the above process will take a little time and should be part of a generic protocol for reconnecting your own LAN and Router to the outside world via the ISP's equipment. There is one final part of the log3 content that I might speculate upon and might only be relevant to your unique problem - the DHCP conversation between Router and ISP which has been flagged in the log. This might be a concern as you cannot determine which side of the conversation might be at fault - you cannot, for example, reload firmware for the ISP device without their tech support intervention. You certainly can re-flash your own firmware as bit-shifting of ROM contents is still a technical possibility. All the Asus routers firmware update protocols should be followed, remembering to save your existing settings and re-set to default after a successful firmware flash before reloading your "old" settings. All routers are built to a price and very few have adequate cooling for the long-haul, especially when lots of services are running all the time in a heated room. There are a few hacks, adding a 5V fan to the case around the web, which others have found necessary. You don't always have to go this far however!

I haven't looked at anything malicious at this point, even though you can't rule it out completely. It's just quite a bit harder to diagnose, especially if the breach is on the ISP's equipment side. Plug-n-Play services, for example, have been regarded as a security hazard for some time now. I'm assuming you're using your router for some media delivery services, which is why your logs are showing it's enabled.

Anyway, I hope this helps anyone out there. It would be nice if your router showed more problems and pointed to other issues as well. My own guess is with the ISP's equipment and/or connection...

Best regards
Dave
 

L&LD

Part of the Furniture
@djs5916 (Dave), great first post. Welcome to the forums. :)
 

D-Smoke

New Around Here
Hi again. First of all thanks for all the support and suggestions.

Here is a short update on what has happened. Whatever I tried (based on the suggestions from above) I couldn't get the router to work. It still kept dropping the internet connection. Finally I returned it to the retailer and they sent me a new one, exactly the same (RT AC-86U).

After installing it (came with FW 3.0.0.4.384_32799 ) it worked perfect for about a week. Great speed and solid connection. However today I had a power outage in my house and directly after that this new router started acting exactly the same way as the previous one. Constantly dropping internet connection. Tried to do a factory reset but that has made no difference.

Of course I can't be certain but it seems that this router must have some cheap components that can't handle power outages or something? I'll be sending this back and most likely switching either model or brand.

But please let me know your thoughts :)
 

OzarkEdge

Part of the Furniture

djs5916

New Around Here
Yep. I'd agree with good UPS protection on communications equipment. Some comms equipment designs are more tolerant of power fluctuations and some localities have larger variances in power delivery systems than others. Most of us just put in power protection equipment on sensitive low voltage electronic equipment almost as a form of insurance, with battery backup if it can be afforded. There are some decent and modestly priced UPS systems that should be used on such an important shared resource, especially those that serve VOIP telephony services as well.

I have a couple of AC-86U's myself and am very happy with their performance and reliability to date, although I do have them powered by UPS devices; I don't attempt to overwhelm their hardware or cooling capabilities unless I'm debugging a problem on the network; I think I prefer the robustness of Merlin firmware releases to date. I'm not sure I can recommend any better home or small business router with a better feature set for the price - every router has compromises and you should probably use a power protection device on whatever you select. Few routers have adequate heat sink/cooling fans included - you either reduce the feature set which doesn't really sell in the budgetary restricted markets (Home and Small Business) or take your own steps to avoid premature hardware failure, as alluded to in my previous post. Manufacturers aren't so keen on making their devices last too long, which might be the excuse for the absence of good thermal and electrical management solutions in their designs.

Hope this helps and inspires others to add more useful stories.
Regards to all,
Dave
 

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