RT-AC66U B1 dropping internet

[PlayaSucia]

I'm getting issues with a new RT-AC66U B1 dropping internet. It isn't disconnecting from the router just the internet connection is dropped, then after about 10 seconds give or take it comes back on.
I did go though the 'Troubleshooting wifi issues' sticky at the top of this forum and I have updated the firmware (the one dated 9/19/18), did a factory reset, deleted profiles on the client, ect..

I'm using the basic default settings aside from passwords, SSID and ...
-changed 2.4ghz channel from auto to 11, (an unused channel according to inssider)
-changed 2.4ghz from 20/40 to 20
-changed 5ghz channel from auto to 48 (I tried higher band too but no difference)
-set IPV6 to native (I use comcast and online IPV6 tests check out)
-turned off UPnP
-there is nothing enabled (no AIprotect, AIcloud, QoS, external drives)

When I'm streaming or whatever the status shows the memory usage under 30%, the cpu typically around 5% with small spikes up from time to time. Nothing out of the ordinary.

Background – I had been using a older Netgear WNDR3700v2 (N600) router for around the last six months and it worked fine until the 2.4 radio burned out. Since I have several 2.4 clients I replaced it with this RT-AC66U B1 in part because it seems to be one of the more popular models around here in the sub $100 range.
Overall get better signal around the house with the RT-AC66U B1 but the speeds slightly lower than the N600. I'm pretty realistic about wifi speeds and didn't expect a big change despite going from a 600 to 1750 router, however I did expect it to be relatively the same or slightly better.

I'm going to give it a week but if it keep dropping I'll have to return it and try something else. Is this uncommon? Are there any setting I should look at?
Thanks.

 

[OzarkEdge]

I'm getting issues with a new RT-AC66U B1 dropping internet. It isn't disconnecting from the router just the internet connection is dropped, then after about 10 seconds give or take it comes back on.
I did go though the 'Troubleshooting wifi issues' sticky at the top of this forum and I have updated the firmware (the one dated 9/19/18), did a factory reset, deleted profiles on the client, ect..

I'm using the basic default settings aside from passwords, SSID and ...
-changed 2.4ghz channel from auto to 11, (an unused channel according to inssider)
-changed 2.4ghz from 20/40 to 20
-changed 5ghz channel from auto to 48 (I tried higher band too but no difference)
-set IPV6 to native (I use comcast and online IPV6 tests check out)
-turned off UPnP
-there is nothing enabled (no AIprotect, AIcloud, QoS, external drives)

When I'm streaming or whatever the status shows the memory usage under 30%, the cpu typically around 5% with small spikes up from time to time. Nothing out of the ordinary.

Background – I had been using a older Netgear WNDR3700v2 (N600) router for around the last six months and it worked fine until the 2.4 radio burned out. Since I have several 2.4 clients I replaced it with this RT-AC66U B1 in part because it seems to be one of the more popular models around here in the sub $100 range.
Overall get better signal around the house with the RT-AC66U B1 but the speeds slightly lower than the N600. I'm pretty realistic about wifi speeds and didn't expect a big change despite going from a 600 to 1750 router, however I did expect it to be relatively the same or slightly better.

I'm going to give it a week but if it keep dropping I'll have to return it and try something else. Is this uncommon? Are there any setting I should look at?
Thanks.

Have you tried with IPv6 disabled?

OE

 

[ApexRon]

I'm getting issues with a new RT-AC66U B1 dropping internet. It isn't disconnecting from the router just the internet connection is dropped, then after about 10 seconds give or take it comes back on.
I did go though the 'Troubleshooting wifi issues' sticky at the top of this forum and I have updated the firmware (the one dated 9/19/18), did a factory reset, deleted profiles on the client, ect..

I'm using the basic default settings aside from passwords, SSID and ...
-changed 2.4ghz channel from auto to 11, (an unused channel according to inssider)
-changed 2.4ghz from 20/40 to 20
-changed 5ghz channel from auto to 48 (I tried higher band too but no difference)
-set IPV6 to native (I use comcast and online IPV6 tests check out)
-turned off UPnP
-there is nothing enabled (no AIprotect, AIcloud, QoS, external drives)

When I'm streaming or whatever the status shows the memory usage under 30%, the cpu typically around 5% with small spikes up from time to time. Nothing out of the ordinary.

Background – I had been using a older Netgear WNDR3700v2 (N600) router for around the last six months and it worked fine until the 2.4 radio burned out. Since I have several 2.4 clients I replaced it with this RT-AC66U B1 in part because it seems to be one of the more popular models around here in the sub $100 range.
Overall get better signal around the house with the RT-AC66U B1 but the speeds slightly lower than the N600. I'm pretty realistic about wifi speeds and didn't expect a big change despite going from a 600 to 1750 router, however I did expect it to be relatively the same or slightly better.

I'm going to give it a week but if it keep dropping I'll have to return it and try something else. Is this uncommon? Are there any setting I should look at?
Thanks.

Let me make sure I understand; NO device is losing connection to the AC66U itself, merely the internet. Since you just purchased, I would not install/use anything but ASUS firmware as anything else could jeopardize your warranty as well as your ability to return product.

You did not specify the device used for the internet connection; i.e. modem. Please do.

Have you installed another Ethernet cable between AC66U and 'modem'? If not, please do so. Doesn't matter that the cable worked for the Netgear.

Another possibility is the speed of the connection between AC66U and the 'modem'. Please confirm on router that it is 1G, nothing less.

Do not use the DNS from your ISP. Configure the router to use Google and OpenDNS only.

 

[Pierino]

Rmerlin firmware doesn’t void the warranty. Feel free to try it out.

 

[PlayaSucia]

Thanks for the responses everyone...

Have you tried with IPv6 disabled?

OE

I really didn't test it with IPV6. I'll give it a shot and report back. My IPV6 settings are..

Type = Native
DHCP-PD = enabled
Auto Config = Stateless
Connect to DNS Server automatically = Enable
Enable Router Advertisement = Enable

My solution is flash the firmware Asuswrt-Merlin v384.4_2 (you can try v384.5 if you want, I do not know if this version also has that problem):
https://sourceforge.net/projects/asuswrt-merlin/files/RT-AC68U/Release/

The same problem this person has that you and I:
https://www.snbforums.com/threads/asus-rt-ac3100-losing-connection-super-frusterating.49221/


My old post:

If that worked then that means there is an issue with the current firmware. Would reverting to an earlier solve my issue?
I haven't tried Merlin yet. I want to try it but I have to read more about it - like if I can easily revert to the stock firmware in case I have to send it back.

Let me make sure I understand; NO device is losing connection to the AC66U itself, merely the internet. Since you just purchased, I would not install/use anything but ASUS firmware as anything else could jeopardize your warranty as well as your ability to return product.

You did not specify the device used for the internet connection; i.e. modem. Please do.

Have you installed another Ethernet cable between AC66U and 'modem'? If not, please do so. Doesn't matter that the cable worked for the Netgear.

Another possibility is the speed of the connection between AC66U and the 'modem'. Please confirm on router that it is 1G, nothing less.

Do not use the DNS from your ISP. Configure the router to use Google and OpenDNS only.

Correct. It doesn't randomly drop, rather it drops when connecting -- for example while internet browsing things will work fine for some time then suddenly a page or link will time out, my internet status icon gets a yellow triangle exclamation point (Windows 7). It shows I'm still connected to the router but have no internet connection. Then about 10 second or so it will come back.

I'm using a Motorola cable modem (Model MB7420). I have a computer hard wired and it doesn't appear to have the same dropping issue. My internet speed is the same when wired directly at the modem and when wired thru the router (298 Mbps download and 12.10 Mbps upload using ookla for speed tests). Also I have an ooma connected and haven't noticed any performance issues with it. I can swap out the cable but I think it is just the wifi. And as I mentioned my overall wifi speeds are slightly lower than with the N600.

Under WAN I have 'Connect to DNS Server automatically = Yes'
Is that what I should change to OpenDNS?

 

[Grisu]

I haven't tried Merlin yet. I want to try it but I have to read more about it - like if I can easily revert to the stock firmware in case I have to send it back.

you can go back and forth as you like, see Merlin as stock with some features but without Aimesh.
Do a factory reset if you get any uncertain problems after a change, sometimes even helpful on same firmware after greater changes.

 

[ApexRon]

Under WAN I have 'Connect to DNS Server automatically = Yes'
Is that what I should change to OpenDNS?

Correct, change to 'NO' and add DNS for Google DNS and OpenDNS. ISP DNS servers can cause issues similar to what you are experiencing.

It doesn't randomly drop, rather it drops when connecting -- for example while internet browsing things will work fine for some time then suddenly a page or link will time out, my internet status icon gets a yellow triangle exclamation point (Windows 7). It shows I'm still connected to the router but have no internet connection. Then about 10 second or so it will come back.

Really sounds like the connection between the cable modem and ASUS is the issue. Monitor the ASUS system log and when this happens advise as to the entries that occur.

I'm using a Motorola cable modem (Model MB7420). I have a computer hard wired and it doesn't appear to have the same dropping issue.

Possible auto-negotiation issue between cable modem and ASUS which can occur periodically. I would try another Ethernet cable as an older cable may work with prior setup but newer technology in ASUS may have issue. Especially if a computer connected to cable modem has no issue.

 

[PlayaSucia]

I think so, I thought that my router was damaged and because I had these problems, so I decided to flash an old version and it worked, all my problems were solved.

I have no problem with these firmware:
- v384.4_2 (24-Mar-2018) -> GPL 384_20379 (I'm using this firmware)
- v384.5 (13-May-2018) -> GPL 384_20648 (I did not test it for long, only one day and then I decided to go for the oldest version, but on that day, it did not give me any problem)

These firmware give me those problems mentioned above:
- v384.6 (25-July-2018) -> GPL 384_21045
- v384.7 (7-Oct-2018) -> GPL 384_21152


For me the culprit is dnsmasq or USB Modem option.

Ok, the firmware I'm using is one dated 19-Sept-18 from asus, I'll give one of those merlin firmwares a shot if nothing resolves the issue. As long as I can revert it back in the off case I have to return the router, though I'd rather try and figure out the issue. I don't use Aimesh or anything.

Correct, change to 'NO' and add DNS for Google DNS and OpenDNS. ISP DNS servers can cause issues similar to what you are experiencing.
Really sounds like the connection between the cable modem and ASUS is the issue. Monitor the ASUS system log and when this happens advise as to the entries that occur.
Possible auto-negotiation issue between cable modem and ASUS which can occur periodically. I would try another Ethernet cable as an older cable may work with prior setup but newer technology in ASUS may have issue. Especially if a computer connected to cable modem has no issue.

I turned off Air Fairness and Beamforming and my speeds have increased a little bit. It has dropped a couple of times since then but seems more stable.
I've just updated the DNS Server and went ahead and swapped out the modem to router cable with another Cat5e I had. I'll report back with log info when (if) it drops again.

Another thing I've noticed is when I look at the Client List in Network Map the clients will sometimes drop off then the list repopulates several times. It doesn't seem to be related to my connectivity issue here but seems kind of odd. Has anyone else notice that?

 

[ApexRon]

Another thing I've noticed is when I look at the Client List in Network Map the clients will sometimes drop off then the list repopulates several times. It doesn't seem to be related to my connectivity issue here but seems kind of odd. Has anyone else notice that?

My AC86U does the same thing. I believe the router is merely refreshing the device list nothing more.

 

[bbunge]

My RT-AC66U_B1 is running just fine on Merlin 384.7. Have also run John's fork, which has built in support for DNS over TLS. You will need to use the RT-AC68U firmware as the router hardware is the same. Yo may need to go back a few versions of the Asus firmware to use Merlin as the newer factory firmware blocks other party firmware.

Sent from my P01M using Tapatalk

 

[Pierino]

My RT-AC66U_B1 is running just fine on Merlin 384.7. Have also run John's fork, which has built in support for DNS over TLS. You will need to use the RT-AC68U firmware as the router hardware is the same. Yo may need to go back a few versions of the Asus firmware to use Merlin as the newer factory firmware blocks other party firmware.

Sent from my P01M using Tapatalk

I don’t think Asus firmware blocks rmerlin firmware. I could be wrong but I think to the router it is the same.

 

[RMerlin]

I don’t think Asus firmware blocks rmerlin firmware. I could be wrong but I think to the router it is the same.

My firmware uses Asus's validation scheme. The only time it can be problematic is when Asus updates the signature version, which means I also need to update it on my end. This is why for instance you can no longer versions that are too old and predate the last signature change.

 

[PlayaSucia]

Just a quick update. The internet connection issue is less prominent since turning Air Fairness and Beamforming off, however it does still occur.

I haven't noticed anything in the log files other than these 'roamast: eth2: add client [mac address] to monitor list'. Some of the entries occur around the drops but not at the exact time, maybe 5-10 minuets before so I don't think its related.

I'm going to try yet another modem-to-router cable see if that changes things. Overall the speed and throughput performance is not much better than the N600 router prior to it breaking.

 

[bbunge]

I've beaten my router a lot upgrading firmware, switching to Merlin then John's fork, back to official Asus and now Merlin 384.7. All without WIFI or WAN failures! I do turn off Airtime Fairness and Roaming Assistant. Also WPS is off. Always do factory reset after switching firmware. Sometimes turn off Nat Acceleration. Add a swap file to a USB stick. Do not use mesh! Do use QOS and Trend Micro protection. Have a 1 TB USB 2.0 drive attached..
I strongly recommend Merlin's firmware 384.7 for the RT-AC68U!

Sent from my P01M using Tapatalk

 

[meangene]

Have you installed another Ethernet cable between AC66U and 'modem'? If not, please do so. Doesn't matter that the cable worked for the Netgear.

Thank you, I had the same disconnection problem and this fixed my issue. I had a flat cat 7 cable and I replaced it with a regular cat 6 cable.

 

[OzarkEdge]

Thank you, I had the same disconnection problem and this fixed my issue. I had a flat cat 7 cable and I replaced it with a regular cat 6 cable.

Was that the flat patch cable ASUS is now shipping with their routers?

OE

 

[meangene]

Was that the flat patch cable ASUS is now shipping with their routers?

OE

no, one I had bought. I thought it would speed up things but it gave me connection problems instead. I haven't had any since replacing cable. Cable modem is Netgear cm1000 DOCSIS 3.1 and router is Asus RT-AC66U running Asuswrt-Merlin 380.70, here are my results this morning.

 

[PlayaSucia]

I've been playing with the settings - by changing one setting, then waiting a day or two and see if anything changes. Now I turned off the Roaming Assistant and my speed jumped 30-35Mbps! Which was about the speed I was expecting. Not sure why I overlooked Roaming Assistant for so long as I only have the one router. It's funny because even with it enabled I was well within the drop range.
Everything seems stable so far but I'll know for sure in a day or two.

I also switched back to auto DNS. I used a program called 'Namebench' and it reported my isp dns as the fastest. Actually Norton was faster but it is being disconnected in a week.

My Asus router came with a round cable, it is black and unmarked but I assume it is 5e. I suppose those flat patch cables attenuate noise more than the round ones, since the wires aren't twisted. I've had a couple but have never used them.

 

[meangene]

no, one I had bought. I thought it would speed up things but it gave me connection problems instead. I haven't had any since replacing cable. Cable modem is Netgear cm1000 DOCSIS 3.1 and router is Asus RT-AC66U running Asuswrt-Merlin 380.70, here are my results this morning.

View attachment 14878

back to square one, still dropping connection.

 

[meangene]

back to square one, still dropping connection.

This is what I am dealing with.