Solved RT-AC86U Ping spikes on 5GHz Wifi

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kordeiro

New Around Here
I seem to be having exactly the same problem described above. I am using a RT-AC86U router and am the only client on the 5 GHz wifi, the other. clients are on 2.4Ghz.

I get get pretty regular ping spikes on the 5GHz wifi which make playing online games impossible. I know, for sure, that it is not my ISP as plugging in a LAN cable or using the already congested 2.4GHz channel works fine without any issues.

Here is an example of a ping test from my PC to the router IP (5GHz):
ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1): 56 data bytes
Request timeout for icmp_seq 0
64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=1906.274 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=904.388 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=1.259 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=5.524 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=56.250 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=96.461 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=2.258 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=35.103 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=45.953 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=58.963 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=9.100 ms
64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=1.379 ms
64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=8.654 ms
64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=8.946 ms
64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=1.907 ms
64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=1.559 ms
64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=1941.317 ms
64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=940.940 ms
64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=109.900 ms
64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=1.505 ms
64 bytes from 192.168.1.1: icmp_seq=20 ttl=64 time=1.970 ms
64 bytes from 192.168.1.1: icmp_seq=21 ttl=64 time=2.832 ms
64 bytes from 192.168.1.1: icmp_seq=22 ttl=64 time=9.493 ms
64 bytes from 192.168.1.1: icmp_seq=23 ttl=64 time=9.438 ms
64 bytes from 192.168.1.1: icmp_seq=24 ttl=64 time=9.685 ms
64 bytes from 192.168.1.1: icmp_seq=25 ttl=64 time=8.857 ms
64 bytes from 192.168.1.1: icmp_seq=26 ttl=64 time=9.169 ms
64 bytes from 192.168.1.1: icmp_seq=27 ttl=64 time=8.818 ms
64 bytes from 192.168.1.1: icmp_seq=28 ttl=64 time=8.928 ms
64 bytes from 192.168.1.1: icmp_seq=29 ttl=64 time=8.732 ms
64 bytes from 192.168.1.1: icmp_seq=30 ttl=64 time=11.618 ms
64 bytes from 192.168.1.1: icmp_seq=31 ttl=64 time=1.356 ms
64 bytes from 192.168.1.1: icmp_seq=32 ttl=64 time=1979.665 ms
64 bytes from 192.168.1.1: icmp_seq=33 ttl=64 time=976.014 ms
64 bytes from 192.168.1.1: icmp_seq=34 ttl=64 time=1.604 ms
64 bytes from 192.168.1.1: icmp_seq=35 ttl=64 time=2.040 ms
^C
--- 192.168.1.1 ping statistics ---
36 packets transmitted, 36 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 1.259/255.218/1979.665/569.237 ms


As you can see there are ping spikes of nearly 2 seconds! I was able to reproduce this issue on all my PCs, mac, windows and linux so I am pretty certain its not a client or OS specific issue but rather with the router possibly?

Here is exactly the same test from my PC to the router IP (2.4GHz):
ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=9.813 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=10.325 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=93.894 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=133.613 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=4.686 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=58.811 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=2.869 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=44.232 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=62.617 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=75.770 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=2.317 ms
64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=1.650 ms
64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=11.171 ms
64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=8.751 ms
64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=1.488 ms
64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=8.764 ms
64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=1.468 ms
64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=1.278 ms
64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=9.062 ms
64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=8.735 ms
64 bytes from 192.168.1.1: icmp_seq=20 ttl=64 time=1.648 ms
64 bytes from 192.168.1.1: icmp_seq=21 ttl=64 time=1.640 ms
64 bytes from 192.168.1.1: icmp_seq=22 ttl=64 time=8.788 ms
64 bytes from 192.168.1.1: icmp_seq=23 ttl=64 time=3.675 ms
64 bytes from 192.168.1.1: icmp_seq=24 ttl=64 time=1.534 ms
64 bytes from 192.168.1.1: icmp_seq=25 ttl=64 time=8.943 ms
64 bytes from 192.168.1.1: icmp_seq=26 ttl=64 time=3.193 ms
64 bytes from 192.168.1.1: icmp_seq=27 ttl=64 time=121.964 ms
64 bytes from 192.168.1.1: icmp_seq=28 ttl=64 time=1.348 ms
64 bytes from 192.168.1.1: icmp_seq=29 ttl=64 time=48.689 ms
64 bytes from 192.168.1.1: icmp_seq=30 ttl=64 time=5.123 ms
64 bytes from 192.168.1.1: icmp_seq=31 ttl=64 time=8.697 ms
64 bytes from 192.168.1.1: icmp_seq=32 ttl=64 time=1.510 ms
64 bytes from 192.168.1.1: icmp_seq=33 ttl=64 time=8.713 ms
64 bytes from 192.168.1.1: icmp_seq=34 ttl=64 time=10.210 ms
64 bytes from 192.168.1.1: icmp_seq=35 ttl=64 time=1.690 ms
64 bytes from 192.168.1.1: icmp_seq=36 ttl=64 time=1.620 ms
64 bytes from 192.168.1.1: icmp_seq=37 ttl=64 time=8.690 ms
64 bytes from 192.168.1.1: icmp_seq=38 ttl=64 time=1.894 ms
64 bytes from 192.168.1.1: icmp_seq=39 ttl=64 time=1.417 ms
64 bytes from 192.168.1.1: icmp_seq=40 ttl=64 time=35.784 ms
64 bytes from 192.168.1.1: icmp_seq=41 ttl=64 time=122.573 ms
^C
--- 192.168.1.1 ping statistics ---
42 packets transmitted, 42 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 1.278/22.873/133.613/36.045 ms


As you can see its a lot more stable despite all my other devices being on 2.4GHz as well.

I am also 3-4 meters away from my router and have line of sight, there are no walls ect. in the way. I have also used NetSpot to check for interfering channels from neighbours, but I am the only one with 5GHz wifi (screenshot 1). In comparison, the 2.4GHz channels are quite congested but I get better stability during ping tests (screenshot 2).
Screenshot 2020-10-15 at 10.32.01.png

Screenshot 2020-10-15 at 10.32.08.png


One last thing to note is that I used to be able to play games on 5GHz without any issues at all. This started happening quite suddenly (after a firmware upgrade I am suspecting?) There are also only 8 clients in total connected to the router, 4 of which are wired anyway, so I don't think the router is being strained at all either. I have also reset the router to factory settings and the issue persists.

I also have no USB devices connected to the router at all, only wired LAN cables.

If you are experiencing the same thing or are able to help please let me know. It would be greatly appreciated!
 

kordeiro

New Around Here
It's worth mentioning that I have also reset and nuclear reset the router several times and even tried the latest Merlin firmware and the issue persists.
 

kordeiro

New Around Here
Last thing, I also connected a shirtty cheap router directly to the RT-86U and connected to the 5GHz AP of the crap router. Running a ping test to the RT-86U worked fine without any massive ping spikes so I don't think there is any interference where I live that could be causing this...
 

L&LD

Part of the Furniture
After resetting the router, how are you setting it up? Minimally and manually set up the router and start by using the defaults suggested in the M&M Config guide (see link in my signature below) and only change/add your customizations one at a time after fully testing after each change made (I would also recommend rebooting the router and the client devices and then waiting for at least 10 to 15 minutes before testing each change too).
 

kordeiro

New Around Here
Hey,

After resetting the router I just setup the WiFi SSID and password that you have to setup during the welcome wizard. I've then followed the rest of the steps mentioned in the guide to the T.

I also tested channels 36 to 48 as those are the only ones that are available in my country.

I've powered off the device for 30 minutes and disconnected all wireless clients, but the issue mentioned above still persists.

After resetting the router, how are you setting it up? Minimally and manually set up the router and start by using the defaults suggested in the M&M Config guide (see link in my signature below) and only change/add your customizations one at a time after fully testing after each change made (I would also recommend rebooting the router and the client devices and then waiting for at least 10 to 15 minutes before testing each change too).
 

OzarkEdge

Part of the Furniture
FWIW, I'm running Asuswrt RC2-6 AiMesh 2.0 beta 9.0.0.4.386.40322 on a 2xRT-AC86U AiMesh with 5.0 wireless backhaul. Using a 5.0 wireless PC connection to the router/root node, I get these ping results:

Ping statistics for 192.168.1.1 (router/root node direct):
Packets: Sent = 63, Received = 63, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 28ms, Average = 1ms

Ping statistics for 192.168.1.74 (remote node across 5.0 77' backhaul):
Packets: Sent = 62, Received = 62, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 7ms, Average = 2ms

I suspect I'd get similar results with the current Asuswrt 3.0.0.4.384.82072.

OE
 
Last edited:

kordeiro

New Around Here
I would fall back to the firmware that was stable. I've had to do this in the past myself due to instability with the latest firmware and WiFi connectivity. You can find all available firmware to your model here: https://www.asus.com/us/Networking/RT-AC86U/HelpDesk_BIOS/
Hey,

I tried rolling back to firmware from the beginning of this year after trying what L&LD suggested. Still followed the M&M config procedure and the issue is still present. At this point should I be suspecting bad hardware in the 5GHz circuit?
 

kordeiro

New Around Here
Another thing I just noticed is that the ping spike is pretty consistent and regular. It happens every 16 seconds exactly.

64 bytes from 192.168.1.1: icmp_seq=46 ttl=64 time=1011.801 ms
64 bytes from 192.168.1.1: icmp_seq=47 ttl=64 time=10.188 ms
64 bytes from 192.168.1.1: icmp_seq=48 ttl=64 time=9.461 ms
64 bytes from 192.168.1.1: icmp_seq=49 ttl=64 time=8.728 ms
64 bytes from 192.168.1.1: icmp_seq=50 ttl=64 time=9.253 ms
64 bytes from 192.168.1.1: icmp_seq=51 ttl=64 time=9.085 ms
64 bytes from 192.168.1.1: icmp_seq=52 ttl=64 time=8.886 ms
64 bytes from 192.168.1.1: icmp_seq=53 ttl=64 time=8.947 ms
64 bytes from 192.168.1.1: icmp_seq=54 ttl=64 time=8.761 ms
64 bytes from 192.168.1.1: icmp_seq=55 ttl=64 time=4.918 ms
64 bytes from 192.168.1.1: icmp_seq=56 ttl=64 time=9.000 ms
64 bytes from 192.168.1.1: icmp_seq=57 ttl=64 time=8.917 ms
64 bytes from 192.168.1.1: icmp_seq=58 ttl=64 time=2.746 ms
64 bytes from 192.168.1.1: icmp_seq=59 ttl=64 time=9.156 ms
64 bytes from 192.168.1.1: icmp_seq=60 ttl=64 time=8.483 ms
64 bytes from 192.168.1.1: icmp_seq=61 ttl=64 time=8.741 ms
64 bytes from 192.168.1.1: icmp_seq=62 ttl=64 time=1020.679 ms
64 bytes from 192.168.1.1: icmp_seq=63 ttl=64 time=19.381 ms
64 bytes from 192.168.1.1: icmp_seq=64 ttl=64 time=8.861 ms
64 bytes from 192.168.1.1: icmp_seq=65 ttl=64 time=8.827 ms
64 bytes from 192.168.1.1: icmp_seq=66 ttl=64 time=9.512 ms
64 bytes from 192.168.1.1: icmp_seq=67 ttl=64 time=8.864 ms
64 bytes from 192.168.1.1: icmp_seq=68 ttl=64 time=1.770 ms
64 bytes from 192.168.1.1: icmp_seq=69 ttl=64 time=3.676 ms
64 bytes from 192.168.1.1: icmp_seq=70 ttl=64 time=8.683 ms
64 bytes from 192.168.1.1: icmp_seq=71 ttl=64 time=8.749 ms
64 bytes from 192.168.1.1: icmp_seq=72 ttl=64 time=9.121 ms
64 bytes from 192.168.1.1: icmp_seq=73 ttl=64 time=8.834 ms
64 bytes from 192.168.1.1: icmp_seq=74 ttl=64 time=2.131 ms
64 bytes from 192.168.1.1: icmp_seq=75 ttl=64 time=8.807 ms
64 bytes from 192.168.1.1: icmp_seq=76 ttl=64 time=1.631 ms
64 bytes from 192.168.1.1: icmp_seq=77 ttl=64 time=8.590 ms
64 bytes from 192.168.1.1: icmp_seq=78 ttl=64 time=1074.723 ms
64 bytes from 192.168.1.1: icmp_seq=79 ttl=64 time=69.628 ms
64 bytes from 192.168.1.1: icmp_seq=80 ttl=64 time=1.342 ms
64 bytes from 192.168.1.1: icmp_seq=81 ttl=64 time=9.188 ms
64 bytes from 192.168.1.1: icmp_seq=82 ttl=64 time=8.905 ms
64 bytes from 192.168.1.1: icmp_seq=83 ttl=64 time=7.738 ms
64 bytes from 192.168.1.1: icmp_seq=84 ttl=64 time=8.897 ms
64 bytes from 192.168.1.1: icmp_seq=85 ttl=64 time=8.805 ms
64 bytes from 192.168.1.1: icmp_seq=86 ttl=64 time=9.027 ms
64 bytes from 192.168.1.1: icmp_seq=87 ttl=64 time=8.886 ms
64 bytes from 192.168.1.1: icmp_seq=88 ttl=64 time=1.649 ms
64 bytes from 192.168.1.1: icmp_seq=89 ttl=64 time=9.415 ms
64 bytes from 192.168.1.1: icmp_seq=90 ttl=64 time=8.979 ms
64 bytes from 192.168.1.1: icmp_seq=91 ttl=64 time=8.677 ms
64 bytes from 192.168.1.1: icmp_seq=92 ttl=64 time=8.946 ms
64 bytes from 192.168.1.1: icmp_seq=93 ttl=64 time=8.839 ms
64 bytes from 192.168.1.1: icmp_seq=94 ttl=64 time=1101.139 ms
64 bytes from 192.168.1.1: icmp_seq=95 ttl=64 time=100.151 ms
64 bytes from 192.168.1.1: icmp_seq=96 ttl=64 time=8.749 ms
64 bytes from 192.168.1.1: icmp_seq=97 ttl=64 time=3.640 ms
64 bytes from 192.168.1.1: icmp_seq=98 ttl=64 time=1.512 ms
64 bytes from 192.168.1.1: icmp_seq=99 ttl=64 time=8.657 ms
64 bytes from 192.168.1.1: icmp_seq=100 ttl=64 time=8.748 ms
64 bytes from 192.168.1.1: icmp_seq=101 ttl=64 time=8.680 ms
64 bytes from 192.168.1.1: icmp_seq=102 ttl=64 time=9.432 ms
64 bytes from 192.168.1.1: icmp_seq=103 ttl=64 time=9.214 ms
64 bytes from 192.168.1.1: icmp_seq=104 ttl=64 time=8.675 ms
64 bytes from 192.168.1.1: icmp_seq=105 ttl=64 time=1.727 ms
64 bytes from 192.168.1.1: icmp_seq=106 ttl=64 time=8.738 ms
64 bytes from 192.168.1.1: icmp_seq=107 ttl=64 time=8.909 ms
64 bytes from 192.168.1.1: icmp_seq=108 ttl=64 time=1.637 ms
64 bytes from 192.168.1.1: icmp_seq=109 ttl=64 time=8.967 ms
64 bytes from 192.168.1.1: icmp_seq=110 ttl=64 time=1208.384 ms
 

kordeiro

New Around Here
I have figured it out.

My router is pretty close to a wall and other things on a table. If I move the router, literally 5cm forward from the wall, all the ping spikes disappear completely. I have reproduced this now over 8 times. I cannot believe how a few cm makes such a difference but I am assuming it has to do with possible wifi reflections bouncing off something that causes the spikes.

Sorry for wasting anyone's time and thanks for the help.

So happy this is not a hardware fault.
 

OzarkEdge

Part of the Furniture
I have figured it out.

My router is pretty close to a wall and other things on a table. If I move the router, literally 5cm forward from the wall, all the ping spikes disappear completely. I have reproduced this now over 8 times. I cannot believe how a few cm makes such a difference but I am assuming it has to do with possible wifi reflections bouncing off something that causes the spikes.

Sorry for wasting anyone's time and thanks for the help.

So happy this is not a hardware fault.

WiFi can be hard! I hope that was it.

OE
 

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