GL-AX1800 Flint ping jitter problem

I’m using the GL-AX1800 Flint as an access point. I have primary 5GHz + 2.4GHz wireless networks which are bridged to the lan device which includes ethernet ports 0 to 3 (wan, lan1, lan2, lan3). Then I have a second guest network which is only on 2.4GHz and is bridged to ethernet port 4 (lan4). This setup works great. My primary router (Fritz Box) has the option of enabling its guest network on its LAN4 port, so now I have my GL.iNet providing both regular wifi and guest wifi from one device but physically segregated.

I have an intermittent problem. Every 10 seconds or so, my ping time from laptop to router goes from 2ms up to around 100ms. The slow down lasts for only 2-5 seconds. Also, the same slowdowns appear on 2 laptops (one on each wifi network). But the slowdowns happen at different times.

Here’s a screenshot to explain what I mean. This is the prettyping command running on my laptop. It is pinging the access point’s IP, not an internet IP. Sometimes it runs smoothly (see the middle of the picture), and then it enters a period of slowdowns.

My naive thought is that the CPU gets overloaded every so often. But that’s purely a guest.

I had this problem on the 3.214 stable firmware, then I upgraded to the 4.2.0 beta2 firmware. Same problem. I’ve checked the logs, and I don’t see anything happening in any of the logs when these slow downs occur.

Can anyone suggest a next step to try and debug this issue?

Without your specific setup, i.e. use the router in its default settings, do you still have the ping latency problem?

What is the Wireless Encryption security?

Could be the router location, a hardware issue or channel\bandwidth interference. Could also be a “rogue device” on the network that is misbehaving and needs a reset. Sense you ran it on you laptop check your wireless card settings for power saving features and such that may cause the slowdown.

:gl_emoji_dizzy:I do not work for and I am not directly associated with GL.iNet :gl_emoji_shacking:

@alzhao I’m 99% sure that we had this issue before I configured the second wifi network.

@K3rn3l_Ku5h The encryption setting is “WPA2 PSK (CCMP)”. I thought I’d chosen WPA2/3 but I must have forgotten to choose that again after upgrading the firmware.

As we’re still inside the return window, I’ve ordered a second duplicate unit and am sending this one back. Hopefully it’s a hardware issue and the replacement will work fine. I’ve checked the reviews and I don’t see anyone else with this problem, so I’m optimistic it’s an isolated issue.

Also, thanks for this suggestion. I tried looking into it a bit, but the slow downs are so random it seems unlikely that any of our devices were joining / leaving the network at those times. Unless it’s somebody’s phone, but even then, I couldn’t find any pattern of people arriving / leaving related to the issue.

The replacement router has arrived today, I installed it, without any custom configuration. I just set it as an access point, plugged it in, and now I have the same problem again. Every 10s or so, the ping time goes up from <10ms to >200ms. Again it’s intermittent.

I’ve tried watching the connected clients list, but I can’t see any pattern where nodes join or leave the network when this problem occurs.

I’m at a loss. I fear I may need to return the replacement unit and switch to a totally different brand. Which would be unfortunate as I’ve had great experiences with GL.iNet routers in the past, and I generally love the interface and the easy access to the OpenWRT control panel.

I’ve always experienced the same with my flint but I live in high density dwelling with 50SSIDs around me. It’s really difficult to debug where the issue is. I ended getting an ubiquity AP that I use for Wifi and then the Flint for routing/VPNs. Using Ubiquity AP there are no issues on same channel and same client (802.11ac, channel 36, 80Mhz) so I’m assuming there’s something funky about the Wifi setup on flint, either drivers, HW or maybe RF env issues… flint is a bit farther than Ubiquity. I wish Flint supported DFS channels.

Just took a sample with pretty ping for a few mins:

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@glinetlvr Thanks. Great to know that I’m not the only one with this issue.

Is the prettyping screenshot taken from the Ubiquity AP or is it from the GL.iNet Flint?

Does your ubiquity AP also run OpenWRT? I’d be curious to know which one you have and if you’d recommend it! :slight_smile: I’m looking at alternatives and would only be using it as an access point, same situation as yours.

That screenshot is from the flint as AP using an 802.11ac client, but I wouldn’t put that much blame on flint. Was trying an ax client and things look better.

In my personal experience of years dealing with this, getting Wifi right and solid on home equipment is just super hard and that’s why I just get an Ubiquity AP independent of the router. They are super solid and if you have wifi issues you know issues are elsewhere… on the client or RF env. Also you just swap that out if you want to bump up Wifi version. I set up UB AP on 120DFS and with tools I know I’m the only one around in that channel… so it’s as good as it’ll be. I have the U6-LR running in standalone mode. Have no idea what it runs on… just need it as an AP and setup the basics and plugged onto the switch.

Just did another test with ax client on 2x2 MIMO, ax, 80Mhz, ch36, and things look comparable here. Top is Ubiquiti U6-LR, bottom is flint. Flint is a bit further away so more challenging, but still did ok.


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I’ve seen a few recommendations for that Ubiquiti 6 LR, and it’s only a little more expensive. Thanks for the suggestion. :+1:

Edit: Looks like it’s nearly double the cost of the flint. But maybe still worth it…

Please remember U6-LR does not have any routing features. It’s exclusively an AP.

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I have an Unifi U6-Pro access point and it is indeed rock solid, as @glinetlvr stated for the U6-LR.

Be aware that Ubiquiti Unifi products do not have web user interfaces for setup and administration. They have to be controlled through an Unifi Network Application that manages and monitors all the Unifi devices on your network and that should be continuously running. If you are used to consumer routers/access points, then you may have some learning curve to get through.

I do not work for and I do not have formal association with GL.iNet

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@wcs2228 Thanks for the extra info. More and more people suggesting Ubiquiti is a good choice!

The stuff I’m reading suggests that the APs can be controlled with an mobile app. But I didn’t realise that they don’t have a web interface, thanks for pointing that out.

Now I’m getting way off topic, but how have you mounted the U6? Does it need to be ceiling mounted, or is it sufficient to place it facing upwards on a high surface?

Ubiquity APs can be run in “standalone” mode. You manage them through the phone app, and don’t require anything else.

You do lose a lot of the geekiness that the unifi controller software offers. But if you only have one AP and want to set and forget it should be fine.

As per mounting, the round flat APs, have directional radiation pattern. You can check the datasheet but the back of the AP is a nul for propagation. Taking that into consideration you can mount it accordingly. I have it flat on a lower Ikea tv stand and works great. No need for mounting. App software even allows to turn off the LED so looks cool and not obtrusive.

I do not use the Unifi mobile app because Unifi is an entire ecosystem and I like geeky stuff :rofl:. I have since added a UAP-AC-M that creates a seamless wifi mesh to cover a deadspot.

Note that the Unifi U6 models do not include POE injectors, so you have to buy one separately or use a POE switch (which is what I have).

Before settling on Unifi, you may want to look into the TP-Link Omada business access points. I previously had an EAP245 V3 wifi 5/AC model that worked well and they now have an EAP620 HD wifi 6/AX model. These devices can be managed through web user interface, mobile app or Omada controller unit.

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