GL-MT6000 mysterious Wifi client to LAN host issue

Hi,

I've got a GL-MT6000 and I'm running OpenWRT 24.10.0 for a while now and I'm battling with an issue with certain Wifi clients connectivity to a LAN host.

I have a NAS connected to an ethernet port. I have 2 TV boxes connected via ethernet. 5 phones, 2 tablets, 1 laptop connected via Wifi. The problematic behavior is associated with only 2 phones and 1 tablet but never impacted other devices.

The problematic behavior is that after a certain period, those 2 phones and 1 tablet suddenly became speed limited at like 10kbps connecting to the NAS on the LAN. It can't be a Wifi problem because they connects to the Internet fine at full speed. If I ping NAS from those devices, I get like 5ms latency. But just the speed is painfully slow.

Only a reboot of the router can solve this issue. An alternative is for the phone to turn on Wifi-privacy, randomized MAC, to get a new IP address under DHCP. Two of the devices only exhibit this behavior when connected to 2.4GHz Wifi but not 5GHz. It's not a signal strength issue because they run Internet at full speed when exhibit this problem.

This is so mysterious and I can't begin to debug it. Any pointers are much appreciated! Thanks!

Hello,

Please let us double confirm this issue.
It is a 2.4GHz wireless device (referring to the special 2 phones and 1 tablet), if they access the wired NAS device in the LAN, they will be very slow after a period of time.

  1. At this time, is the access speed of the NAS in the LAN normal for other devices (including other devices 2.4GHz + 5GHz + LAN wired)?

  2. At this time, the Internet access speed of the 2 phones and 1 tablet is normal, and that, the Internet speed of all wireless devices is normal, right?

  3. Could you tell us about 2.4GHz abnormal wireless device models (2 phones + 1 tablet)?

  4. If the clients (2 phones + 1 tablet) MAC randomization is not enabled manually (no new IP is obtained), and only just reconnect WiFi, will the clients 2.4GHz WiFi speed normal?

  5. For abnormal 2.4GHz devices, will the speed of access other devices in the LAN be normal?
    For example, you can install the server on the PC in the LAN through iperf3/OpenSpeedtest, and test the speed at the abnormal mobile phone/tablet
    (this point can be confirmed if the issue on 2.4GHz WiFi)

  1. Yes, I've got two iPads, a Macbook and a recent model Vivo X100 Pro, a very old Huawei P20 Pro that are fine and never experienced the issue. Also a TCL TV (2021 model) is fine.
  2. Yes
  3. The 3 devices are all a bit old, Xiaomi-mix-3, Oppo Reno. Tablet is an unknown Huawei, 2019 model perhaps. All Chinese devices. Both Xiaomi-mix3 and Oppo Reno exhibit problem on 5GHz Wifi as well.
  4. Yes, for the 2 of the 3 devices that supports MAC randomization, they work fine if this option is used. If I use static DHCP and assign those IPs with non-randomized MAC, it won't work.
  5. UPDATE: I'm able to run OpenSpeedTest and am able to narrow down the problem to Wifi to wired Ethernet clients. The router currently exhibits this problem. But if I run speed test between problematic devices and a Macbook on Wifi, I get 300-400Mbps, close to the maximum. However, if I place OpenSpeedTest on the NAS or another PC server that's connected on the Ethernet port, I get something like the graphs attached. On the download (0.004), it was initially rated at 1Mbps, but quickly diminish to zero. It does that every time. On the upload (0.986), it has this weird graph that the speed would suddenly shot up.

A lot of our old devices are just connected to particular bluetooth speakers so that family members can enjoy some downloaded podcasts or music in different rooms.

For the record, I'm using two pieces of software on openwrt, namely WireGuard and Collectd. WireGuard was set up so that I can access home LAN from cellular network. I copied the setting from an older Linksys device that runs an older version of openwrt. It runs on a separate subnet, 10.0.0.1. Collectd was used to monitor a couple of server ping time and wifi signal strength to quickly diagnose if there's a connection issue.

I also have guest-network like firewall setup, a certain wifi access point was configured to use a 'guest interface' and disallow access to the LAN.

Update bump.

Hello,

Sorry for the late reply.
I tried reproducing on my MT6000 and it seems didn't reproduce.

My topology is relatively simple:
PC --- (LAN) --- MT6000 (with 4.7.0-op24) --- (WLAN-2.4G) ---Huawei Mate70 / iPhone 15 Pro / iPhone 11 Pro / Samsung S6 (old sample), the openspeedtest can exceed 20Mbps.

Please try to reset the firmware of MT6000 and try it again.
It may be that the nearby 2.4GHz WiFi has a large interference and high signal-to-noise, which affects some old model 2.4GHz WiFi wireless performance.

Actually I understand it's probably difficult to reproduce the issue, which is why I asked for pointers to diagnose by myself. But so far I don't understand the mechanics behind.

But one thing is certain, that it's not related to Wifi signal strength. Again, problematic devices had fine Internet access, fine Wifi client access, only problematic wired Ethernet client access.

Yes, it has not been reproduced for the time being.

Oh correctly, it may be that there is an abnormality in the WLAN-LAN link, and it is likely to be related to the wireless client model.

Try testing other firmware more, if possible you can install Vanilla OpenWRT and test it.

Thanks for the help Bruce. Appreciate it.