Intermittent connection issues on IoT network

Hi there,

New here, and already loving OpenWRT and the flexibility it's offering on my reasonably priced Archer C7.

I do, however have a couple of issues, which I"m hoping you clever folk can give me some pointers on. The first of these is an intermittent connection dropping of things on my IoT wifi network.

I have an IoT network setup, and can access the devices on this network, however I would frequently lose connection to the Shely smart switches I setup on it (only devices till now), but they would re-appear after a few seconds.

Last night I moved our Chromecasts to the IoT network (with mDNS reflectrion FTW!) and now they are having the same problem (more visually since I can see when it loses it's connection), which also help me understand that it's not an issue with connecting from my lan to the IoT, but an issue with the devices being able to connect to the IoT WiFi.

Can anyone please give me any pointers as to where to start diagnosing this issue? I've looked in the system logs, but can't see anything obvious, but I'm not sure what I'm looking for.

Thanks in advance. T

So I've tred some things to try to fix the Chromecastst this evening (as they're a lot easier to see when they drop offline due to the TV telling me).

I've disabled the "Disassociate On Low Acknowledgement" setting in the WiFi advanced settings, although there was nothing in the system logs about that being why they were being disconnected.

I also installed igmpproxy and enabled IGMP Snooping on both my LAN & IoT bridge interfaces.

Here's all that appear in the log when the disconnect happens…

Mon Sep 20 21:49:37 2021 daemon.notice hostapd: wlan-iot: AP-STA-DISCONNECTED a4:77:xx:xx:xx:xx
Mon Sep 20 21:49:38 2021 daemon.info hostapd: wlan-iot: STA a4:77:xx:xx:xx:xx IEEE 802.11: authenticated
Mon Sep 20 21:49:38 2021 daemon.info hostapd: wlan-iot: STA a4:77:xx:xx:xx:xx IEEE 802.11: associated (aid 3)
Mon Sep 20 21:49:38 2021 daemon.notice hostapd: wlan-iot: AP-STA-CONNECTED a4:77:xx:xx:xx:xx
Mon Sep 20 21:49:38 2021 daemon.info hostapd: wlan-iot: STA a4:77:xx:xx:xx:xx WPA: pairwise key handshake completed (RSN)
Mon Sep 20 21:49:38 2021 daemon.info dnsmasq-dhcp[2168]: DHCPREQUEST(wlan-iot) 192.168.105.131 a4:77:xx:xx:xx:xx
Mon Sep 20 21:49:38 2021 daemon.info dnsmasq-dhcp[2168]: DHCPACK(wlan-iot) 192.168.105.131 a4:77:xx:xx:xx:xx Chromecast01

Any more pointers anyone can offer, or how to provide more useful info?

I think that I've got to the bottom of this, at least for the Chromecast… I enabled firewall logging of reected packets, and spotted that just before each disconnect an ICMP type8 (ECHO) packet was being dropped. I've now allowed these packets in my firewall, and so far the Chromecast has not disconnected! :tada:

I'll try to find out if it's the same issue for the Shelly plugs in the coming days, but at least the I've fixed the Chromecast.

Any luck with this? Having the same problem with some wemo devices, neato vacuum, and nest hub. It all works for a couple days and then starts randomly dropping.

Yes. I've not had the same problem with either the Chromecasts or the Shelly plugs since allowing the ICMP ECHO packets.