Airlink - Disconnection Station Timeout

[jasonmfarrow]

I've a problem with the Airlink and Metobridge.

According to the Davis Weatherlink App my Airlink is working on the static Ip addres I've assigned and sending data to the web.
According to my network the Airlink is ping-able and using a python script or a web browser can use the

Code: Select all

http://<ipaddr>/v1/current_conditions

to query the device on my local network.

However, Meteobridge (NanoSD) log is showing

No synchronisation for 900 seconds - Disconnect Station 1 - Timout

I can fix the Airlink for a while with a reboot of the Airlink, and Meteobridge duly reconencts, but after a variable number of hours the Meteobridge-Airlink connection will fail.

Meteobridge: 5.8 (Feb 23 2024 build 4758) FW 1.4
Airlink: firmware 21st October 2020.

Anyone know whether this is a problem that has a firmware fix or is my Airlink about to fail?

[davidmc36]

All I can say is that my Airlink stays connected on my MB running 6.2. I have never actually set the IP to static. But it reconnects at same address whenever it or WiFi power cycles.

I had a lot of trouble before running two WiFi systems.

Now I only have one network with the mesh nodes in bridge mode and router WiFi turned off.

ALL my devices connect better now that network is "cleaner".

[davidmc36]

Do you know how the signal strength is?

[AA5H_AX088]

- Or perhaps interference. The Davis Airlink isn’t very robust and has no Forward Error Correction, just a CRC check; packet error will cause retransmissions and jitter, once the jitter threshold is exceeded the the receiver will report down. Can you move the Airlink temporarily to another location.

- are you running a mesh system with the same SSID? I had a problem before where a device would flap between two mesh wireless nodes continually. Amazon EERO nodes are especially bad with this.

- Do your wireless nodes run dual or tri band? Can you set one node to allow a dedicated 2.4 mHz guest network just for the Airlink? Sometimes 2.4gHz devices will attempt to pair with 5gHz on the same SSID, especially if the signal is strong, the 2.4 sees the harmonic freq from 5gHz and gets confused.

-one last thing, but not likely, is time synchronization. Can you ensure the devices are all using the same time source?

Just a few things to try.

[jasonmfarrow]

I have specifc 2.4GHz networks for all my weather related kit [Separate SSIDs for 5GHz traffic]. All wifi SSIDs use the same private subnet. Both the Meteobridge and Airlink use static IPs addresses. The Airlink Wifi Rssi is ~61dB and both the Airlink and Meteobridge are using the same access point. There is a mesh extension but both are connecting to the primary. Both devices have been operational for years on the same SSIDs and underlying networking. It is only recently that the meteobridge-airlink connection has been less than 100%.

There is no way to set a NTP source for the Airlink or Meteobridge NanoSD of which I am aware. They do appear to be in sync for time.

[davidmc36]

....

- are you running a mesh system with the same SSID? .....

That caused me a world of grief. All runs smooth now with nodes in bridge mode.

[AA5H_AX088]

....

- are you running a mesh system with the same SSID? .....

That caused me a world of grief. All runs smooth now with nodes in bridge mode.

Amen…. When on mesh our iPads and iPhones would get stuck on our bedroom WAP, and slow to a crawl in our living room that has its own AP. We had to turn off and re-enable to get them to pair with the closest AP. Eero are generally good for single a small home or apartment, but large homes with meshed nodes are terrible. Commercial mesh systems work great, they have a central server making the decisions.

[AA5H_AX088]

I have specifc 2.4GHz networks for all my weather related kit [Separate SSIDs for 5GHz traffic]. All wifi SSIDs use the same private subnet.

Jason, good job checking the boxes, let me throw out a few more:

Firewall? Even intra-Vlan traffic may pass though a firewall, especially if ARP is suppressed. I am running a PFSense firewall with Snort IDS, it flags my weather infrastructure devices all the time and blocks them as a rogue device. Most IDS software will unblock the traffic after a set period, allow some traffic to flow, and block them again, rinse-repeat. I had to create a special device group and ruleset for all my weather stuff. Not all the traffic will be blocked, firewalls and IDS systems will find the certain ports that it finds suspicious and only block them which makes it difficult to troubleshoot.

Interference: since this worked before, has any new devices capable of RFI been installed near the Airlink? Meteobridge is more tolerant to jitter and can recover from packet loss, Davis Instruments not so much. Davis Instruments uses an el-cheapo wireless receiver, probably to keep their per-unit costs down, it has no error correction and not much packet buffering if packet errors occur. My $15 Ecowitt hub is faster and more reliable than their expensive white box.

Any new IOT devices near the device, IOT dimmer switches are notorious for rfi? Any of those cheap Chinese gadgets like room fans and LED lights are horrible as well, none use any filtering. Computer monitor cables, and the monitors themselves are rfi pigs. The worst offenders of all are those cheap wall wort chargers and dc power supplies. Get them away from the gateway, or at least install some of those snap on ferrite suppressors.

Hope that helps, probably not smoking gun solutions, but worth a try.


Are you familiar with wireshark, it’s a free packet sniffer. You can capture the traffic on your VLAN, filter on the Gateway IP, and look for packet errors.

[davidmc36]

For the benefit of anyone searching, whether applicable to the OPs issue or not, I had the main mesh node wired to ISP router and everything transmitting the same SSID.

Just chaos.

Turned OFF the WiFi on ISP router, set nodes to bridge mode, transmitting the original SSID and PWD.

Everything connects smooth and retains full signal switching seamlessly from one node to the other. Interestingly, I have the "Facilitate Fast Transfers Between Nodes" feature turned off in the node GUI. It does warn that some devices are not compatible with that feature.

I am transmitting 2.4 and 5 GHZ modes from the nodes.

They are Nova devices. Up to WiFi 6 capable I believe.

[AA5H_AX088]

David, agreed. Mesh is just a huge mess. Each vendor has proprietary mechanisms, and IEEE has no established standards beyond the recommendation stage. Even worse, if you have any Google NEST or Amazon Alexa devices, thier vendors allow them to join in act as mesh nodes.

I turned bridge mode on as well, mostly to prevent the mesh nodes from assigning their own IP addresses.

[jasonmfarrow]

Firewall?
Interference: since this worked before, has any new devices capable of RFI been installed near the Airlink?
Any new IOT devices near the device

Firewall: Nope all local LAN traffic is unrestricted. No "Zero Trust" here.

Interference: The only new item is a Raspberry Pi 5 which is now sitting in a PironMan5 mini. [This does have some LEDs]. This is near my Airlink and I can move it further away as an experiment.

IOTs: No new IOTs (unless you count the RPI5 running Home Assistant OS headerless)

FYI: The Airlink-2-Meteobridge link disconnected from about 22:10 yesterday to 05:41 today when it magically reconnected with no changes to anything overnight. Really puzzling and really annoying!

[admin]

The Airlink-2-Meteobridge link disconnected from about 22:10 yesterday to 05:41 today when it magically reconnected with no changes to anything overnight. Really puzzling and really annoying!

Just to understand it fully... Meteobridge NANO ist still operational in the network (can upload data to the Internet, can be accessed via the HTTP GUI) while connection to the Airlink does stall?

NANO does not try to reestablish the connection to the Airlink once being disconnected?

[jasonmfarrow]

Hi Admin.

The Meteobridge NanoSD is GOOD. It's sending out data to everything as expected. [Nb. Windy and Meteomap seem to be dead at the moment, but that's not the topic here.]

The issue is the sometime drop in connectivity between the Airlink and Meteobridge...even though Airlink continues to send to Davis' WeatherCloud using the very same local wifi. Said Wifi has been stable for months (if not years).

A reboot of the Airlink results in an instant reconnection to Meteobridge. Last night the log showed a drop and, 7-hrs later, a reconnect without the need to reboot the Airlink.

I just cannot pin down the issue. Airlinks can reportedly fail and they only have a 1-yr warranty. Mine was purchased in 2020 so supposedly it's lasted well? But, can I guarantee a new Airlink will solve the issue? Not right now.

[Mattk]

Airlink doesn't like being too far away from the AP. Is that any great distances involved?

The Airlink connection is to AP, same as the NanoSD is to the AP, there is really no direct link (as such) between the Airlink and Nano

[admin]

A reboot of the Airlink results in an instant reconnection to Meteobridge. Last night the log showed a drop and, 7-hrs later, a reconnect without the need to reboot the Airlink.

Thanks for giving that detail. I checked the Airlink read out code on the NANOs:

Code: Select all

#!/bin/sh
#
while :
do
  wget -q -t 1 -T 20 -O- "http://$2/v1/current_conditions"
  sync
  sleep 10
done

I had some issues with ambient weather IP devices in the past that also had their data readout via a HTTP GET request. The issue there was related to HTTP requests being answered slower and slower over time. I guess this was because of a memory leak in the firmware of the device. As a result the device gets more and more unresponsive on their web interface until it finally stalls. New FW helped to solve this for the ambient device.

If someone knows of a reboot command that can be issued to the Davis Airlink over HTTP, I could trigger this when wget runs into timeouts while waiting for Airlink to reply. The 20 seconds timeout in the wget code should be fine. I doubt that waiting longer will solve it.