Airjs could not sync. : Error: Retransmit counter exceeded

[gschintgen]

Hi, I'm having trouble with the connection. The node-red host can ping the purifiers (1214 and 3033) just fine, but it can't establish a connection.

After I hit deploy, the node's status is "Trying to connect", then after 15 seconds (1214) there are two messages in the debug log: "Airjs could not sync. : Error: Retransmit counter exceeded" and "AirJS observe failed." and after 20 more seconds the same two messages are printed for the 3033. (And both then have a status of "disconnected")

(nodered and philips-airjs are up to date, a "ping" node in nodered works just fine and shows that the purifier is indeed reachable on the network.)

Maybe there has been a recent firmware update (as hypothesized in #9 by @dg0ojo)?
AC1214 has Wifi 73.1 and Device firmware 2.0.0. (hmm, x.0.0 that could mean trouble indeed?).
AC3033 has Wifi 73.1 and device firmware Ms3331.

Is there anything else I could check?

[dionmes]

Hi, I am now not in the situation to check it. But after the previous comment I did check and update the air purifier. For me it still worked, will try to investigate a bit more this weekend.

[gschintgen]

There seems to be an issue with dns/IPv6.

My purifiers are reachable as philips-ac1214 or philips-ac1214.lan and philips-ac3033 or philips-ac3033.lan via my lan's dns server. This also works fine on my node-red's host command line interface and as hostname of "ping" node in node-red. But it does not work for Airjs, which is only working "observing" correctly when I specify the IPv4 address.

I also tried entering the IPv6 address in the Airjs node and this does not work. So maybe the purifiers only listen on IPv4 or their coap service only works correctly with IPv4 but Airjs's/nodered's hostname resolution by default returns the purifier's IPv6 address (as it should).

[dionmes]

Thanks @gschintgen , that's some good info. I tried some things but indeed I see some weird resolvement issues with dns. Although my IP knowledge is a bit rusty. Current workaround is using the IPv4 address directly, but that is not ideal.
So the thing that I can change is updating the node-coap-client . I see there is a new version (2.1.0), although the version I am using now 2.0.2 should be able to use IPv6 correctly.