[Resolved] Unable to receive UDP multicasts

[mh-dev]

No device is using the 5G AP.

I don't really think that the dual band AP is the problem since the ESP is able to continue to receive message after I enable the 5G again. Only seems to stop working again when I perform a hard reset.

[WiFive]

So if you leave 5g disabled and reset the device it still has a problem? Or only reset when 5g enabled? Seems like some problem with igmp registration and the ap. Have you tried the mdns example to make sure it isn't something in your code or the sockets api? I think mdns uses lwip raw api.

[mh-dev]

I tested the mdns example and it seems to do something. I did not check what its doing in detail, but the log contained my printer. So I consider this example as working.

Procedure (all based on my normal AP mobile phone AP is not into play anymore)

• Disable 5G net
• Connect ESP to 2.4G net
• Multicast working
• Enable 5G (forces a restart of the 2.4G net too)
• Press reset button my my dev board
• Multicast still working(I repeated this a few times)
• Remove power for a few seconds (remove USB cable from dev board)
• Multicast not working anymore( can not guarantee that this is repeatable scenario I can perform further tests if necessary)

The code except the wifi part is on page1. The wifi code is the similar to the one in the mdns example, except that I use a callback instead of a sync bit.

[WiFive]

You're not really doing anything to narrow it down.

• Disable 5G net
• Connect ESP to 2.4G net
• Multicast working
• restart ap without enabling 5g
• Press reset button my my dev board
• Multicast still working?
• Remove power for a few seconds (remove USB cable from dev board)
• Multicast not working anymore?
• restart ap without enabling 5g
• Multicast working?
• Press reset button my my dev board
• Multicast working?

Try above with both your code and mdns. Any difference?

[mh-dev]

Performed the described scenario and both were working at all times.

Did some additional tests afterwards and tried to get the multicast back to a not working. I enabled 5G again.
I was unable get a consistent scenario how to get it back to error state. Did erase the flash, rest it and also removed it for a few seconds from the power supply. None of them brought it back to error state.
At the end I got it back into error state after it was unplugged from the power supply for a few minutes, while I was testing something with the other board.
This might only have been a coincidence.

I repeat the scenario tomorrow again with a longer duration without power supply at the corresponding steps and see if I can build a consistent scenario with it. I am not sure if it should make any significant difference between a few seconds without power supply and a longer duration.

[mh-dev]

I did various tests and could track that problem down to the AP.
I have no clue what this AP is doing, but I am pretty sure that this firmware has problems. Later on I was able to force the problem with my normal desktop. Checking via Wireshark that IGMP refresh requested gets replied, but still it seems that the AP is ignoring them.

Apologize for the confusion. At least I am learned that there are tons of problems out there related to access points.

[WiFive]

Glad to know your findings. Do you want to post the model and firmware version of the AP for reference?

[mh-dev]

Its a Hitron CGNM0-2250 hardware revision 1A with the firmware 4.5.10.40

Test scenario:
Two computers both wait for Multicast message and send every 10 seconds a message. After a while the computers stop receiving message from the other computer.
Alternative listen for SSDP(UPNP) multicasts and this stops too after a while.
'a while' means an undefined amount of time between zero and infinity. Saw it after 5 mins but also for longer duration's.
The only way to get it running again was restart the AP. A Computer restart was not enough.