ESP32 Ethernet Crashing whole LAN

[aaquilina]

Has anyone ever encountered an issue where the ESP32 hangs completely (the log output stops mid timestamp) and crashed the entire LAN network? By this I mean, no computer on the same LAN can access either the internet nor the local server for files?

In the case that no one has, anyone has any suggestions as to what can cause such an issue? As soon as I unplug my ethernet board everything goes back to normal so I'm quite confident that its the ESP32. Furthermore, the hang happens randomly so its somewhat difficult to recreate. I'm quite confident that there should be some checks on the DHCP server side/ router side to prevent malicious attacks such as this.

[ESP_igrr]

Would be very interested in the steps to reproduce, or any clues related to network setup/equipment. If anything, that's a very neat undocumented feature </espressif hat off>

[aaquilina]

I'll try find out what steps reproduce it this week.

[kurtzweber]

it would be very useful if you also could share your network topology... I mean the devices (routers, switches, APs...) that "builds" your network.

thanks

[aaquilina]

I found the function that was crashing the network. For some reason it was the failed creation of a task to handle my serial comms. However, I dont know what that has to do with the network. Don't know router models cause i dont have physical access to that room.

As a temporary fix, I'm resetting the esp in software before it hangs.

[andrbmgi]

Ever since tinkering with any of the ESPs I had this issue. Sometimes it would work but especially high traffic applications killed my router every single time. Only a reboot fixed it.
I read about there being a bug with mode n networks that can lead to those crashes. I changed my routers mode to g only and the crashes seem to be gone.

[Mr_Red]

I've encountered similar issue recently. Seems related to Ethernet flow control. See this post: https://www.esp32.com/viewtopic.php?t=6948
The ESP can get stuck sending pause frames for some reason. Disabling flow control on PHY and MAC seem to prevent it.