Error response codes

[BlueAndi]

This is not a bug report, just for information, because it confused me and may help others.

LwIP uses its own errno.h which provides error codes with a different meaning than the one from idf.
This confuses in case you try to analyze the reported errors.

I found this, which confirms it: espressif/esp-idf#8546 (comment)

Example:
If you try to connect to a host, which doesn't exists, the error 113 is reported.
The provided errno.h for Arduino v2.x provides "Software caused connection abort" for 113, which is wrong. It should be "Host is unreachable".