With an STM32 board with Ethernet compatibility, this library allows a STM32 board (NUCLEO, DISCOVERY, ...) to connect to the internet.

For more information about this library please visit us at http://www.arduino.cc/en/Reference/Ethernet

The library is based on LwIP, a Lightweight TCP/IP stack.
http://git.savannah.gnu.org/cgit/lwip.git The LwIP has been ported as Arduino library. The STM32Ethernet library depends on it.

EthernetClass::maintain() in no more required to renew IP address from DHCP.
It is done automatically by the LwIP stack in a background task.

An Idle task is required by the LwIP stack to handle timer and data reception. This idle task is called inside the main loop in background by the function stm32_eth_scheduler(). Be careful to not lock the system inside the function loop() where LwIP could never be updated. Call Ethernet::schedule() performs an update of the LwIP stack.

You can find information at https://github.com/stm32duino/wiki/wiki/STM32Ethernet