Extra Functions Introduction This documentation is about extra functions, that are not necessary to get it running, but can be used if need be. Non-deprecated functions ETH_setup_MAC_address_filtering This function is used for perfect mac address filtering. It is used by giving it MAC-addresses as arguments. If you receive packets with those addresses, they will also be processed. Deprecated Functions There are deprecated functions for raw sending ( ETH_raw_send ) and custom protocol receiving ( ETH_custom_protocol_receiver ). Those can be used if you don't want to use UDP, but I don't know if they still work. Raw receiving If you want to receive messages, you need to have #define LWIP_HOOK_UNKNOWN_ETH_PROTOCOL(pbuf, netif) eth_reader(netif, pbuf) in the cubemx_main.h file.