This directory contains generic network interface device drivers that do not contain any hardware or architecture specific code. The files are: ethernet.c Shared code for Ethernet based interfaces. lowpan6.c A 6LoWPAN implementation as a netif. lowpan6_ble.c A 6LoWPAN over Bluetooth Low Energy (BLE) implementation as netif, according to RFC-7668. slipif.c A generic implementation of the SLIP (Serial Line IP) protocol. It requires a sio (serial I/O) module to work. ppp/ Point-to-Point Protocol stack The lwIP PPP support is based from pppd (http://ppp.samba.org) with huge changes to match code size and memory requirements for embedded devices. Please read /doc/ppp.txt and ppp/PPPD_FOLLOWUP for a detailed explanation.