lwip is indeed decent. At least as decent as all the C based work is which lacks any decent unit-tests to make sure it keeps working (the linux kernel is not be

lwip is indeed decent. At least as decent as all the C based work is which lacks any decent unit-tests to make sure it keeps working (the linux kernel is not better). The problem with those embedded solutions is often not lwip but that the integration and requirements between lwip, the OS and it's task system (e.g. FreeRTOS), and the actual hardware is not properly understood. Which can e.g. lead to function calls being made from the wrong context - which could work in the beginning - might lead to weird errors later on. For this reason I would also recommend people who want to build connected devices to build on top of a more mature and streamlined stack - like the Linux TCP/IP stack plus associated drivers.