I am working on the TCP Client and Server for K64F.
The lwip ping, hdcp example from SDK is done on the FRDM-K64F board.
However, where can I get the example for TCP client and server code ?
From our SDK you could refer to lwip_tcpecho and lwip_httpsrv examples.
In the Brief Introduction to LwIP stack in MCUXpresso SDK you will find the description of the Lwip stack API and a overview of the available Lwip examples.
I recommend you take a look the following community posts with similar inquiries.
I apologize for the delay on my reply.
If I can help further, please let me know.