LWIP TCP server (use for long time)

Hi all,

I would like to ask You about raw lwip. My tiva c is TCP server and connected client can change level on the io. This is all function. All works fine but a problem occurs after some time(sometimes three days sometimes fourteen days) any client can not connect to the server. Can be the problem in lwip stack or I have to look the mistake for somewhere elsewhere?

Thanks for your answers S.