I use EVK1100 in AT32. In this project, we using RTOS+LWIP. 

we have implemented the TCP/IP using default files. what problem we are facing in the

project is that our TCP can listen the sockets only three times thereafter if we try to open the port it won't open. then we have to restart the system.

So We want to know

is any TCP/IP listen limitation in lwip?

if any limitation are there how can we overcome the issue?

Please anybody help for us?