port reuse

Hello,

I have a simple server application. I am using port 2178 for listening a
client. If I close server application and reopen it I can immediately open
port again for listening. If application is crashing (windows exception, then
it is closed by OS) sometimes I can’t open port for listening. Please, advise
me on possible causes of the problem.
If this is a wrong group for the question, please direct me to the right
group.

Thanks.