Hi,
I want to implement keepalive on connected socket between 2 machines , that
can be behind NAT.

I saw the
SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, 1)

and the IOControlCode.KeepAliveValues options.

But I didn't found article that explain how to use it.

1. both machines need to call those methods?

2. what the difference between the setsocketoption and the IOControl option
, and I need to use both , or only one of them ?

3. There is difference if I call those method before I connect the sockets
or after ?

4. there is difference if I am behind NAT ?

5. how to use the IOControl ? (syntak , values)

In general , there is good article about those issues ?

thanks a lot