Port Scanner

Mission

The purpose of this exercise is to be able to scan open ports on a host.
This could be done as either a White-Hat attack, or a Black-Hat attack. What is the difference?
You should only scan for open TCP ports, not UDP.
Why is it more difficult to scan UDP ports?

Part 1: Simple Port Scanner (TCP)

Create a new console application project.
Either hardcode a destination or ask the user for an IP-address. (First time could just be localhost / 127.0.0.1)
Implement a for loop that goes through all available ports (How many? Hint: 16bit).
For each port, create a TcpClient with the IP-address and the port number.
If it throws an Exception, the port is not in use.
If it doesn’t throw an Exception, remember the port number (in a list?)
Show the open ports in the console.

Part 2: Using Threads:

Now the speed of your port scanner is probably not very impressive.
Why is it so slow?
One way to make it faster is to use threads.
How would you implement this? One thread per port, or multiple ports per thread?
How will you show the open ports in the console when using threads?