How to Test a Network Application with only a Single Computer?

I want to kick myself to learning network programming, starting with implementing existing network protocols. I've finished the (rudimentary) design and will start coding soon. The problem I haven't been able to figure out solution to is related to testing: I only have开发者_开发技巧 one Windows laptop running Windows 7 Pro with only a recovery disc (no installation disc) that obviously cannot be used on a VM.

Hard-coding input/output data clearly isn't a good way to test any sort of program. So, what solutions can I look into?

Thanks for your time.

P.S.: In case this matters, I'll do the coding in C++.

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You can run a client and a server on the same machine. When accessing the network layer, just use the local callback loop (127.0.0.1 for ipv4 or ::1 for ipv6) to connect to your server when you run the client.

If you provide the APIs that you will be using (wininet, APR, Boost etc) a more detailed answer would be available.

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What about a VM with Ubuntu or some other distro of Linux?