Chapter 10: Managing TCP Connections

One of the most important, yet least understood, Transmission Control Protocol (TCP) concepts is the three-way handshake. A TCP handshake initiates the connection and sets up the parameters. No data is exchanged until this process is complete. Similar to the handshake is the teardown when the two endpoints exchange a series of finis (FIN) packets, which indicates the session is complete.

In this chapter, we'll take a more detailed look at the handshake and resultant socket creation. So that you can home in on a single TCP stream, we'll take a large capture, and subset, mark, and filter the packets, so we can examine the TCP handshake. As we move through the chapter, we'll have a greater understanding of the TCP options exchanged during the handshake. We'll learn what they mean and why they are required to have a conversation on today's networks. In addition, we'll see how we can easily modify protocol preferences...