
Network Analysis using Wireshark Cookbook
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TCP and UDP are the main protocols in layer 4 that provide connectivity between end applications. Whenever you start an application from one side to another, you start the session from a source port, usually a random number equal or higher than 1,024, and connect to a destination port, which is a well-known or registered port that waits for the session on the other side. These are the port numbers that identify the application that works over the session.
Other types of filters refer to other fields in the UDP and TCP headers. In UDP we have a very simple header with very basic data, while in TCP we have a more complex header that we can get much more information from.
In this recipe we will concentrate on the possibilities while configuring TCP and UDP display filters.
As done earlier, we should plan precisely what we want to display and prepare the filters accordingly.
For TCP or UDP port numbers use the following display filters:
tcp.port == <value...
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