Developing a Valid UDP Layer Response

Introduction

The IP header of a network packet defines the sender and the intended recipient. However, many different applications can be running and communicating over the network on a single computer.

TCP and UDP define the concept of ports, which allow a network packet to be directed to a particular application running on a computer. When creating a response to a received request, we need to craft a TCP or UDP header that matches the received response.

Defining a UDP response header

TCP and UDP headers have some overlap. They both define port values in a similar way. However, the two protocols also contain different header values.