Generating program code to be used by a protocol analyzer based on definitional information relating to a data protocol. A protocol database that includes definitional information relating to characteristics of a protocol is stored. The definitional information, which is expressed in a computer-interpretable format, is processed to generate program code expressed in a programming language. The program code incorporates the definitional information and includes logic that is to be executed to interpret and analyze data packets having the protocol. In this manner, the program code to be used by the protocol analyzer is generated mechanically, without requiring software developers. When the program code needs to be updated in view of changes to existing protocols or the introduction of new protocols, the protocol database is updated. These updates are then propagated to the program code without requiring direct manipulation of the code by software developers.