The audit steps are divided into general steps and specific steps. The general networking audit steps are applicable to network equipment in general, followed by specific sections for routers, switches, and firewalls. You need to work through the first section of general controls regardless of your audit and then move to the specific section you need to complete the audit.
The general networking audit steps need to be performed regardless of what networking device you audit. These steps apply to routers, switches, and firewalls regardless of what layer they operate on and regardless of where they are located in your network.
Some of the examples below are for Cisco equipment. However, the concepts quite often are applicable regardless of your equipment.