This question presupposes two things. The first is that you are familiar with networking and the systems and components it contains. The second is that your knowledge is sufficient to describe the different types of firewalls used within a network topology. As a senior technical support engineer, you are expected to know a broad range of computer systems, software, and technology. Since networks are a critical component of any organization's IT infrastructure, you need to be intimately familiar with the technology they employ and any issues that may occur and that you need to address. Obtaining additional advanced Cisco network certifications will further enhance your qualifications.