A penetration tester begins an engagement by performing port and service scans against the client environment according to the rules of engagement. Which of the following reconnaissance types is the tester performing?

The tester is performing active reconnaissance because they are directly interacting with the target system by sending network traffic (port and service scans). This interaction can be detected by the target. Passive reconnaissance involves gathering information without directly engaging the target, such as OSINT (Open-Source Intelligence) or sniffing publicly available traffic. Defensive and offensive are broad categories of security operations, not specific types of reconnaissance. While penetration testing is an offensive security activity, "offensive" isn't a type of reconnaissance in this context.