Nmap can be utilized to perform UDP, TCP stealth, TCP connect, and zombie scans. In this section, we will discuss how to conduct each of these types of scans. The Nmap approach to UDP scanning is more complex and attempts to identify live services by injecting service-specific probe requests in an effort to solicit a positive response that confirms the existence of a given service. We will also discuss how Nmap handles stealth and TCP connect scanning. Finally, we will look at a highly effective scanning mode Nmap has for zombie scanning.