jamesindc wrote: » Which of the following would a network administrator MOST likely use to actively discover unsecure services running on a company's network? a. IDS b. Nessus c. NMAP d. Firewall I chose b. Nessus, but the answer is c. NMAP. Can someone please explain the difference so I can answer Nessus / NMAP questions correctly on the Network+ exam I'm taking next week? Thank you!