Network Security

Question 1

What is the difference between Nmap and Nessus?

NMAP has set the industry standard for port scanners and does three things.

  1. Ping hosts to determine if they are alive or not.
  2. Portscan hosts to determine what services are running.
  3. Try to determine the OS of the hosts.

Nessus is an open-source vulnerability scanner based on client server technology. Nessus includes many port scanning tools one of them being nmap. Although Nessus has nmap as a module, nmap is no longer the default scanner, and nmap must explicitly be chosen if one want to use it.