We will look at some of the network and host-based software that can be used for security or sysadmin duties. We will describe what they do and instances when you might use them. We will also discuss their pricing models (all are free for basic usage but scale up in cost for more advanced use). We will look at Nmap (and Zenmap), Nessus, Nagios, Snort, ClamXav, Wireshark, tcpdump and tcpflow, BroIDS, Splunk, and maybe more. We will cover a lot of material very fast, so this will be a high level introductory view.