There are a lot of people or there with a lot of opinions on fancy and expensive security tools which they beleive are required to ensure network security.
It is my opinion that a lot can be done to ensure a secure network with free and open source tools.
Spiceworks cans be installed on a spare pc and perform inventory and patch analysis. Spiceworks.com
Trisul us a software package that runs on Linux and can monitor network traffic.
Trisul.org
Untangle can be installed on a system to provide a enterprise grade firewall.
Untangle.com
And Microsoft Security essentials us a free anti-virus software from Microsoft
While you can spend thousands to millions on commercial software an support, there are open source and free alternatives.
Russ Dyer. CISSP CRISC
Security Analyst and Mobile Device Evangelist
