Security software developers have a long history of making their work available for free. Here's a small taste, keeping in mind a few caveats, like uncertain support or limited capabilities relative to paid products. One of the biggest "free" segments in security is antivirus freeware, such as that from Avira and Avast, as well as Microsoft Security Essentials, which got rave reviews in the June issue of Consumer Reports this year. However, the popular magazine also advised that "pay suites" for desktop malware are more full-featured and easier to use.BACKGROUND: Consumer Reports: Free anti-malware for Windows, Mac is effectiveAnother type of free security software is a desktop firewall offered by ZoneAlarm. A When does free mean none? Free security products out there for the asking Six Free Cisco Labs Apprenda wants you to build your apps for the cloud ... for free The A\/V freeware genre is huge but it's mainly consumer-oriented. However, there are plenty of sophisticated tools the corporate network manager can try. Among them:The Arpwatch bandwidth monitoring tool; Cheops, the network tool mapper; Hydra network login cracker to test for weak passwords; SNMP Brute, a tool for brute-force password attacks; the Wireshark open-source packet analyzer; and Kismet, a wireless network detector, sniffer and intrusion-detection system.After all, if hackers get to play with these for free to try and overpower your network defenses, why shouldn't you find out what they can find out?Some now-classic selections in the security freeware category are the Metasploit Framework open-source penetration testing tool, which is also commercialized by Rapid7; the NetCat mapping tool; the Nessus remote-security scanner; NetStumbler wireless network discovery tool; the nMap Security Scanner; and of course, Snort, the intrusion-detection and prevention system pioneered over at Sourcefire.In addition, security vendors that want to get your attention are known to come up with lots of tools like free assessment scans of one sort of another, though the end goal of course is usually to sell you a subscription service.Among the vendors that regularly announce free scans are Qualys for vulnerability assessment, eEye, Sophos, Symantec and McAfee. Microsoft has long offered its free Microsoft Baseline Security Analyzer, mainly for small to midsize businesses to check Windows for conformance with Microsoft security recommendations. However, it appears that Microsoft won't offer the tool for Windows 8.Ellen Messmer is senior editor at Network World, an IDG publication and website, where she covers news and technology trends related to information security. Twitter: @MessmerE. Email: firstname.lastname@example.org.Read more about wide area network in Network World's Wide Area Network section.