A port scanner (such as nmap) is a piece of software designed to search a network host for open ports. Cracker can use nmap to scan your network before starting attack. You can always see scan patterns by visiting /var/log/messages. But, I recommend the automated tool called psad - the port scan attack detector under Linux which is a collection of lightweight system daemons that run on Linux machines and analyze iptables log messages to detect port scans and other suspicious traffic.

psad Tutorial: Detect And Block Port Scan Attacks In Real Time

The Social Accessibility Project is a service whose goal is to make Web pages more accessible to individuals with disabilities. Users encountering Web access problems can report these problems to the Social Accessibility server. Volunteers are notified and respond by creating and publishing the requested accessibility metadata.

Today's ISP environment requires authenticated SMTP to be able to send emails. As a policy, authenticated SMTP helps cut down on folks sending SPAM and allows the ISP to track which account is sending what type of email content for further demographic study. While authenticated SMTP is good for the ISP, it is not a configuration supported out of the box by most Linux distributions. This means that all those system emails and log reports emailed by root never make it anywhere anymore.

http://www.howtoforge.com/exim-authenticated-smarthost

Discover MBeanInspector for WebSphere Application Server, a Java Management Extensions-based administration program for WebSphere 5. MBeanInspector is a useful testing tool; it allows users to examine MBean attributes, invoke MBean operations, and listen for MBean notifications.

Diagnose problems in WebSphere deployments using the Trace Analyzer for Websphere Application Server, a graphical environment for analyzing trace logs in detail. As WebSphere is deployed in increasingly complex environments, oftentimes the only way to solve problems is to create trace logs to show the sequence of events leading to the problem.