Some help is often better than none (especially when its free) so lets give some attention to the built-in set of Intrusion Detection mechanisms. When enabled, ISA will identify when an attack is attempted against your network and performs a set of manually configured alerts in case of an attack. To detect unwanted intruders, ISA Server compares network traffic and log entries to well-known attack methods. Suspicious activities trigger alerts. Actions include connection termination, service termination, e-mail alerts, logging, and others.