Safety Snort

R ecently, I implemented an Intrusion Detection System (IDS) for a remotely hosted web farm. After the initial setup, I began testing and configuring to streamline the system. As soon as the system was switched on, I noticed the sort of traffic that shouldn't be internal to a DMZ. The ISP-controlled firewall had been misconfigured to allow almost all traffic.

In the short time the test was running, the IDS logged a large number of port scans and access attempts on the main servers. From these logs, it was obvious that the servers were receiving the wrong sort of attention.

The moral of the story is to keep an eye on your network. Even if you don't have a misconfigured firewall, your systems could benefit from the attention of an IDS. At the most basic level, an IDS captures network traffic. Then it compares the contents of these packets against specific rules to check for known vulnerabilities or malicious code.

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