Snort 2.9.5.5 發布，入侵檢測系統

Snort是美國Sourcefire公司開發的發布在GPL v2下的IDS（Intrusion Detection System）軟件

Snort有 三種工作模式：嗅探器、數據包記錄器、網絡入侵檢測系統模式。嗅探器模式僅僅是從網絡上讀取數據包并作為連續不斷的流顯示在終端上。數據包記錄器模式把數 據包記錄到硬盤上。網路入侵檢測模式分析網絡數據流以匹配用戶定義的一些規則，并根據檢測結果采取一定的動作。網絡入侵檢測系統模式是最復雜的，而且是可 配置的。

Snort可以用來監測各種數據包如端口掃描等之外，還提供了以XML形式或數據庫形式記錄日志的各種插件。

發布說明: This release fixed an issue with the SMTP preprocessor and the ignore_tls_data configuration correctly stopping inspection after an SMTP session is encrypted. All rule evaluation (as opposed to just rules with fast patterns) is now disabled for packets on a previously blocked session. The perfmon preprocessor now writes stats as soon as both the time and packet count criteria are met. The same restrictions are enforced on relative PCRE for HTTP buffers from shared library rules as already existed with text rules