HIDS 4151

From Atomicorp Wiki
Revision as of 16:07, 21 October 2013 by Mshinn (Talk | contribs)

Jump to: navigation, search
Rule 4151
Status Active
Alert Message Multiple Firewall drop events from same source.



ASL has detected multiple attempts to access a port that the firewall has been configured by the user to block, and ASL has blocked this access. When ASL detects this has occurred multiple times, it will also shun the IP address based on the OSSEC_SHUN_TIME configured on the system.

The Linux kernel also supports stateful packet inspection. This rule can also be triggered if a connection is broken and is generating out of sequence packets. This is not a bug in ASL or in the kernel. This is exactly what stateful packet inspection is supposed to do. If you are triggering this rule on allowed traffic, please make sure you have FW_DROP_INVALID enabled for your system. This will detect these non-malicious out of sequence packets, and will ignore them.


False Positives


If you do not wish to block access to this port, please see the Tuning Guidance below.

Tuning Guidance

To configure the firewall to allow connections to this port, please see the ASL firewall documentation page.

Additional Information

Similar Rules



See this FAQ:


Knowledge Base Articles


Outside References



Personal tools