The system must be configured to use TCP syncookies when experiencing a TCP SYN flood.

From AIX 5.3 Security Technical Implementation Guide

Associated with IA controls: ECSC-1

Associated with: CCI-001092

SV-38803r1_rule The system must be configured to use TCP syncookies when experiencing a TCP SYN flood.

Vulnerability discussion

A TCP SYN flood attack can cause Denial of Service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies are a mechanism used to not track a connection until a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This technique does not operate in a fully standards-compliant manner, but is only activated when a flood condition is detected, and allows defense of the system while continuing to service valid requests.

Check content

Fix text

#/usr/sbin/no -p -o clean_partial_conns=1

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.