Title

The system must set maximum number of half-open TCP connections to 4096. (Cat II impact)

Discussion

This setting controls how many half-open connections can exist for a TCP port. It is necessary to control the number of completed connections to the system to provide some protection against denial of service attacks.

Check Content

Determine if the number of half open TCP connections is set to 4096. # ipadm show-prop -p _conn_req_max_q0 -co current tcp If the value of "4096" is not returned, this is a finding.

Fix Text

The Network Management profile is required Configure maximum TCP connections for IPv4 and IPv6. # pfexec ipadm set-prop -p _conn_req_max_q0=4096 tcp

Additional Identifiers

Rule ID: SV-216141r603268_rule

Vulnerability ID: V-216141

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.