The system must be configured to limit how often keep-alive packets are sent.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
WN12-SO-000041	WN12-SO-000041	WN12-SO-000041_rule		Low

Description
This setting controls how often TCP sends a keep-alive packet in attempting to verify that an idle connection is still intact. A higher value could allow an attacker to cause a denial of service with numerous connections.

STIG	Date
Microsoft Windows Server 2012 Domain Controller Security Technical Implementation Guide	2013-07-25

Details

Check Text ( C-WN12-SO-000041_chk )
If the following registry value does not exist or is not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \System\CurrentControlSet\Services\Tcpip\Parameters\ Value Name: KeepAliveTime Value Type: REG_DWORD Value: 300000 (or less)

Fix Text (F-WN12-SO-000041_fix)
Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> "MSS: (KeepAliveTime) How often keep-alive packets are sent in milliseconds" to "300000 or 5 minutes (recommended)" or less. (See "Updating the Windows Security Options File" in the STIG Overview document if MSS settings are not visible in the system's policy tools.)

Fix Text (F-WN12-SO-000041_fix)

Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> "MSS: (KeepAliveTime) How often keep-alive packets are sent in milliseconds" to "300000 or 5 minutes (recommended)" or less.

(See "Updating the Windows Security Options File" in the STIG Overview document if MSS settings are not visible in the system's policy tools.)