The system must be configured to prevent Internet Control Message Protocol (ICMP) redirects from overriding Open Shortest Path First (OSPF) generated routes.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-4111	WN12-SO-000039	SV-52925r1_rule		Low

Description
Allowing ICMP redirect of routes can lead to traffic not being routed properly. When disabled, this forces ICMP to be routed via shortest path first.

STIG	Date
Windows Server 2012 / 2012 R2 Domain Controller Security Technical Implementation Guide	2016-12-19

Details

Check Text ( C-47230r2_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: EnableICMPRedirect Value Type: REG_DWORD Value: 0

Fix Text (F-45851r2_fix)
Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> "MSS: (EnableICMPRedirect) Allow ICMP redirects to override OSPF generated routes" to "Disabled". (See "Updating the Windows Security Options File" in the STIG Overview document if MSS settings are not visible in the system's policy tools.)