The 6to4 IPv6 transition technology must be disabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-26575	WN12-CC-000007	SV-52970r1_rule		Medium

Description
IPv6 transition technologies, which tunnel packets through other protocols, do not provide visibility.

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

Details

Check Text ( C-47276r1_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: \Software\Policies\Microsoft\Windows\TCPIP\v6Transition\ Value Name: 6to4_State Type: REG_SZ Value: Disabled

Fix Text (F-45896r1_fix)
Configure the policy value for Computer Configuration -> Administrative Templates -> Network -> TCPIP Settings -> IPv6 Transition Technologies -> "Set 6to4 State" to "Enabled: Disabled State".