Windows Server 2019 source routing must be configured to the highest protection level to prevent Internet Protocol (IP) source routing.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-205859 | WN19-CC-000040 | SV-205859r991589_rule | CCI-000366 | low |
| Description | ||||
| Configuring the system to disable IP source routing protects against spoofing. | ||||
| STIG | Date | |||
| Microsoft Windows Server 2019 Security Technical Implementation Guide | 2025-05-23 | |||
Details
Check Text (C-205859r991589_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: DisableIPSourceRouting
Value Type: REG_DWORD
Value: 0x00000002 (2)
Fix Text (F-6124r355940_fix)
Configure the policy value for Computer Configuration >> Administrative Templates >> MSS (Legacy) >> "MSS: (DisableIPSourceRouting) IP source routing protection level (protects against packet spoofing)" to "Enabled" with "Highest protection, source routing is completely disabled" selected.
This policy setting requires the installation of the MSS-Legacy custom templates included with the STIG package. "MSS-Legacy.admx" and "MSS-Legacy.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.