OL 9 must not enable IPv6 packet forwarding unless the system is a router.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-271880 | OL09-00-006043 | SV-271880r1092352_rule | Medium |
| Description |
| IP forwarding permits the kernel to forward packets from one network interface to another. The ability to forward packets between two networks is only appropriate for systems acting as routers. |
| STIG | Date |
| Oracle Linux 9 Security Technical Implementation Guide | 2025-05-08 |
Details
| Check Text (C-75930r1092350_chk) |
| Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Verify that OL 9 is not performing IPv6 packet forwarding, unless the system is a router. Check that IPv6 forwarding is disabled using the following commands: $ sysctl net.ipv6.conf.all.forwarding net.ipv6.conf.all.forwarding = 0 If the IPv6 forwarding value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
| Fix Text (F-75837r1092351_fix) |
| Configure OL 9 to not allow IPv6 packet forwarding unless the system is a router. Add or edit the following line in a single system configuration file in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.forwarding = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |