OL 9 must not enable IPv6 packet forwarding unless the system is a router.

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.

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.

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