3.1.1 Ensure IP forwarding is disabled (sysctl.conf/sysctl.d)

Information

The net.ipv4.ip_forward flag is used to tell the system whether it can forward packets or not. Setting the flag to 0 ensures that a system with multiple interfaces (for example, a hard proxy), will never be able to forward packets, and therefore, never serve as a router.

Solution

Set the following parameter in the /etc/sysctl.conf file: net.ipv4.ip_forward = 0 Run the following commands to set the active kernel parameters: # sysctl -w net.ipv4.ip_forward=0# sysctl -w net.ipv4.route.flush=1

See Also

https://workbench.cisecurity.org/files/1866

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(12), CSCv6|11

Plugin: Unix

Control ID: 87cc573dc1dd2f6f57d551df633934ead8eb8da61e6ceb4a48cc2afbfc20222a