3.1.1 Ensure IP forwarding is disabled - sysctl

Information

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/1856

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7, CSCv6|3, CSCv6|11

Plugin: Unix

Control ID: fc3324e71af06ddcae690de6ec7e9a8bb2cdec9ec01ca8f2b19d57514a2c21c5