7.1.1 Disable IP Forwarding

Information

The net.ipv4.ip_forward flag is used to tell the server whether it can forward packets or not. If the server is not to be used as a router, set the flag to 0. Setting the flag to 0 ensures that a server 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 net.ipv4.ip_forward parameter to 0 in /etc/sysctl.conf- net.ipv4.ip_forward=0 Modify active kernel parameters to match- # /sbin/sysctl -w net.ipv4.ip_forward=0# /sbin/sysctl -w net.ipv4.route.flush=1

See Also

https://workbench.cisecurity.org/files/85

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(12), CSCv6|9.2

Plugin: Unix

Control ID: d2bcb0773e320db9afdc23394669e279954d4162980b08170a58c7aa78df4b6d