3.6.1 TCP/IP Tuning - ipsrcrouteforward

Information

The ipsrcrouteforward parameter determines whether or not the system forwards IPV4 source-routed packets.

The ipsrcrouteforward will be set to 0, to prevent source-routed packets being forwarded by the system. This would prevent a hacker from using source-routed packets to bridge an external facing server to an internal LAN, possibly even through a firewall.

Solution

In /etc/tunables/nextboot, add the ipsrcrouteforward entry-

no -p -o ipsrcrouteforward=0

This makes the change permanent by adding the entry into /etc/tunables/nextboot.

See Also

https://workbench.cisecurity.org/files/528