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1.187 RHEL-09-253035

Information

RHEL 9 must use reverse path filtering on all IPv4 interfaces.

GROUP ID: V-257962
RULE ID: SV-257962r991589

Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface on which they were received. It must not be used on systems that are routers for complicated networks, but is helpful for end hosts and routers serving small networks.

Solution

Configure RHEL 9 to use reverse path filtering on all IPv4 interfaces.

Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory:

net.ipv4.conf.all.rp_filter = 1

The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command:

$ sudo sysctl --system

See Also

https://workbench.cisecurity.org/benchmarks/22008

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|II, CCI|CCI-000366, Rule-ID|SV-257962r991589_rule, STIG-ID|RHEL-09-253035, Vuln-ID|V-257962

Plugin: Unix

Control ID: 7895ec892466a3ac1700007b65a000cd6150b5badff792fc108df4469c5d44e7