RHEL 10 must use reverse path filtering on all Internet Protocol version 4 (IPv4) interfaces.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-281345 | SRG-OS-000420-GPOS-00186 | RHEL-10-800130 | SV-281345r1167185_rule | 2026-03-11 | 1 |
Description
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.
Satisfies: SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00076
ℹ️ Check
Verify RHEL 10 uses reverse path filtering on all IPv4 interfaces.
Check the value of the "net.ipv4.conf.all.rp_filter" variable with the following command:
$ sudo sysctl net.ipv4.conf.all.rp_filter
net.ipv4.conf.all.rp_filter = 1
If "net.ipv4.conf.all.rp_filter" is not set to "1" or is missing, this is a finding.
✔️ Fix
Configure RHEL 10 to use reverse path filtering on all IPv4 interfaces.
Create a configuration file if it does not already exist:
$ sudo vi /etc/sysctl.d/99-ipv4_rp_filter.conf
Add the following line to the file:
net.ipv4.conf.all.rp_filter = 1
Reload settings from all system configuration files with the following command:
$ sudo sysctl --system