RHEL 10 must not accept router advertisements on all Internet Protocol version 6 (IPv6) interfaces.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-281354RHEL-10-800220SV-281354r1167212_ruleCCI-002385medium
Description
An illicit router advertisement message could result in a man-in-the-middle attack. Satisfies: SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00085
STIGDate
Red Hat Enterprise Linux 10 Security Technical Implementation Guide2026-03-11

Details

Check Text (C-281354r1167212_chk)

Note: If IPv6 is disabled on the system, this requirement is not applicable. Verify RHEL 10 does not accept router advertisements on all IPv6 interfaces, unless the system is a router. Check that "net.ipv6.conf.all.accept_ra" is set to not accept router advertisements by using the following command: $ sudo sysctl net.ipv6.conf.all.accept_ra net.ipv6.conf.all.accept_ra = 0 If "net.ipv6.conf.all.accept_ra" is not set to "0" or is missing, this is a finding.

Fix Text (F-85820r1167211_fix)

Configure RHEL 10 to not accept router advertisements on all IPv6 interfaces, unless the system is a router. Create a configuration file if it does not already exist: $ sudo vi /etc/sysctl.d/ipv4_accept_ra.conf Add the following line to the file: net.ipv6.conf.all.accept_ra = 0 Reload settings from all system configuration files with the following command: $ sudo sysctl --system