STIGQter: STIG Summary: Red Hat Enterprise Linux 9 Security Technical Implementation Guide Version: 2 Release: 9 Benchmark Date: 01 Jul 2026:

RHEL 9 must not respond to Internet Control Message Protocol (ICMP) echoes sent to a broadcast address.

DISA Rule

SV-257966r1155742_rule

Vulnerability Number

V-257966

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RHEL-09-253055

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

Weight

10

Fix Recommendation

Configure RHEL 9 to ignore IPv4 ICMP echoes sent to a broadcast address.

Create a configuration file if it does not already exist:

$ sudo vi /etc/sysctl.d/ipv4_icmp_echo_ignore_broadcasts.conf

Add the following line to the file:
net.ipv4.icmp_echo_ignore_broadcasts = 1

Reload settings from all system configuration files with the following command:

$ sudo sysctl --system

Check Contents

Verify RHEL 9 ignores ICMP echoes sent to a broadcast address.

Check the value of the "icmp_echo_ignore_broadcasts" variable with the following command:

$ sudo sysctl net.ipv4.icmp_echo_ignore_broadcasts
net.ipv4.icmp_echo_ignore_broadcasts = 1

If "net.ipv4.icmp_echo_ignore_broadcasts" is not set to "1" or is missing, this is a finding.

Vulnerability Number

V-257966

Documentable

False

Rule Version

RHEL-09-253055

Severity Override Guidance

Verify RHEL 9 ignores ICMP echoes sent to a broadcast address.

Check the value of the "icmp_echo_ignore_broadcasts" variable with the following command:

$ sudo sysctl net.ipv4.icmp_echo_ignore_broadcasts
net.ipv4.icmp_echo_ignore_broadcasts = 1

If "net.ipv4.icmp_echo_ignore_broadcasts" is not set to "1" or is missing, this is a finding.

Check Content Reference

M

Target Key

5551