STIGQter 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 send Internet Control Message Protocol (ICMP) redirects.

DISA Rule

SV-257968r1155748_rule

Vulnerability Number

V-257968

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RHEL-09-253065

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure RHEL 9 to not allow interfaces to perform IPv4 ICMP redirects.

Create a configuration file if it does not already exist:

$ sudo vi /etc/sysctl.d/ipv4_send_redirects.conf

Add the following line to the file:
net.ipv4.conf.all.send_redirects = 0

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

$ sudo sysctl --system

Check Contents

Verify RHEL 9 does not IPv4 ICMP redirect messages.

Check the value of the "all send_redirects" variables with the following command:

$ sudo sysctl net.ipv4.conf.all.send_redirects
net.ipv4.conf.all.send_redirects = 0

If "net.ipv4.conf.all.send_redirects" is not set to "0" and is not documented with the information system security officer (ISSO) as an operational requirement or is missing, this is a finding.

Vulnerability Number

V-257968

Documentable

False

Rule Version

RHEL-09-253065

Severity Override Guidance

Verify RHEL 9 does not IPv4 ICMP redirect messages.

Check the value of the "all send_redirects" variables with the following command:

$ sudo sysctl net.ipv4.conf.all.send_redirects
net.ipv4.conf.all.send_redirects = 0

If "net.ipv4.conf.all.send_redirects" is not set to "0" and is not documented with the information system security officer (ISSO) as an operational requirement or is missing, this is a finding.

Check Content Reference

M

Target Key

5551