The SUSE operating system must not be performing Internet Protocol version 4 (IPv4) packet forwarding unless the system is a router.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-217296	SLES-12-030430	SV-217296r646767_rule		Medium

Description
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this software is used when not required, system network information may be unnecessarily transmitted across the network.

STIG	Date
SLES 12 Security Technical Implementation Guide	2022-09-13

Details

Check Text ( C-18524r646765_chk )
Verify the SUSE operating system is not performing IPv4packet forwarding, unless the system is a router. Check to see if IPv4 forwarding is enabled using the following command: > sysctl net.ipv4.ip_forward net.ipv4.ip_forward = 0 If the network parameter "ipv4.ip_forward" is not equal to "0" or nothing is returned, this is a finding.

Fix Text (F-18522r646766_fix)
Configure the SUSE operating system to not performing IPv4 packet forwarding by running the following command as an administrator: > sudo sysctl -w net.ipv4.ip_forward=0 If "0" is not the system's default value, add or update the following line in "/etc/sysctl.d/99-stig.conf": > sudo sh -c 'echo "net.ipv4.ip_forward=0" >> /etc/sysctl.d/99-stig.conf' > sudo sysctl --system