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V-217296

CAT II (Medium)

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

Rule ID

SV-217296r991589_rule

STIG

SLES 12 Security Technical Implementation Guide

Version

V3R2

CCIs

V-77501

Discussion

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.

Check Content

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

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