======3.1.1 Ensure IP forwarding is disabled (Scored)======
=====Profile Applicability=====  
<code>
Level 1 - Server
Level 1 - Workstation 
</code>

=====Description=====
The ''net.ipv4.ip_forward'' flag is used to tell the system whether it can forward packets or not.

=====Rationale=====
Setting the flag to 0 ensures that a system with multiple interfaces (for example, a hard proxy), will never be able to forward packets, and therefore, never serve as a router.

=====Audit===== 
Run the following command and verify output matches:
<Code:bash>
# sysctl net.ipv4.ip_forward 
net.ipv4.ip_forward = 0
</Code>

=====Remediation===== 
Set the following parameter in the ''/etc/sysctl.conf'' file:
<Code:bash>
net.ipv4.ip_forward = 0
</Code>
Run the following commands to set the active kernel parameters:
<Code:bash>
# sysctl -w net.ipv4.ip_forward=0 
# sysctl -w net.ipv4.route.flush=1
</Code>