3.3.1 Ensure IPv6 router advertisements are not accepted (Scored)

Level 1 - Server
Level 1 - Workstation 

This setting disables the system's ability to accept IPv6 router advertisements.

It is recommended that systems not accept router advertisements as they could be tricked into routing traffic to compromised machines. Setting hard routes within the system (usually a single default route to a trusted router) protects the system from bad routes.

Run the following command and verify output matches:

# sysctl net.ipv6.conf.all.accept_ra 
net.ipv6.conf.all.accept_ra = 0 
# sysctl net.ipv6.conf.default.accept_ra 
net.ipv6.conf.default.accept_ra = 0

Set the following parameter in the /etc/sysctl.conf file:

net.ipv6.conf.all.accept_ra = 0 
net.ipv6.conf.default.accept_ra = 0

Run the following commands to set the active kernel parameters:

# sysctl -w net.ipv6.conf.all.accept_ra=0 
# sysctl -w net.ipv6.conf.default.accept_ra=0 
# sysctl -w net.ipv6.route.flush=1