Information
This setting prevents the system from accepting ICMP redirects. ICMP redirects tell the
system about alternate routes for sending traffic.
*Rationale*
It is recommended that systems not accept ICMP redirects 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.
Solution
Set the net.ipv6.conf.all.accept_redirects and net.ipv6.conf.default.accept_redirects
parameters to 0 in /etc/sysctl.conf-net.ipv6.conf.all.accept_redirects=0
net.ipv6.conf.default.accept_redirects=0
Modify active kernel parameters to match-
# /sbin/sysctl -w net.ipv6.conf.all.accept_redirects=0
# /sbin/sysctl -w net.ipv6.conf.default.accept_redirects=0
# /sbin/sysctl -w net.ipv6.route.flush=1