Information
An attacker could use a compromised host to send invalid ICMP redirects to other router devices in an attempt to corrupt routing and have users access a system set up by the attacker as opposed to a valid system.
Solution
Set the following parameters in the /etc/sysctl.conf file - net.ipv4.conf.all.send_redirects = 0 net.ipv4.conf.default.send_redirects = 0 Run the following commands to set the active kernel parameters - # sysctl -w net.ipv4.conf.all.send_redirects=0
# sysctl -w net.ipv4.conf.default.send_redirects=0
# sysctl -w net.ipv4.route.flush=1