Port knocking is used to stop port scan by the attackers who seeks the vulnerable services to attack. Here is guide for the HP Helion Public Cloud Users to use Port Knocking in Ubuntu 14.04 LTS or equivalent Deb Linux. HP Helion Public Cloud has Private Key (.pem) based login system to the instances. Also on HP Cloud, we need to configure the router, subnet, Ingress-Egress Policies to properly SSH … [Read more...]