Firewall
How to disable ICMP timestamp responses in Linux
Iptables rule to disable ICMP timestamp responses in Linux. Block ICMP timestamp request (13) and ICMP timestamp reply (14). Verify using hping3 or nping
How to configure remote port forwarding (openssh & firewall)
How to configure remote port forwarding to bypass firewall openssh. The tunnel is initiated from server-host back to the client. Port forwarding using firewalld …