A common way to carry out a DoS attack is to flood the target system with ICMP packets until it stops responding. You can configure the Logsign server to ignore ICMP echo (ping) requests so that these packets are dropped by the kernel.
1- First of all connect to Logsign via cli.
2- Be root with sudo command.
sudo bash3- Add the following lines to the /etc/sysctl.conf file. Each setting must be on its own line and must not start with #, otherwise it is treated as a comment.
net.ipv4.icmp_echo_ignore_all = 1
net.ipv4.icmp_echo_ignore_broadcasts = 14- Execute following command and exit.
sysctl -pAfter these steps, the Logsign server no longer replies to ICMP echo (ping) requests. Ping-based availability checks against the server (for example from a monitoring tool) will also report it as down. Logsign updates do not remove these lines, because the installer only appends its own settings to /etc/sysctl.conf when they are missing. To undo the change, delete the two lines and run sysctl -p again.