The most commonly used method in DOS Attack attacks is to send ICMP packets to the target system and make the system unable to respond after a while. You can block ICMP Packets on Logsign Server, and drop attacks before they reach you.
1- First of all connect to Logsign via cli.
2- Be root with sudo command.
# sudo bash
3-Add the following line to the sysctl.conf file.
# net.ipv4.icmp_echo_ignore_all = 1 net.ipv4.icmp_echo_ignore_broadcasts = 1
4- Execute following command and exit.
# sysctl -p
After these processes, Logsign will not accept the ICMP Packages that comes.