Nftables Firewall Basis Konfiguration

Die Basis Konfiguration

• Die Basiskonfiguration besagt das von der Firewall nach aussen alles erlaubt ist.
• Auf die Firewall aber normal nur von innen zugegriffen werden darf.

#!/usr/sbin/nft -f
flush ruleset
define local_tcp_ports = { 22 }
define save_interfaces = { enp0s8, enp0s9, enp0s10 }

table inet filter {
       chain input {
               type filter hook input priority filter; policy drop;
               ct state established,related accept
               ct state new iif "lo" accept
               ct state new tcp dport $local_tcp_ports accept
       }

       chain forward {
               type filter hook forward priority filter; policy drop;
                 ct state established,related accept
       }
       chain output {
               type filter hook output priority filter; policy drop;
               ct state established,related accept
               ct state new accept
       }

}