{ networking.nftables.enable = true; # fules for the networking.nftables.ruleset = '' # Check out https://wiki.nftables.org/ for better documentation. # Table for both IPv4 and IPv6. table inet filter { # Block all incomming connections traffic except SSH and "ping". chain input { type filter hook input priority 0; # accept any localhost traffic iifname lo accept # accept traffic originated from us ct state {established, related} accept # ICMP # routers may also want: mld-listener-query, nd-router-solicit ip6 nexthdr icmpv6 icmpv6 type { destination-unreachable, packet-too-big, time-exceeded, parameter-problem, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert } accept ip protocol icmp icmp type { destination-unreachable, router-advertisement, time-exceeded, parameter-problem } accept # allow "ping" ip6 nexthdr icmpv6 icmpv6 type echo-request accept ip protocol icmp icmp type echo-request accept # accept SSH connections (required for a server) tcp dport 22 accept # tcp dport 21 accept # count and drop any other traffic counter drop } # Allow all outgoing connections. chain output { type filter hook output priority 0; accept } chain forward { type filter hook forward priority 0; accept } } ''; }