define icmp_protos = {ipv6-icmp, icmp, igmp} table arp filter { limit lim_arp { rate over 50 mbytes/second burst 50 mbytes } chain input { type filter hook input priority filter policy accept limit name lim_arp counter drop counter } chain output { type filter hook output priority filter policy accept limit name lim_arp counter drop counter } } table inet filter { limit lim_reject { rate over 1000/second burst 1000 packets } limit lim_icmp { rate over 50 mbytes/second burst 50 mbytes } chain forward { type filter hook forward priority filter policy drop ct state invalid log level debug prefix "drop invalid forward: " counter drop iifname lo counter accept limit name lim_reject log level debug prefix "drop forward: " counter drop log level debug prefix "reject forward: " counter meta l4proto tcp ct state new counter reject with tcp reset ct state new counter reject counter } chain input { type filter hook input priority filter policy drop ct state invalid log level debug prefix "drop invalid input: " counter drop iifname lo counter accept iif != lo ip daddr 127.0.0.1/8 counter reject iif != lo ip6 daddr ::1/128 counter reject meta l4proto $icmp_protos limit name lim_icmp counter drop meta l4proto $icmp_protos counter accept tcp dport 22 counter accept udp dport 60000-61000 counter accept ct state {established, related} counter accept limit name lim_reject log level debug prefix "drop input: " counter drop log level debug prefix "reject input: " counter meta l4proto tcp ct state new counter reject with tcp reset ct state new counter reject counter } chain output { type filter hook output priority filter policy accept oifname lo counter accept meta l4proto $icmp_protos limit name lim_icmp counter drop meta l4proto $icmp_protos counter accept counter } }