Read fail2ban's bans as no firewall, and an iptables-nft reject as a refusal, from rulesets captured on a lab machine (hq ADR 0100)

2026-09-22 18:04:48 +02:00
parent 8e2f75454d
commit da65f84c45
5 changed files with 448 additions and 21 deletions
@@ -0,0 +1,22 @@
+-P INPUT ACCEPT
+-P FORWARD DROP
+-P OUTPUT ACCEPT
+-N DOCKER
+-N DOCKER-BRIDGE
+-N DOCKER-CT
+-N DOCKER-FORWARD
+-N DOCKER-INTERNAL
+-N DOCKER-USER
+-N f2b-sshd
+-A INPUT -p tcp -m multiport --dports 22 -j f2b-sshd
+-A FORWARD -j DOCKER-USER
+-A FORWARD -j DOCKER-FORWARD
+-A DOCKER ! -i docker0 -o docker0 -j DROP
+-A DOCKER-BRIDGE -o docker0 -j DOCKER
+-A DOCKER-CT -o docker0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
+-A DOCKER-FORWARD -j DOCKER-CT
+-A DOCKER-FORWARD -j DOCKER-INTERNAL
+-A DOCKER-FORWARD -j DOCKER-BRIDGE
+-A DOCKER-FORWARD -i docker0 -j ACCEPT
+-A f2b-sshd -s 192.0.2.55/32 -j REJECT --reject-with icmp-port-unreachable
+-A f2b-sshd -j RETURN
@@ -0,0 +1,103 @@
+table ip nat {
+	chain DOCKER {
+	}
+
+	chain PREROUTING {
+		type nat hook prerouting priority dstnat; policy accept;
+		xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain OUTPUT {
+		type nat hook output priority dstnat; policy accept;
+		ip daddr != 127.0.0.0/8 xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain POSTROUTING {
+		type nat hook postrouting priority srcnat; policy accept;
+		ip saddr 172.17.0.0/16 oifname != "docker0" counter packets 0 bytes 0 xt target "MASQUERADE"
+	}
+}
+table ip filter {
+	chain DOCKER {
+		iifname != "docker0" oifname "docker0" counter packets 0 bytes 0 drop
+	}
+
+	chain DOCKER-FORWARD {
+		counter packets 0 bytes 0 jump DOCKER-CT
+		counter packets 0 bytes 0 jump DOCKER-INTERNAL
+		counter packets 0 bytes 0 jump DOCKER-BRIDGE
+		iifname "docker0" counter packets 0 bytes 0 accept
+	}
+
+	chain DOCKER-BRIDGE {
+		oifname "docker0" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain DOCKER-CT {
+		oifname "docker0" xt match "conntrack" counter packets 0 bytes 0 accept
+	}
+
+	chain DOCKER-INTERNAL {
+	}
+
+	chain FORWARD {
+		type filter hook forward priority filter; policy drop;
+		counter packets 0 bytes 0 jump DOCKER-USER
+		counter packets 0 bytes 0 jump DOCKER-FORWARD
+	}
+
+	chain DOCKER-USER {
+	}
+
+	chain f2b-sshd {
+		ip saddr 192.0.2.55 counter packets 0 bytes 0 xt target "REJECT"
+		counter packets 0 bytes 0 return
+	}
+
+	chain INPUT {
+		type filter hook input priority filter; policy accept;
+		ip protocol tcp xt match "multiport" counter packets 0 bytes 0 jump f2b-sshd
+	}
+}
+table ip6 nat {
+	chain DOCKER {
+	}
+
+	chain PREROUTING {
+		type nat hook prerouting priority dstnat; policy accept;
+		xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain OUTPUT {
+		type nat hook output priority dstnat; policy accept;
+		ip6 daddr != ::1 xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+}
+table ip6 filter {
+	chain DOCKER {
+	}
+
+	chain DOCKER-FORWARD {
+		counter packets 0 bytes 0 jump DOCKER-CT
+		counter packets 0 bytes 0 jump DOCKER-INTERNAL
+		counter packets 0 bytes 0 jump DOCKER-BRIDGE
+	}
+
+	chain DOCKER-BRIDGE {
+	}
+
+	chain DOCKER-CT {
+	}
+
+	chain DOCKER-INTERNAL {
+	}
+
+	chain FORWARD {
+		type filter hook forward priority filter; policy accept;
+		counter packets 0 bytes 0 jump DOCKER-USER
+		counter packets 0 bytes 0 jump DOCKER-FORWARD
+	}
+
+	chain DOCKER-USER {
+	}
+}
@@ -0,0 +1,105 @@
+table ip nat {
+	chain DOCKER {
+	}
+
+	chain PREROUTING {
+		type nat hook prerouting priority dstnat; policy accept;
+		xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain OUTPUT {
+		type nat hook output priority dstnat; policy accept;
+		ip daddr != 127.0.0.0/8 xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain POSTROUTING {
+		type nat hook postrouting priority srcnat; policy accept;
+		ip saddr 172.17.0.0/16 oifname != "docker0" counter packets 0 bytes 0 xt target "MASQUERADE"
+	}
+}
+table ip filter {
+	chain DOCKER {
+		iifname != "docker0" oifname "docker0" counter packets 0 bytes 0 drop
+	}
+
+	chain DOCKER-FORWARD {
+		counter packets 0 bytes 0 jump DOCKER-CT
+		counter packets 0 bytes 0 jump DOCKER-INTERNAL
+		counter packets 0 bytes 0 jump DOCKER-BRIDGE
+		iifname "docker0" counter packets 0 bytes 0 accept
+	}
+
+	chain DOCKER-BRIDGE {
+		oifname "docker0" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain DOCKER-CT {
+		oifname "docker0" xt match "conntrack" counter packets 0 bytes 0 accept
+	}
+
+	chain DOCKER-INTERNAL {
+	}
+
+	chain FORWARD {
+		type filter hook forward priority filter; policy drop;
+		counter packets 0 bytes 0 jump DOCKER-USER
+		counter packets 0 bytes 0 jump DOCKER-FORWARD
+	}
+
+	chain DOCKER-USER {
+	}
+}
+table ip6 nat {
+	chain DOCKER {
+	}
+
+	chain PREROUTING {
+		type nat hook prerouting priority dstnat; policy accept;
+		xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain OUTPUT {
+		type nat hook output priority dstnat; policy accept;
+		ip6 daddr != ::1 xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+}
+table ip6 filter {
+	chain DOCKER {
+	}
+
+	chain DOCKER-FORWARD {
+		counter packets 0 bytes 0 jump DOCKER-CT
+		counter packets 0 bytes 0 jump DOCKER-INTERNAL
+		counter packets 0 bytes 0 jump DOCKER-BRIDGE
+	}
+
+	chain DOCKER-BRIDGE {
+	}
+
+	chain DOCKER-CT {
+	}
+
+	chain DOCKER-INTERNAL {
+	}
+
+	chain FORWARD {
+		type filter hook forward priority filter; policy accept;
+		counter packets 0 bytes 0 jump DOCKER-USER
+		counter packets 0 bytes 0 jump DOCKER-FORWARD
+	}
+
+	chain DOCKER-USER {
+	}
+}
+table inet f2b-table {
+	set addr-set-sshd {
+		type ipv4_addr
+		flags interval
+		elements = { 192.0.2.55 }
+	}
+
+	chain f2b-chain {
+		type filter hook input priority filter - 1; policy accept;
+		tcp dport 22 ip saddr @addr-set-sshd reject with icmp port-unreachable
+	}
+}