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@symm
Created July 29, 2025 21:04
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Proxmox Security Group for hardened DNS
[IPSET trusted_dns]
9.9.9.11
149.112.112.11
[group harden_dns_in]
IN REJECT -p tcp -dport 139 -log nolog # NetBIOS Session
IN REJECT -p udp -dport 137,138 -log nolog # NetBIOS Name & Datagram
IN REJECT -p udp -dport 5355 -log nolog # LLMNR unicast
IN REJECT -p udp -dport 5353 -log nolog # mDNS unicast
IN REJECT -p udp -dport 1900 -log nolog # SSDP unicast
IN REJECT -p tcp -dport 853 -log nolog # DNS over TLS
[group harden_dns_out]
OUT ACCEPT -dest +dc/trusted_dns -p udp -dport 53 -log nolog # Trusted DNS
OUT ACCEPT -dest +dc/trusted_dns -p tcp -dport 53 -log nolog # Trusted DNS TCP
OUT REJECT -p tcp -dport 139 -log nolog # NetBIOS Session
OUT REJECT -p udp -dport 137,138 -log nolog # NetBIOS Name & Datagram
OUT REJECT -p udp -dport 5355 -log nolog # LLMNR unicast
OUT REJECT -p udp -dport 5353 -log nolog # mDNS unicast
OUT REJECT -p udp -dport 1900 -log nolog # SSDP unicast
OUT REJECT -p tcp -dport 853 -log nolog # DNS over TLS
OUT REJECT -p udp -dport 53 -log nolog # Block DNS
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