# $NetBSD: host-npf.conf,v 1.11.8.1 2023/11/05 17:38:24 martin Exp $ # # Simple ruleset for a host with (i.e., not routing) two interfaces, # ethernet and wifi. # # DHCP (v4 and v6), SLAAC, ICMPv6, ICMP echo requests, traceroute, mDNS traffic # are permitted, inbound, on either interface. # # SSH to the host is allowed in via the ethernet interface. # blacklistd(8) is used to prevent SSH bruteforce attempts. # # No specific rules for the wifi interface. # # All traffic from the host is permitted, outbound, on either interface. # $wired_if = "wm0" $wifi_if = "iwn0" $wired_addrs= ifaddrs($wired_if) $wifi_addrs = ifaddrs($wifi_if) alg "icmp" procedure "log" { # Send log events to npflog0, see npfd(8) log: npflog0 } group "wired" on $wired_if { # Placeholder for blacklistd (configuration separate) to add blocked hosts ruleset "blacklistd" # Allow SSH on wired interface and log all connection attempts pass stateful in on $wired_if proto tcp to $wired_addrs port ssh apply "log" } group "wifi" on $wifi_if { } group default { # Default deny, otherwise last matching rule wins block all apply "log" # Don't block loopback pass on lo0 all # Allow incoming DHCP server responses pass in family inet4 proto udp from any port bootps to any port bootpc pass in family inet6 proto udp from any to any port "dhcpv6-client" # Allow IPv6 ICMP pass family inet6 proto ipv6-icmp all # Allow incoming IPv4 pings pass in family inet4 proto icmp icmp-type echo all # Allow being tracerouted pass in proto udp to any port 33434-33600 # Allow incoming mDNS traffic from neighbours pass in proto udp to any port mdns # Allow all outbound traffic pass stateful out all }