/ip firewall filter

# Блокируем всех из чёрного списка
add action=drop chain=input comment="Drop blocklist" dst-address-list=blocklist
add action=drop chain=forward comment="Drop blocklist" dst-address-list=blocklist

# Фильтруем полезный ICMP
add chain=icmp protocol=icmp icmp-options=0:0 action=accept comment="ICMP echo reply"
add chain=icmp protocol=icmp icmp-options=3:0 action=accept comment="ICMP net unreachable"
add chain=icmp protocol=icmp icmp-options=3:1 action=accept comment="ICMP host unreachable"
add chain=icmp protocol=icmp icmp-options=3:4 action=accept comment="ICMP host unreachable fragmentation required"
add chain=icmp protocol=icmp icmp-options=4:0 action=accept comment="ICMP allow source quench"
add chain=icmp protocol=icmp icmp-options=8:0 action=accept comment="ICMP allow echo request"
add chain=icmp protocol=icmp icmp-options=11:0 action=accept comment="ICMP allow time exceed"
add chain=icmp protocol=icmp icmp-options=12:0 action=accept comment="ICMP allow parameter bad"
add chain=icmp action=drop comment="ICMP deny all other types"

# Блокируем Bogon
add action=drop chain=forward comment="Block Bogon IP Address" src-address=127.0.0.0/8
add action=drop chain=forward dst-address=127.0.0.0/8
add action=drop chain=forward src-address=224.0.0.0/3
add action=drop chain=forward dst-address=224.0.0.0/3

# Блокируем DNS запросы на внешний интерфейс
add action=drop chain=input comment="Drop DNS" dst-port=53 in-interface=WAN protocol=udp
add action=drop chain=input dst-port=53 in-interface=WAN protocol=tcp

# Блокируем взлом Windows
# https://support.microsoft.com/ru-ru/kb/826955
add action=drop chain=input comment="Block hole Windows" dst-port=135,137-139,445,593,4444 protocol=tcp
add action=drop chain=forward dst-port=135,137-139,445,593,4444 protocol=tcp
add action=drop chain=input dst-port=135,137-139 protocol=udp
add action=drop chain=forward dst-port=135,137-139 protocol=udp

# Защита от брутфорса SSH
add action=drop chain=input comment="drop ssh brute forcers" dst-port=22
    protocol=tcp src-address-list=ssh_blacklist
add action=add-src-to-address-list address-list=ssh_blacklist
    address-list-timeout=3d chain=input connection-state=new dst-port=22
    protocol=tcp src-address-list=ssh_stage3
add action=add-src-to-address-list address-list=ssh_stage3 address-list-timeout=
    30m chain=input connection-state=new dst-port=22 protocol=tcp
    src-address-list=ssh_stage2
add action=add-src-to-address-list address-list=ssh_stage2 address-list-timeout=
    30m chain=input connection-state=new dst-port=22 protocol=tcp
    src-address-list=ssh_stage1
add action=add-src-to-address-list address-list=ssh_stage1 address-list-timeout=
    30m chain=input connection-state=new dst-port=22 protocol=tcp

# Защита от сканера портов
add chain=input protocol=tcp psd=21,3s,3,1 action=add-src-to-address-list address-list=port_scanners address-list-timeout=2w comment="Port scanners to list" disabled=no
# Комбинации TCP флагов, указывающих на использование сканера портов
add chain=input protocol=tcp tcp-flags=fin,!syn,!rst,!psh,!ack,!urg action=add-src-to-address-list address-list=port_scanners address-list-timeout=2w comment="NMAP FIN Stealth scan"
add chain=input protocol=tcp tcp-flags=fin,syn action=add-src-to-address-list address-list=port_scanners address-list-timeout=2w comment="SYN/FIN scan"
add chain=input protocol=tcp tcp-flags=syn,rst action=add-src-to-address-list address-list=port_scanners address-list-timeout=2w comment="SYN/RST scan"
add chain=input protocol=tcp tcp-flags=fin,psh,urg,!syn,!rst,!ack action=add-src-to-address-list address-list=port_scanners address-list-timeout=2w comment="FIN/PSH/URG scan"
add chain=input protocol=tcp tcp-flags=fin,syn,rst,psh,ack,urg action=add-src-to-address-list address-list=port_scanners address-list-timeout=2w comment="ALL/ALL scan"
add chain=input protocol=tcp tcp-flags=!fin,!syn,!rst,!psh,!ack,!urg action=add-src-to-address-list address-list=port_scanners address-list-timeout=2w comment="NMAP NULL scan"
# Запрет подключений сканеров портов
add chain=input src-address-list=port_scanners action=drop comment="dropping port scanners" disabled=no
add chain=forward src-address-list=port_scanners action=drop comment="dropping port scanners" disabled=no

# Разрешаем уже установленные подключения и связанные
add chain=input connection-state=established action=accept comment="Allow Established connections"
add chain=input connection-state=related action=accept comment="Allow Related connections"

# Разрешаем внешние подключения для собственных нужд
add action=accept chain=input dst-port=22 in-interface=WAN protocol=tcp comment="Allow SSH"
add action=accept chain=input dst-port=80 in-interface=WAN protocol=tcp comment="Allow HTTP"
add action=accept chain=input dst-port=161 in-interface=WAN protocol=udp comment="Allow SNMP"
add action=accept chain=input dst-port=443 in-interface=WAN protocol=tcp comment="Allow HTTPS"
add action=accept chain=input dst-port=1194 in-interface=WAN protocol=tcp comment="Allow OpenVPN"
add action=accept chain=input dst-port=1194 in-interface=WAN protocol=udp
add chain=input comment="Allow L2TP" dst-port=1701 in-interface=WAN protocol=tcp
add chain=input comment="Allow L2TP" dst-port=1701 in-interface=WAN protocol=udp
add chain=input comment="Allow PPTP" dst-port=1723 in-interface=WAN protocol=tcp
add chain=input comment="Allow GRE" in-interface=WAN protocol=gre

# Запрет всех входящих на маршрутизатор
add chain=input in-interface=WAN action=drop comment="Drop everything else"

# Разрешаем уже установленные подключения и связанные
add chain=forward connection-state=established action=accept comment="Allow Established connections"
add chain=forward connection-state=related action=accept comment="Allow Related connections"

# Запрет транзита '''битых''' и '''неправильных''' пакетов
add chain=forward connection-state=invalid action=drop comment="Drop Invalid connections"

# Заперт установки новых транзитных входящих соединений на WAN порту
add action=drop chain=forward comment="Drop new forward WAN" connection-state=new in-interface=WAN

/ip firewall filter
add action=accept state=related,established chain=input
add action=drop chain=input