Hairpin NAT on Mikrotik

Scenario

• LAN: 192.168.0.0/24

• WAN Public IP: 100.100.100.100

• Server on LAN listen on port: TCP 4443

Create Address for LAN subnet

/ip address 
print
add address=192.168.0.0/24 list=LAN
add address=100.100.100.100 list=WAN

Mark Connection for Hairpin NAT

/ip firewall
print
chain=prerouting action=mark-connection new-connection-mark=Hairpin NAT passthrough=yes src-address-list=LAN dst-address-list=WAN

Perform Hairpin NAT

/ip firewall nat
print
chain=srcnat action=masquerade connection-mark=Hairpin NAT

Configure Port Forwarding

/ip firewall nat
print
chain=dstnat action=dst-nat to-addresses=192.168.0.100 to-ports=4443 protocol=tcp dst-address-list=WAN dst-port=443

Reference

• https://forum.mikrotik.com/viewtopic.php?t=172380