I thought I should do a quick post about Mikrotik RouterBoard Hairpin NAT and Port Forwarding. The post in which I used to set this up on my router is found here.
The best explanation for this, would be that if you want to have say http from the public interface forwarded to an internal host, while not impacting LAN access to the RouterBoard’s http port. The forum post linked is how to best handle this situation.
It also allows your internal LAN clients to access your public IP and forward to the appropriate host/service internally too.