I have a customer who is rolling out new web-based software that requires we open LPR printing (port 515) from a printer on the LAN to the WAN. All connections looking for WAN:515 should go to LAN:515.

My WAN IP is: 71.6.55.226
The LAN IP of printer is: 10.0.0.10

I didn't set up this Mikrotik originally, but the WAN interface is called "RED", and the LAN interface is called "GREEN". There are already a few ports for Small Business Server 2003 opened up, and I tried to mimic those settings to get everything to work, to no avail. I have also been through a bunch of other port forwarding and NAT posts here on the forums, trying all suggestions with no luck. I don't know if the problem lies with what I'm doing, or if there's something different about LPR printing I don't know about. For the record, I was using TCP as the protocol.

Any help is appreciated, and I promise I won't be hard-headed about trying suggestions.

Well, I can see the packets getting to the router. When I go to "connections", the "TCP State" is "syn sent" with a "U" for "unreplied" instead of "A".