hi,

I can login to my ftp server in the office (from home) with the internal ip, when i connect with pptp vpn to the router.
but when i try to login with the public ip it doesn't let me to login.
what is missing?

U must use hairpin nat

http://wiki.mikrotik.com/wiki/Hairpin_NAT

If your RB has a Ip public, you resolve locally the access of FTP. But if your connect outside, you must study how your packet back in IP\Route, maybe back throught the Gateway and not over VPN. In this case, you mangle connection and route over VPN.

hi i tried but doesn't help...