how can i hide my server ip

hello guys im newbie to this mikrotik world how can i hide my server IP, i have my ports rb150 and my setup is

port1 = public IP
port2 = 10.2.0.0/16 and my application server ip is >>> 10.2.2.21
port3 = 10.11.0.0/24
port4 = 10.12.0.0/24
port5 = 10.11.0.0/24

if im in port 3 let say my ip is 10.11.0.10 then when i use this command \10.2.2.21\c$ my server shows username and password
it is possible to hide my application server ip???

thanks

iwantlemonjuice

firewall - filter - add - chain = forward - dst-address=10.2.2.21 - action = reject?

thanks chupaka for reply i set a drop rules in 10.2.2.21 and then i add another rules forward and accept specific client Ip only to acces my application server and it works wohoooooo!!!

thanks