Mikrotik Script: Webserver behind NAT

gistfile1.txt

/ip firewall 
dst-nat protocol=tcp dst-port=80 Action dst-nat to-address=20.20.20.45 to-ports=80

add action=dst-nat chain=dstnat comment="" disabled=no dst-port=80 protocol=tcp to-addresses=20.20.20.45 to-ports=80

#Creating pppoe interface and ADSL internet connection

/ interface pppoe-client 
add name="pppoe-out1" max-mtu=1480 max-mru=1480 interface=ether5 \
user="USERNAMEl" password="PASSWORD" profile=default \
service-name="" ac-name="" add-default-route=yes dial-on-demand=no \
use-peer-dns=yes allow=pap,chap,mschap1,mschap2 disabled=no 


#Adding Source NAT for Internet access

/ ip firewall nat 
add chain=srcnat src-address=YOUR NETWORK ADDRESS/MASK action=masquerade comment="" \
disabled=no 

#Adding Destination NAT for WEB server access

/ ip firewall nat 
add chain=dstnat in-interface=pppoe-out1 protocol=tcp dst-port=80 \
action=dst-nat to-addresses=YOUR SERVER ADDRESS to-ports=80 comment="" \
disabled=no 

#Setting mangle for ADSL (works with T-Com...)

/ ip firewall mangle 
add chain=forward protocol=tcp tcp-flags=syn action=change-mss \
new-mss=clamp-to-pmtu comment="ADSL Internet" disabled=no