I use a belkin router. Its quite simple. Forward the needed ports 7000 7100 7200, once you done that change all of your IPs to your network IP.
Go into the DBServer and load up !serverinfo.txt it will look somthing like this
127.0.0.1 127.0.0.1 7200
change the second ip address with your online IP (example
127.0.0.1 tevo.no-ip.org 7200 ) save and close that.
Now go into your Login Server and load up !addrtable.txt it should look somthing like this
Foundation Foundation 127.0.0.1 127.0.0.1 127.0.0.1:7100
change the second and third ips with your online IP (example
Foundation Foundation 127.0.0.1 tevo.no-ip.org tevo.no-ip.org:7100 ) save and close that.
Now go into your mir200 folder and load up !runaddr.txt it should look like this
127.0.0.1
change it to the your online IP (example
tevo.no-ip.org ) save and close that.
tevo.no-ip.org - that IP is just an example, most of this information I took from Sentures thread so goes to him for most of it.