Step I and II are for ROUTERS:
I.You get NAT becouse your router blocks the gunz port and u have to unlock it.
-You can try to PORT FORWARD. [www.portforward.com]<-Choose your router model and game/program what you want to port forward in. ( this is optional)
* This does NOT worked for me.I have a router which isn't needed for port forwarding.
* Portforward.com provides you tips in how to port forward GunZ on every Router Model.
II. Go to your router main page
-depends of the model of router- and disable Firewall/NAT. If you can`t disable.. use DMZ HOST.(This unblocks all of your ports)
* Just a side note: A lot of Router Main Pages is 192.168.1.1.
* I recommend to use DMZ Host. It does not unblock just gunz ports, it opens all your ports.
-How to configure DMZ HOST-
Step 1:
Windows XP:Start>Run>cmd>type:ipconfig
Windows 7:Start>Search "CMD">type:ipconfig
Windows 8:Start>Click on the Little arrow below(It will open APPS)>Windows System(CATEGORY)>Command Prompt>type:ipconfig
Step 2:You will see what IPv4 your router provides,copy/remember it.(My router provides me:192.168.1.107)(Depends on your Router's Model)
Step 3:Go on your router main page(Mine is 192.168.1.1)
Step 4:A box pops-up with username and password fill form.
Usual accounts have the same id and password,admin:
User-admin
Password-admin
Step 5:Go To Forwarding and Open DZM
Step 6:Put the ip that the router gaves you(related to step 1 and 2)
Step 7:Tick enable then press apply. You are finished.
Step 8:Open your GunZ and enjoy!
IV.Disable your Firewall.(Windows/Anti-Virus Firewalls)
-EDIT(ADDED)-
If your connecting to a Router/Wifi, please turn off your router and plugin your modem connection directly to your pc/laptop, NAT may also occur when your connection is too slow to be used by 2 or more people at the same time.
P.S
Sticky please,thank you ;)