Im trying to change nat type 3 to nat type 2 on my smc router for my playstation 3? Whats the best way to go about that. thanks

On most store bought routers you can only set NAT on or off. If you turn it off and it is your gateway router (entry point to the internet basically) then you must have NAT on. What issue are you trying to solve?

Nat 3 means that your PS3 is having problems accessing the internet connection. The best way to resolve this is to not play online using wifi just connect your PS3 directly into your router via an Ethernet cable.If this doesn't work call your internet provider and they will be more than glad to fix your problem.

is this an issue with CoD or PS3? if it is then try this link.
http://boardsus.playstation.com/t5/PlayStation-Network/How-to-change-Nat-Type-3-to-Nat-Type-2/td-p/42580697

I’m happy to help further over the phone at https://www.6ya.com/expert/thomas_b83e841f114394f4

To reduce the NAT

1 ) Disable the firewall in the router

2) Enable the Playstation in the DMZ

3) Make sure UPnP is Enabled

You will have to open the following ports in your modem /router
Make sure the firewall is disabled in the Modem /Router
Make sure that UPnP is Enabled

Playstation Network Required Ports

TCP 80
TCP 443
TCP 5223
UDP 3478
UDP 3479
UDP 3658

Playstation Online Game Ports

Call of Duty 3:

UDP 3074
TCP 3074

MotorStorm

UDP 3659
UDP 3660

You can use http://whatsmyip.org/ports/ to test if the ports are open.

To reduce the NAT

1 ) Disable the firewall in the router

2) Enable the Playstation in the DMZ

3) Make sure UPnP is Enabled

I had the same Problem with a Linksys WRT54G router had to get different router to fix it for me

I had the same Problem with a Linksys WRT54G router had to get different router to fix it for me

Playstation Guides ( PS3 ) to change from NAT3 to NAT2...
Guide1 or Guide2 or Guide3

to enable your upnp you need to "log into your router" the all your settings will be there for you to change such as enable upnp tutorials for this can be found on youtube