Network Access Translation

NAT is the practice of using private IP addresses inside of one network connected to the Internet and having a routing gateway forwarding requests to public IP addresses.

For Sony PlayStation networking, they differentiate between NAT Types 1 (open), 2, 3 and 4 (closed).

Microsoft says there are three types of NAT: Open, Moderate and Strict.

The detection of Nintendo Switch is considered to following behavior1:

  • Type A: Mapping: "Endpoint-Independent", Filtering: "Endpoint-Independent" or "Address-Dependent Filtering"
  • Type B: Mapping: "Endpoint-Independent", Filtering: "Address and Port-Dependent"
  • Type C: Mapping: the others, but the source port is predictable.
  • Type D: In other cases.
  • Type F: Failed to receive UDP packets.

A means it's directly connected to the internet, B means UPnP is enabled, C means some ports are blocked and D means you have Carrier-Grade NAT or a completely firewalled network.

Nintendo actually recommends opening 1-65536/udp to the Switch2, which is effectively putting the Switch into an UDP DMZ. It might also use UPnP.


see also: IPv6

  • Last modified: 2024-07-05 14:31