Which of the following usually incorporates an 8-digit code that can be found on the bottom of a SOHO router?

Port forwarding maps an external port to an internal IP and port for inbound traffic and involves no PIN or hardware identifier.

WPS was designed to simplify wireless network setup by providing an 8-digit PIN method as an alternative to entering a lengthy WPA2 passphrase. This PIN is printed on a sticker on the bottom or back of most SOHO routers and is used to authenticate devices during the WPS enrollment process. The PIN method is the defining characteristic that makes WPS identifiable on router hardware.

Wireless encryption such as WPA2 uses a passphrase or pre-shared key configured by the administrator, not a fixed 8-digit code printed on the device.

Port triggering opens inbound ports dynamically in response to outbound traffic and does not involve any PIN or device-specific code.