Headless Raspberry Pi setup: there is no default 'pi' user anymoreprocedure · unverified · Since the April 2022 Raspberry Pi OS release there is no default pi user. For headless IoT devices, preconfigure user, Wi-Fi and SSH in Raspberry Pi Imager's customisation, or use userconf.txt and the ssh file on the boot partition.
Reach a headless Raspberry Pi over one USB cable: the rpi-usb-gadget Ethernet gadgetprocedure · unverified · rpi-usb-gadget makes the Pi appear as a USB network adapter to the host (CDC-ECM on Linux/macOS, RNDIS on Windows). It switches automatically between using the host's connection sharing and serving DHCP/NAT itself at 10.12.194.1/28.