I have an ethernet over power adapter somewhere in a cupboard from perhaps 10 years ago.
Back then it was standard for the admin password to be 'admin'. They'd often even print it on the device itself.
Yes but aren't you supposed to change that one? The problem with the rzadmin is that it will continue to work even after you change the regular admin one...
I have a small Tenda 5-port gigabit dumb switch. It uses the same switch chip as this TP-Link, just with different branding; even the "SG105" model number is the same:
https://goughlui.com/2022/02/27/unbox-teardown-tp-link-tl-sg...