Factory reset:
Connect ports 1 and 2 with a standard lan cable. Then power on.
Wait.
Wait.
Wait.
Wait.
…
Wait.
Default IP: is printed on your device
Default login: admin + empty password
Hint: Do not forget to save your changes actively via the SAVE button. Otherwise all changes will be lost.
Hint2: It boooooooots veeeeeryyyy sloooooooooooow.
Hint3: You can’t ping? Wait a minute. The switch learns his arp stuff very slowly.