2х минутное
гугление выдает
мануал и отмотав снизу пару страниц получаем:
Код:

Forgotten the IP Address or Password
If you have forgotten the switch’s IP address or administration password you
can return the switch to its factory default state by doing the following:
1. Remove the power cord from the back of the switch.
2. Remove all cables from the front-panel ports.
3. Connect port 1 to port 2 on the front panel, using a standard network cable.
4. Reconnect the power cord to the rear of the switch.
5. Wait at least 40 seconds before disconnecting port 1 from port 2.
After completing this procedure, there will be no password, the IP address
will be returned to the default 192.168.2.10, and all configuration settings will
be returned to factory defaults.