Allied Telesis AT-S39 - Manual (Page 36)

Section II: Local and Telnet Management
36
Caution
Do not include spaces or special characters, such as asterisks (*) or
exclamation points (!), in a password. This is particularly important if
you will be managing the switch from a web browser, because most
web browsers cannot handle special characters in passwords.
L - Release DHCP IP Address
If you activate DHCP on the switch so that the unit obtains its IP
address from a DHCP server on your network, you can use this
selection prior to resetting or powering off the switch so that the
IP address is released back to the DHCP server for assignment to
another network device. This option only appears when the DHCP
option has been activated on the switch.
3. After you have set the parameters, type S to select Save Configuration
Changes.
Note
A change to the IP address, subnet mask, or gateway address will
not take effect until after you reset the switch. You can reset the
device using selection 9 - Reset Switch in the Administration Menu
or with the Reset button on the back panel of the unit.