and save the dynamically acquired IP address, use the shutdown command on the interface. To display
the dynamic IP address and show DHCP as the mode of IP address assignment, use the show
interface type slot/port[/subport] command. To unconfigure the IP address, use the no
shutdown command when the lease timer for the dynamic IP address is expired. The interface acquires a
new dynamic IP address from the DHCP server.
To configure a secondary (backup) IP address on an interface, use the ip address command at the
INTERFACE configuration level.
Use the no ip address dhcp command to:
• Release the IP address dynamically acquired from a DHCP server from the interface.
• Disable the DHCP client on the interface so it cannot acquire a dynamic IP address from a DHCP
server.
• Stop DHCP packet transactions on the interface.
When you enter the release dhcp command, the IP address dynamically acquired from a DHCP server
is released from an interface. The ability to acquire a new DHCP server-assigned address remains in the
running configuration for the interface. To acquire a new IP address, use the renew DHCP command in
EXEC Privilege mode or the ip address dhcp command in INTERFACE Configuration mode.
To manually configure a static IP address on an interface, use the ip address command. A prompt
displays to release an existing dynamically acquired IP address. If you confirm, the ability to receive a
DHCP server-assigned IP address is removed.
To enable acquiring a dynamic IP address from a DHCP server on an interface configured with a static IP
address, use the ip address dhcp command. A prompt displays to confirm the IP address
reconfiguration. If you confirm, the statically configured IP address is released. An error message displays
if you enter the release dhcp or renew dhcp commands.
To renew the lease time of the dynamically acquired IP, use the renew dhcp command on an interface
already configured with a dynamic IP address.
NOTE: To verify the currently configured dynamic IP address on an interface, use the show ip
dhcp lease command. The show running-configuration command output only displays ip
address dhcp. The currently assigned dynamic IP address does not display.
To configure and view an interface as a DHCP client to receive an IP address, use the following
commands.
1. Enter INTERFACE Configuration mode on an Ethernet interface.
CONFIGURATION mode
interface type slot/port[/subport]
2. Acquire the IP address for an Ethernet interface from a DHCP network server.
INTERFACE mode
ip address dhcp
Dynamically assigned IP addresses can be released without removing the DHCP client operation on
the interface on a switch configured as a DHCP client.
Dynamic Host Configuration Protocol (DHCP) 305