Users Guide

NOTE: To verify the currently congured 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 congure and view an interface as a DHCP client to receive an IP address, use the following commands.
1 Enter INTERFACE Conguration mode on an Ethernet interface.
CONFIGURATION mode
interface type slot/port
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
congured as a DHCP client.
3 Manually acquire a new IP address from the DHCP server by releasing a dynamically acquired IP address while retaining the DHCP
client conguration on the interface.
EXEC Privilege mode
release dhcp interface type slot/port
4 Acquire a new IP address with renewed lease time from a DHCP server.
EXEC Privilege mode
renew dhcp interface type slot/port
To display DHCP client information, use the following show commands in EXEC Privilege mode.
• To display statistics about DHCP client interfaces, use the show ip dhcp client statistics interface type slot/
port
command.
• To clear DHCP client statistics on a specied or on all interfaces, use the clear ip dhcp client statistics {all |
interface
type slot/port} command.
• To display dynamic IP address lease information currently assigned to a DHCP client interface, use the show ip dhcp lease
[interface
type slot/port] command.
• To display log messages for all DHCP packets sent and received on DHCP client interfaces, use the debug ip dhcp client
packets [interface
type slot/port command.
• To display log message on DHCP client interfaces for IP address acquisition, IP address release, IP address and lease time renewal, and
release an IP address, use the [no] debug ip dhcp client events [interface type slot/port] command.
DHCP Client on a Management Interface
These conditions apply when you enable a management interface to operate as a DHCP client.
• The management default route is added with the gateway as the router IP address received in the DHCP ACK packet. It is required to
send and receive trac to and from other subnets on the external network. The route is added irrespective when the DHCP client and
server are in the same or dierent subnets. The management default route is deleted if the management IP address is released like
other DHCP client management routes.
• ip route for 0.0.0.0 takes precedence if it is present or added later.
• Management routes added by a DHCP client display with Route Source as DHCP in the show ip management route and show
ip management-route dynamic command output.
• Management routes added by DHCP are automatically reinstalled if you congure a static IP route with the ip route command that
replaces a management route added by the DHCP client. If you remove the statically congured IP route using the no ip route
command, the management route is reinstalled. Manually delete management routes added by the DHCP client.
• To reinstall management routes added by the DHCP client that is removed or replaced by the same statically congured management
routes, release the DHCP IP address and renew it on the management interface.
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Dynamic Host Conguration Protocol (DHCP)