Service Manual

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.
3. Manually acquire a new IP address from the DHCP server by releasing a dynamically acquired IP
address while retaining the DHCP client configuration on the interface.
EXEC Privilege mode
release dhcp interface type slot/port[/subport]
4. Acquire a new IP address with renewed lease time from a DHCP server.
EXEC Privilege mode
renew dhcp interface type slot/port[/subport]
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[subport] command.
• To clear DHCP client statistics on a specified or on all interfaces, use the clear ip dhcp client
statistics {all | interface type slot/port[/subport]} 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[/subport]] 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[/subport] 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[/subport]] 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 traffic 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 different
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 configure a static IP route
with the ip route command that replaces a management route added by the DHCP client. If you
remove the statically configured 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 configured management routes, release the DHCP IP address and renew it on the
management interface.
• Management routes added by the DHCP client have higher precedence over the same statically
configured management route. Static routes are not removed from the running configuration if a
dynamically acquired management route added by the DHCP client overwrites a static management
route.
• Management routes added by the DHCP client are not added to the running configuration.
332
Dynamic Host Configuration Protocol (DHCP)