Concept Guide

Configure the System to be a DHCP Client
A DHCP client is a network device that requests an IP address and configuration parameters from a DHCP server.
Implement the DHCP client functionality as follows:
● The switch can obtain a dynamically assigned IP address from a DHCP server. A start-up configuration is not received. Use
bare metal provisioning (BMP) to receive configuration parameters (Dell EMC Networking OS version and a configuration
file). BMP is enabled as a factory-default setting on a switch.
A switch cannot operate with BMP and as a DHCP client simultaneously. To disable BMP in EXEC mode, use the stop bmp
command. After BMP stops, the switch acts as a DHCP client.
● Acquire a dynamic IP address from a DHCP client is for a limited period or until the client releases the address.
● A DHCP server manages and assigns IP addresses to clients from an address pool stored on the server. For more
information, refer to Configuring the Server for Automatic Address Allocation.
● Dynamically assigned IP addresses are supported on Ethernet, VLAN, and port-channel interfaces.
● The public out-of-band management interface and default VLAN 1 are configured by default as a DHCP client to acquire a
dynamic IP address from a DHCP server.
● By default, the switch is configured to operate in BMP mode as a DHCP client that sends DHCP requests to a DHCP server
to retrieve configuration information (IP address, boot-image filename, and configuration file). All ports and management
interfaces are brought up in Layer 3 mode and pre-configured with no shutdown and no ip address. For this reason,
you cannot enter configuration commands to set up the switch. To interrupt a BMP process, prevent a loop from occurring,
and apply the Dell EMC Networking OS image and startup configuration stored in the local flash, enter the stop bmp
command from the console. To reconfigure the switch so that it boots up in normal mode using the Dell EMC Networking OS
image and startup configuration file in local flash, enter the reload-type normal-reload command and save it to the
startup configuration:
DellEMC# reload-type normal-reload
DellEMC# write memory
DellEMC# reload
● To re-enable BMP mode for the next reload, enter the reload-type jump-start command.
● If the management port is associated with any non-default VRF, then the ip address dhcp command does not work.
Configuring the DHCP Client System
This section describes how to configure and view an interface as a DHCP client to receive an IP address.
Dell EMC Networking OS Behavior: The ip address dhcp command enables DHCP server-assigned dynamic addresses
on an interface. The setting persists after a switch reboot. To stop DHCP transactions 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 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.
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Dynamic Host Configuration Protocol (DHCP)