Dell S4048T-ON, Configuration Manual

Page: 302 / 1146

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 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 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 Networking OS image and startup configuration file in local flash, enter the
reload-type
normal-reload
command and save it to the startup configuration:
Dell# reload-type normal-reload
Dell# write memory
Dell# 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 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 [ /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.
302 Dynamic Host Configuration Protocol (DHCP)