Users Guide

Congure the System to be a DHCP Client
A DHCP client is a network device that requests an IP address and conguration 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 conguration is not received. Use bare
metal provisioning (BMP) to receive conguration parameters (Dell Networking OS version and a conguration le). 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 Conguring 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 congured by default as a DHCP client to acquire a
dynamic IP address from a DHCP server.
• By default, the switch is congured to operate in Jumpstart mode as a DHCP client that sends DHCP requests to a DHCP server
to retrieve conguration information (IP address, boot-image lename, and conguration le). All ports and management
interfaces are brought up in Layer 3 mode and pre-congured with no shutdown and no ip address. For this reason, you
cannot enter conguration commands to set up the switch. To interrupt a Jumpstart process, prevent a loop from occurring, and
apply the FTOS image and startup conguration stored in the local ash, enter the stop jump-start command from the console.
To recongure the switch so that it boots up in normal mode using the FTOS image and startup conguration le in local ash,
enter the reload-type normal-reload command and save it to the startup conguration:
FTOS# reload-type normal-reload
FTOS# write memory
FTOS# reload
• To re-enable Jumpstart mode for the next reload, enter the reload-type jump-start command.
DHCP Client Operation with Other Features
The DHCP client operates with other Dell Networking OS features, as the following describes.
Stacking
The DHCP client daemon runs only on the master unit and handles all DHCP packet transactions. It periodically synchronizes the
lease le with the standby unit.
When a stack failover occurs, the new master requires the same DHCP server-assigned IP address on DHCP client interfaces. The
new master reinitiates a DHCP packet transaction by sending a DHCP discovery packet on nonbound interfaces.
Virtual Link Trunking (VLT)
A DHCP client is not supported on VLT interfaces.
VLAN and Port Channels
DHCP client conguration and behavior are the same on Virtual LAN (VLAN) and port-channel (LAG) interfaces as on a physical
interface.
DHCP Snooping
A DHCP client can run on a switch simultaneously with the DHCP snooping feature as follows:
• If you enable DHCP snooping globally on a switch and you enable a DHCP client on an interface, the trust port, source MAC
address, and snooping table validations are not performed on the interface by DHCP snooping for packets destined to the DHCP
client daemon.
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Dynamic Host Conguration Protocol (DHCP)