Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.112.1P1 - Page 292

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. 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 file 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 configuration and behavior are the same on Virtual LAN (VLAN) and port-channel (LAG) interfaces as on a physical interface. 292 Dynamic Host Configuration Protocol (DHCP)