Dhcp Autoconfiguration; Dhcp Server Configuration Guidelines - Cisco IE-4000 Software Configuration Manual

Performing Switch Setup Configuration
Information About Performing Switch Setup Configuration

DHCP Autoconfiguration

DHCP autoconfiguration downloads a configuration file to one or more switches in your network from a DHCP server. The
downloaded configuration file becomes the running configuration of the switch. It does not over write the bootup
configuration saved in the flash, until you reload the switch.
DHCP Auto-Image Update
You can use DHCP auto-image upgrade with DHCP autoconfiguration to download both a configuration and a new image
to one or more switches in your network. The switch (or switches) downloading the new configuration and the new image
can be blank (or only have a default factory configuration loaded).
If the new configuration is downloaded to a switch that already has a configuration, the downloaded configuration is
appended to the configuration file stored on the switch. (Any existing configuration is not overwritten by the downloaded
one.)
Note: To enable a DHCP auto-image update on the switch, the TFTP server where the image and configuration files are
located must be configured with the correct option 67 (the configuration filename), option 66 (the DHCP server
hostname) option 150 (the TFTP server address), and option 125 (description of the file) settings.
For procedures to configure the switch as a DHCP server, see
"Configuring DHCP" section of the "IP addressing and Services" section of the Cisco IOS IP DHCP Configuration Guide,
Release 15.0.
After you install the switch in your network, the auto-image update feature starts. The downloaded configuration file is
saved in the running configuration of the switch, and the new image is downloaded and installed on the switch. When
you reboot the switch, the configuration is stored in the saved configuration on the switch.

DHCP Server Configuration Guidelines

Follow these guidelines if you are configuring a device as a DHCP server:

Configure the DHCP server with reserved leases that are bound to each switch by the switch hardware address.

If you want the switch to receive IP address information, you must configure the DHCP server with these lease
options:
— IP address of the client (required)
— Subnet mask of the client (required)
— Router IP address (default gateway address to be used by the switch) (required)
— DNS server IP address (optional)

If you want the switch to receive the configuration file from a TFTP server, you must configure the DHCP server with
these lease options:
— TFTP server name (required)
— Boot filename (the name of the configuration file that the client needs) (recommended)
— Hostname (optional)

Depending on the settings of the DHCP server, the switch can receive IP address information, the configuration file,
or both.

If you do not configure the DHCP server with the lease options described previously, it replies to client requests with
only those parameters that are configured.
DHCP Server Configuration Guidelines, page 64
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