Cisco Catalyst 2960 Series, Configuration Manual

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• Unless you configure a timeout, the DHCP-based autoconfiguration with a saved configuration feature
tries indefinitely to download an IP address.
• The auto-install process stops if a configuration file cannot be downloaded or if the configuration file
is corrupted.
• The configuration file that is downloaded from TFTP is merged with the existing configuration in the
running configuration but is not saved in the NVRAM unless you enter the
write memory or
copy running-configuration startup-configuration
privileged EXEC command. If the downloaded
configuration is saved to the startup configuration, the feature is not triggered during subsequent system
restarts.
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.)
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 Cisco IOS image
file) settings.
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:
• You should 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)
◦ DNS server IP address (optional)
◦ Router IP address (default gateway address to be used by the switch) (required)
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
1563
Information About Performing Switch Setup Configuration