Users Guide

592 DHCP and USB Auto-Configuration
not respond to TFTP Read Requests. If the unicast attempts fail, or if the
DHCP OFFER did not specify a TFTP server address, the auto-configuration
download fails.
If the DHCP server does not specify a host configuration file in DHCP option
67 or download of the host-specific configuration file fails, the Auto
Configuration process makes three attempts to download a network
configuration file with the name dell-net.cfg. The switch unicasts or
broadcasts TFTP requests for a network configuration file in the same
manner as it attempts to download a host-specific configuration file.
The network configuration file consists of a set of IP address-to-hostname
mappings, using the command ip host hostname address. The switch finds its
own IP address, as learned from the DHCP server, in the configuration file
and extracts its hostname from the matching command. If the default
network configuration file does not contain the switch's IP address, the switch
attempts a reverse DNS lookup to resolve its hostname.
A sample dell-net.cfg file might appear as follows:
config
...
ip host switch1 192.168.1.10
ip host switch2 192.168.1.11
... <other hostname definitions>
exit
If a hostname has been identified in the network configuration file or in the
DHCP offer, the switch issues up to three TFTP requests for a host
configuration file named hostname.cfg , where hostname is the first
thirty-two characters of the switch's hostname.
If the switch is unable to map its IP address to a hostname, or no prior host
configuration file has been downloaded, Auto Configuration sends up to
three TFTP requests for the generic host configuration file host.cfg.