Dell PowerConnect 8100 User's Configuration Guide - Page 345

Obtaining the Configuration File If the DHCP OFFER identifies a configuration file, either as option 67 or in the file field of the DHCP header, the switch attempts to download the configuration file. NOTE: The configuration file is required to have a file type of *.cfg. The TFTP client makes three unicast requests. If the unicast attempts fail, or if the DHCP OFFER did not specify a TFTP server address, the TFTP client makes three broadcast requests. If the DHCP server does not specify a configuration file or download of the configuration file fails, the Auto Configuration process attempts to download a 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 default network configuration file consists of a set of IP address-tohostname 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 follows: config ... ip host switch1 192.168.1.10 ip host switch2 192.168.1.11 ... exit Once a hostname has been determined, the switch issues a TFTP request for a 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, Auto Configuration sends TFTP requests for the default configuration file host.cfg. Auto Image and Configuration Update 345