The general framework for this DHCP option is set out in RFC 2132 (Option 60). This
information is used to convey configuration settings or other identification
information about a client, but the specific string to use should be supplied by your
service provider or network administrator. Options 60 (vendor-class-identifier), 66
(tftp-server-name) and 67 (bootfile-name) statements can be added to the server
daemon's configuration file as described in the following section.
If the DHCP server has an index entry for a switch requesting service, it should reply
with the TFTP server name and boot file name. Note that the vendor class identifier
can be formatted in either text or hexadecimal, but the format used by both the
client and server must be the same.
Information passed on to the switch from a DHCP server may also include a
configuration file to be downloaded and the TFTP servers where that file can be
accessed. If the Factory Default Configuration file is used to provision the switch at
Referenced by a
startup, in addition to requesting IP configuration settings from the DHCP server, it
will also ask for the name of a bootup configuration file and TFTP servers where
that file is stored.
If the switch receives information that allows it to download the remote bootup file,
it will save this file to a local buffer, and then restart the provision process.
Note the following DHCP client behavior:
Configuring Automatic Installation of Operation Code and Configuration Settings
Console(config)#interface vlan 2
Console(config-if)#ip dhcp client class-id hex 0000e8666572
The bootup configuration file received from a TFTP server is stored on the
switch with the original file name. If this file name already exists in the switch,
the file is overwritten.
If the name of the bootup configuration file is the same as the Factory Default
Configuration file, the download procedure will be terminated, and the switch
will not send any further DHCP client requests.
If the switch fails to download the bootup configuration file based on
information passed by the DHCP server, it will not send any further DHCP client
If the switch does not receive a DHCP response prior to completing the bootup
process, it will continue to send a DHCP client request once a minute. These
requests will only be terminated if the switch's address is manually configured,
but will resume if the address mode is set back to DHCP.
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| Initial Switch Configuration