- Reset the switch to factory default with
unconfigure switch all
- Enable auto-provision with
This command will take effect the next time the switch reboots, and you'll know that it is active because when you log in the following message will be displayed:
Note: This switch has Auto-Provision enabled to obtain configuration remotely. Commands should be limited to:
Any changes to this configuration will be discarded at the next reboot if auto provisioning sends a ".cfg" file.
(auto-provision) lab10.sw1.1 #
When in this mode the switch will alternately try to obtain an IP address using DHCP from the default vlan and then from the mgmt vlan. When it gets an IP address, it will also expect to receive additional information through DHCP Option 43.
This process will continue indefinitely until one of these things happens:
- The switch receives a DHCP with a valid Option 43
- You disable auto-provision
DHCP is a Vendor-Specific Option code and each vendor is free to decide the information contained in it. Extreme networks uses Option 43 to send the following information to the switch:
- Code 100: TFTP Server IP Address
- Code 101: Config file name (either .cfg or .xsf)
- Code 102: SNMP Trap Server IP Address
When the switch receives this option, it will contact the TFTP server indicated in it and will try to download the configuration file indicated. Once the file is downloaded, the switch will reboot to activate the newly loaded configuration.
- Configure DHCP Option 43 in a Windows DHCP Server.
Since Option 43 is "vendor-dependent", there is a mechanism to select the correct information to send to a device.
When a device that wants to receive Option 43 information sends a DHCP request, it includes a piece of information called Vendor Class Identifier (Option 60).
Extreme switches will use their System-Type
as VCI. The one in the example (Summit-PC) corresponds to the Virtual Switch (EXOS-VM) I usually use in my labs.
To know the System-Type of a given switch, execute show switch
and you will find it.show switch
The DHCP server will look for Option 43 information specific to that VCI and send it with the IP address offer. if it doesn't find a matching VCI, it will send nothing.
In the Windows DHCP Server, you need to define a vendor class for each type of switch (VCI) that you will service.
Open the DHCP Manager. Select your server and right-click on it. Select Define Vendor Classes
from the pop-up menu.
Enter the name of this Vendor Class (I give it the same name as the VCI), enter an optional description, and enter the VCI that you expect to receive from this device (Summit-PC
). Press OK
The new Vendor Class should appear in the list. Press Close
Select your server and right-click on it once more. Select Set Predefined Options...
from the pop-up menu.
In the pop-up window select your newly created Vendor Class.
Define an Option type with a name of tftp-server-address
, a data type of ip address
and a code of 100
. Press OK
Type the IP address of your TFTP server in the Value
Add a second option with a name of config-file-name
, a data type of string
and a code of 101
. Press OK
Type the name of the config file that you want to download to this type of switch. Press OK
to end the process.
You can enable these options globally for all DHCP scopes, or you can enable it for scopes individually. If you don't enable them, they won't be sent...
To enable an option globally, right-click in Server Options
and select Configure Options
In the pop-up window select Advanced
Select the desired Vendor Class
and check each of the options that you want to enable (100
). Press OK
The Server Options
window will now show these options. Note that these options correspond to Vendor Class Summit-PC
We will need to repeat this procedure for each VCI we want to use. Here's an example where I have added a Vendor Class for X460-48p
. In this case, the virtual machine and the X460-48p will receive different configuration files. the DHCP server will decide which is the correct value to send based on the VCI it receives..
If you want to enable these options individually for each scope, the procedure is exactly the same, but you have to perform it on the Scope Options
of the individual scope.
If an option was enabled globally and you re-enable it locally, you can change the option value. So, if the global TFTP server address for all X460-48p points to a server in the central office, you can reprogram the value for the scope of a remote office so it uses a local TFTP server instead of the global one.