First you have to create all scope options from your primary DHCP server to the backup/failover dhcp server. If you try to run failover without setting up custom options then you will get Error 20010. The specified option does not exist.
|Active Directory DHCP Error 20010. The specified option does not exist|
|Replicate DHCP Scope options from the primary DHCP server to the backup. Must be done by hand.|
|Define Vendor Classes...|
Display Name - "Mitel IP Phone Options"
Description: Mitel Specific Options for IP phone provisioning
in the ASCII type without quotes
in the binary add 00 after the 6D. If you don't you'll have problems because the phone is looking for that null value.
|Create Mitel IP Phone Class|
|Set Mitel Predefined options|
In "Option class", drop down "Mitel IP Phone Options"
|"Option class", drop down "Mitel IP Phone Options"|
For name, enter "Mitel Phone Config"
For data type, choose String
For Code, enter 43
|Mitel Predefined Options and Values|
Click [OK] to commit
You can now add the Mitel Scope Options to the scope by going to "scope options" right click select "Configure Scope Options" then go to advanced and select the vendor class we created called "Mitel Phone Options" and make sure it is checked and add your Mitel Configuration String.
|Mitel Scope Options|
Now in this instance I had an issue with the reconcile database but if you didn't have a failover dhcp server before you should be good to go. Below I go over how to fix the an issue with the DHCP database where it is not reconciling properly.
Fixing the Reconcile DatabaseThe Primary DHCP server was still trying to reconsile to the old failover DHCP server, as shown below.
|Reconcile DHCP Database|
|DHCP Reconcile IP|
To fix this (because our scope won't properly reconcile) we need to use netsh.
go to the netsh prompt by typing "netsh" without quotes then press enter.
|netsh list command|
netsh> dhcp server scope $youripscope delete lease $ipaddress
|netsh delete cmd|
Once verified you can go to your DHCP server and reconcile your DHCP and you should get a message "The database is consistent"
|Error is removed database reads on consistent.|