"Error: Index of the interface.: DHCP Server enabled on secondary bridged interface - not supported"
When bridging a LAN interface with WAN (X1) interface, we may get an error " Error: Index of the interface.: DHCP Server enabled on secondary bridged interface - not supported". This KB article shows how to get rid of this error message and bridge the LAN interface to WAN interface.
Step 1: Login to the SonicWall Management GUI. Step 2: Navigate to the "Network -> Interfaces" page. Click on the Configure option of the LAN interface which you would like to bridge to WAN interface, for example X0 Interface. Step 3: In the Interface 'X0' Settings window, choose "Mode/IP Assignment "as Layer 2 Bridged Mode and "Bridged to" as X1. Click on OK option.
There is an error message thrown by SonicWall.
Resolution or Workaround:
The bridge interfaces should not have DHCP Lease Scope created on Sonicwall, We need to disable / delete DHCP Lease Scope for that interface on Sonicwall.
Go to Network > DHCP Server, disable the Scope for X0 and click on Accept.
Now, we should be able to bridge LAN to WAN interface and the result will be as follows: