Cisco SD-WAN Device License
If you want to onboard Cisco vEdge routers for your SD-WAN lab running 20.x or later, you'll need device licenses.
You'll need a Cisco Smart Account to generate these. After generating the device license, you can download a serialFile.viptela file. You can upload this file directly to the Cisco SD-WAN vManage controller.
This file is compressed and when uncompressed, contains three files:
cisco_cert.cerviptela_serial_fileviptela_serial_file.sig
The viptela_serial_file is in JSON format and contains the actual device licenses. Probably when you upload the serialFile.viptela file to the controller, it uses the viptela_serial_file.sig file which contains a signature to ensure that the viptela_serial_file was not tampered with.