ZTP: Phone-home client

You can use either the legacy DHCP-options-based ZTP or the phone-home client (PHC) to provision software for the switch. If the switch boots up and there are DHCP options received from DHCP server for ZTP, ZTP resumes. If DHCP options are not present, PHC is attempted. PHC enables the switch to securely obtain bootstrapping data, such as a configuration or software image, with no user intervention other than having to physically connect the switch to the network. When the switch first boots, PHC connects to a redirect server, which will redirect to a phone home server to get the configuration or software image. To initiate either DHCP-options-based ZTP or PCH, the switch must either be in a factory default state, or you can issue the request system zeroize command.