ZTP operates in the following network environments:
node, file servers, and DHCP server in the same subnet
Figure 1 shows the scenario where all components are in a Layer 2 broadcast domain. There is no DHCP relay and all IP addresses are assigned from a single pool.
Figure 1. Auto-provisioning with all Components in a Layer 2 Broadcast Domain
file servers and DHCP server in the same subnet, separate from the node
Figure 2 shows the scenario, where only the file servers and DHCP server are in the same subnet. DHCP relay is used to fill Option 82 as the gateway address. The gateway address is used to find the appropriate pool in the DHCP server to assign the correct subnet IP address to the system.
Figure 2. Auto-provisioning with all Components in a Layer 2 Broadcast Domain
DHCP allows the Option 3 router to define the default gateway. If multiple addresses are provided using Option 3, the first address is used for the default gateway.
node, file servers, and DHCP server in different subnets
Figure 3 shows the scenario, where all components are in different subnets. DHCP relay adds the Option 82 gateway address to the DHCP request, and the DHCP server adds the Option 3 gateway address of the file server.
Figure 3. Auto-provisioning with all Components in Different Subnets