DHCP Config
Give devices on the network automatic IPs and PXE boot info. Task-oriented steps; protocol details live in DHCP Modes.
Docs: Service Config | DHCP Modes | Boot Menu Config
When to Use
- New network needs automatic IP + boot info → create an interface in
servermode - Network already has DHCP, just want to layer boot capability on top →
proxymode (see Tutorial 2) - A specific device needs a fixed IP → IP reservation
- Debugging "clients can't get an IP" → check the lease tab
Entry: Basic Config → Service Config → DHCP.
Task 1: Create an interface and subnet (server mode)
Click Add Interface in the top-right corner and fill in:
| Field | Meaning |
|---|---|
| Interface name | A name, or pick a detected NIC from the list |
| IP address | The PxeLab server's IP on this subnet |
| Subnet 1 → Subnet CIDR | The network, e.g. 192.168.50.0/24 |
| Subnet 1 → DHCP mode | server (Server DHCP) |
| Subnet 1 → Address pool | "+ Add address range" to set the assignment range |
| Subnet 1 → Gateway / DNS server | Default gateway and DNS for clients (DNS empty = use interface IP) |
| Subnet 1 → Lease time (seconds) | Default 3600 (1 hour) |
Save, then start the DHCP service (port 67) from the service status bar. An interface can hold multiple subnets via "+ Add subnet", each with its own mode and pool.
Task 2: Layer onto existing DHCP (proxy mode)
Create an interface, set the subnet CIDR to your existing network, and pick proxy (Proxy DHCP) as the DHCP mode — leave address pool, gateway, and DNS empty (proxy doesn't assign IPs). Save and start ProxyDHCP (port 4011).
Full flow: Tutorial 2: Layer PXE onto an Existing DHCP Network.
Task 3: IP reservation (fixed IP)
Reservations tab → add a reservation: fill in MAC and IP (hostname and note optional). Reservations take effect when the server-mode DHCP assigns addresses.
- Conflict detection runs automatically: reserved IPs already taken by other reservations or active leases are flagged
- Use for printers, servers, and other devices that need a fixed IP
Task 4: View and manage leases
Leases tab: active leases (IP / MAC / expiry). Supports delete (force release) and batch cleanup.
Task 5: Chain to iPXE
The "Chain to iPXE" toggle in the subnet config: when enabled, PXELinux/GRUB2 clients automatically redirect to load iPXE. Ideal for unifying legacy environments on iPXE (see PXELinux Compatibility & Migration).
Mode Cheat Sheet
| Mode | Assigns IP | Provides boot info | Scenario |
|---|---|---|---|
| server | ✅ | ✅ | PxeLab is the only DHCP (default) |
| proxy | ❌ (existing DHCP assigns) | ✅ | Existing DHCP, add boot |
| off | ❌ | ❌ | No DHCP on this interface |
Protocol details (Option 60, yiaddr=0, etc.): DHCP Modes.