DHCP Config

PxeLab's DHCP server supports four operating modes, configurable independently per network interface.

Docs: Architecture | Boot Config | Netboot Catalog

---

Four DHCP Modes

Each network interface (subnet) can independently set the DHCP mode:

Mode	Assigns IP	PXE Options	Non-PXE Clients	Use Case
full	✅	✅	✅ Normal assignment	Sole DHCP server
proxy	❌ yiaddr=0	✅	❌ Ignored	Overlay onto existing DHCP
hybrid	✅	✅ (PXE only)	✅ IP only	Default, best of both
off	❌	❌	❌ Ignored	DHCP disabled

full Mode

PxeLab acts as the sole DHCP server, managing the entire DHCP lifecycle:

Client Discover → PxeLab Offer (IP + Gateway + DNS + PXE Options) → Request → Ack

Use case: New networks, lab environments, isolated networks.

proxy Mode

PxeLab only provides PXE-related options, IP assigned by existing DHCP server:

Client Discover → Existing DHCP Offer (IP) + PxeLab ProxyOffer (PXE options, yiaddr=0)

Key parameters:

• yiaddr=0.0.0.0 — Key indicator for iPXE to identify ProxyDHCP
• Option 60 = "PXEClient" — Required by UEFI PXE Base Code
• siaddr — Points to PxeLab (TFTP/HTTP server address)

Use case: Networks with existing DHCP servers, overlay PXE service.

hybrid Mode (Default)

Smart dual-mode: proxy mode for PXE clients, full mode for others:

PXE clients → proxy mode (yiaddr=0 + PXE options)
Regular clients → full mode (IP assignment + standard options)

Use case: Recommended default for most scenarios.

off Mode

Completely disables DHCP on this interface. Other services (HTTP/TFTP/DNS) are unaffected.

---

Multi-Interface Deployment

Supports multi-NIC, multi-subnet configuration with independent DHCP modes:

# Example: Management + Business interfaces
interfaces:
  - name: eth0          # Management
    ip: 10.0.0.1
    subnets:
      - cidr: 10.0.0.0/24
        dhcp: full       # Self-hosted DHCP
        pool: 10.0.0.100-10.0.0.200

  - name: eth1          # Business
    ip: 192.168.1.100
    subnets:
      - cidr: 192.168.1.0/24
        dhcp: proxy      # PXE overlay, don't interfere with company DHCP

---

IP Reservations

Permanently bind a specific IP to a MAC address, ensuring critical devices always get the same IP:

• Web UI: Service Config → DHCP → Reservations
• API: POST /api/v1/dhcp/reservations
• Conflict detection: Auto-checks if IP is used by other reservations or active leases on create/edit
• Only available for full-mode subnets

---

Access Control (Whitelist/Blacklist)

List	Behavior	Use Case
Whitelist	Only listed MACs can get IPs	Strict device access control
Blacklist	Listed MACs are denied	Block specific devices
Unauthorized	Devices not in any list	Monitoring and auditing

Web UI: Management → Access Control

Config supports pre-import from YAML seed files:

blacklist_seeds:
  - mac: "AA:BB:CC:DD:EE:FF"
    reason: "Decommissioned device"

whitelist_seeds:
  - mac: "11:22:33:44:55:66"
    subnet: "10.0.0.0/24"
    reason: "Server zone"