OPNsense DHCP Configuration#

What Was Established#

Procedures for modifying DHCPv4 ranges and identifying other network segments where IP assignment ranges must be managed to prevent conflicts.

Key Decisions#

• DHCP Scope Management: Always ensure static leases or reserved IPs (like Proxmox) are excluded from the dynamic DHCP range to prevent IP conflicts.
• Subnet Alignment: DHCP ranges must reside within the defined subnet (e.g., /24 for 192.168.0.0/24).

Current Configuration#

DHCPv4 Modification#

1. Navigate to Services → DHCPv4 → [Interface].
2. Under General DHCP Options, set the Range (Start and End IP).
3. Save and Apply.

Other Assignment Areas to Monitor#

• DHCPv6: Found under Services → DHCPv6 → [Interface].
• VPNs:
  • OpenVPN: VPN → Open/IPsec → [Server] (Tunnel Network).
  • WireGuard: Manual assignment per peer.
• VLANs: Each VLAN interface requires its own DHCP scope.

Historical Notes#

As of March 2025, this covers the standard DHCPv4/v6 setup for the LAN and VLAN interfaces.