Technical Tip: Reserving a DHCP IP address for a particular MAC address (IP/MAC binding)

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Description	This article describes option for a DHCP IP address reservation to a particular MAC address, remote-ID or circuit-ID
Scope	All FortiGate units in NAT mode
Solution	FortiGate unit can be configure the to assign specific IP addresses to a computer, based on its:  MAC address remote-id (received on option82 from DHCP relay) circuit-id (received on option82 from DHCP relay) The DHCP server always assigns the reserved IP address to the client. The number of reserved addresses that can be define ranges from 10 to 200 depending on the FortiGate model. From the GUI: Go to the Network Menu -> Interfaces -> portX (where the DHCP is configured) -> Advanced -> IP Address Assignments Rules. GUI From the CLI: config system dhcp server     edit 1         config reserved-address             edit 1                 set type mac (default)                 set ip 10.136.0.150                 set mac 00:01:00:01:00:01 (client MAC address)             next             edit 2                 set type option82                 set ip 10.136.0.151                 set remote-id "Client-Number-string"             next             edit 3                 set type option82                 set ip 10.136.0.152                 set circuit-id "Circuit-Number-string"             next         end      next end Note: An IP address bound to a MAC address must be in the range of IP addresses (start-ip to end-ip) from an existing DHCP server already configured on the FortiGate.  For more details about DHCP configuration, see the FortiGate CLI reference or the related articles below. Related articles: Technical Tip: Using DHCP server 'options' on a FortiGate Technical Tip: Diagnosing DHCP on a FortiGate