SD-WAN Router can be configured as a DHCP server, enabling it to provide IP address leases to internal devices connected to its LAN interfaces. If you do not have a standalone DHCP server elsewhere in your network, your SD-WAN Router provides a simple way to handle DHCP addressing.
Configuring DHCP Serving
Setup options are found in Settings > Network > [your internal interface] > DHCP:
The "Enable DHCP Serving" switch turns on DHCP serving for the interface you are editing. DHCP serving is available for use on any LAN or VLAN which has its Config Type set to "Addressed" and is not bridged to another interface.
The options available on this page are:
|Range Start||The first IP address available for DHCP to assign.|
|Range End||The last IP address available for DHCP to assign.|
Both Range Start and Range End must belong to the same address subnet as the interface itself. For example, if your interface has the address 192.168.2.1/24, then your range must also fall within the 192.168.2.0/24 subnet.
|Measured in seconds, this setting determines how long the DHCP lease belongs to the device it is granted to. Once this duration has expired, the device will need to request a new IP lease.|
|Gateway Override||Enables you to specify a gateway address other than the SD-WAN Router.|
|Netmask Override||Enables you to specify a netmask different from the SD-WAN Router's interface address netmask.|
|DNS Override||Enables you to specify a DNS server other than the SD-WAN Router.|
The three override settings are optional. If you do not enter an override, the SD-WAN Router's own internal IP address or netmask will be provided. If you're not sure, it's best to leave these three settings blank.
You can manage DHCP options via the DHCP Options button, which will open a new window listing all current DHCP options. You can add new ones at the bottom of that menu:
|Enabled check-box||Enables & disables the specified DHCP option.|
|Description||A description of the option for your reference.|
The value will list the option number first, then the target server, with no space between.
Managing DHCP Leases & Reservations
You can view current DHCP leases served by the SD-WAN Router and manage DHCP reservations in Settings > Network > DHCP.
Current leases are listed in the bottom half of the page under Leases.
At the top half of the page under Reservations, you'll find a list of all DHCP reservations. These are effectively static IP addresses: whenever a particular device MAC address requests a DHCP lease, it will receive the IP address you specify as a reservation.
You can add reservations in two ways:
- Manually create your leases via the + Add button at the right-hand side. You'll provide a description, the MAC address of the device in question, and the desired IP address.
- You can also convert an existing lease into a reservation by clicking the plus sign icon at the very right-hand side of the Leases list.