In this article, we will show you step by step how to run DHCP Relay configuration on Teltonika Routers.
You will need 2 routers for this configuration. One as DHCP Server and the other as DHCP Relay.
Requirements;
The DHCP Relay device WAN port must be connected to the DHCP server LAN port.
DHCP Relay network settings;
LAN IP/subnet: 192.168.2.1/24 WAN IP: 192.168.4.194 DHCP server network settings; LAN IP/subnet: 192.168.4.1/24
Configuration Steps;
1-Enable the DHCP Relay feature on the device that will transmit DHCP requests. In the WebUI go to Network -> Interface -> LAN -> DHCP Server and Enable
Change the DHCP field value from Enable to Relay and then type the DHCP Server IP address and click Save and Apply.
2. Change the Enable-DHCP-renew firewall rule in Network -> Firewall -> Traffic rules to additionally allow destination port 67.
3. DHCP Server must be able to assign addresses from the 192.168.2.0/24 IP address pool. If the DHCP Server is a Teltonika device running RUTOS, you can add this address pool via the Router's CLI by running the command;
echo "dhcp-range=192.168.2.100,192.168.2.200,12h" >> /etc/dnsmasq.conf 192.168.2.100 - Specifies the beginning of the DHCP address pool range 192.168.2.200 - Indicates the end of the DHCP address pool range 12h - Specifies DHCP lease time
4. In this topology the DHCP Server does not have a route to the DHCP Relay's network so it needs to be added manually. Static routes can be added via Network -> Routing -> Static IPv4 routes.
Interface: DHCP Network interface where Ethernet is located Target: DHCP Relay Network IPv4 netmask: Subnet of DHCP Relay network IPv4 Gateway: IP address of the DHCP relay interface connected to the DHCP Server