Comtrend Corporation NexusLink 3120 User Manual page 54

Select Enable DHCP Server Relay (not available if NAT enabled), and enter the
DHCP Server IP Address. This allows the Router to relay the DHCP packets to the
remote DHCP server. The remote DHCP server will provide the IP address.
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2 LAN INTERFACE
To configure a secondary IP address, tick the checkbox  outlined (in RED) below.
IP Address: Enter the secondary IP address for the LAN port.
Subnet Mask: Enter the secondary subnet mask for the LAN port.
Ethernet Media Type:
Configure auto negotiation, or enforce selected speed and duplex mode for the
Ethernet ports.
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