Use a Public IP on LAN using 'For Routing Usage' option

If our ISP allocates a block public IP addresses for us, then we may use the public IP address with IP Routed Subnet or Routing Usage LAN. This article describes how to use a public iP address with Routing Usage LAN.

Suppose ISP provides a public IP subnet 211.100.200.152/255.255.255.252 for us, and the gateway IP is 211.100.200.158. The public IP addresses we can use are between 211.100.200.153 to 211.100.200.154. The following shows how to set up a non-NAT subnet so that the server behind Vigor Router can use the public IP address 211.100.200.154.

WAN Setup

Go to WAN >> Internet Access and configure the WAN connection according to what ISP provides. (Note: If it is necessary to specify an IP address manually, remember that subnet mask for WAN interface should be larger than that of LAN interface.)

LAN Setup

1. Go to LAN >> VLAN,

• Enable VLAN Configuration
• Set up a VLAN for LAN2 Subnet
• Specify the LAN ports that belongs to LAN2 subnet (which is port 5 and 6 in this example), note that these are the ports to which the host should connect

2. Go to LAN >> General Setup, click on Details Page for LAN 2.

3. Set up TCP/IP details for LAN 2, 

1. Enable LAN2
2. Select For Routing Usage
3. Enter the IP Address for the router. Note that this could be the same as router's WAN IP
4. Enter the Subnet Mask according to ISP.

4. For DHCP Server Configuration, we may either:

• Disable DHCP Server, and manually set a fixed IP/Subnet Mask on the host
• Enable DHCP Server, and set up the DHCP IP pool according to IP range which the ISP provides

After finishing the above configurations, PC or Server that connects to Port 5 or Port 6 with IP settings as IP 211.100.200.154/ mask 255.255.255.252/ Gateway IP 211.100.200.153 will be able to access Internet through Vigor Router.