Your router MUST already have a static IP Address for your main ISP connection. Usually the block of additional addresses will be numbered quite differently from your base IP Address

Note: The first and last IP Addresses in the block are un-usable. Thus if you lease a block of 8 IP addresses only the middle 6 are available to be used. For example if your ISP specifies the IP address block of 210.243.151.176/29, the list of allocated IP addresses is:

210.243.151.176      –         Subnet Address
210.243.151.177
210.243.151.178
210.243.151.179
210.243.151.180
210.243.151.181
210.243.151.182
210.243.151.183        –       Broadcast Address

The following steps will show you how to configure your Vigor router to enter two of the IP addresses

a)    Add 210.243.151.179, 210.243.151.180 into IP Alias of Internet Access.

 

b) We could view these IP addresses on NAT Setup/DMZ or Open Ports.

If you can get a range of public IPs via PPPoA/PPPoE or MPoA, you can enable 2nd subnet to let PCs with public IP to access internet behind Vigor router. Please set one of the public IPs and their subnet mask as below. Then you can set one of the static public IP to a PC on LAN.