How to steer a static IP to one external device using a Pace 5031NV.

Internet --> Pace 5031NV --> public web server

Background

My setup is pretty simple. All I needed to do was to route one of my static IP addresses to a single computer. I have no external router to the Pace 5031NV (5031 for short).

I have five public static IP addresses assigned. I want to route one of these to a web server. Once set up to pass through one of the static IPs, the 5031 can act as a firewall and then simply pass anything allowed through the firewall to the target computer without doing any SNAT or DNAT. The computer with the web server gets one of my static IPs but is still protected by the firewall in the 5031. Anything else connected to the 5031 will receive a local address.

In fact my web server is also a gateway to another private subnet, but that's not necessary or important here.

Here's how to set it up

The 5031 has an internal web server to allow setup. Point a browser to its gateway address to access the setup windows. By default it should be 192.168.1.254. YMMV

  1. Ensure that you have your public static subnet address put in the 5031: "Settings|Broadband|Link Configuration|Add Additional Network". Put in the gateway address for the Router address and enter the subnet mask, then enable and save. My public subnet is 162.198.xxx.208/29, so my gateway is 162.198.xxx.214 and my subnet mask is 255.255.255.248. Yours will be different.
  2. Ensure that you are using a private inside subnet: This is the address range that the 5031 will use on your private subnet for attached devices (the ones that do not get the public static IP). "Settings|LAN|DHCP|DHCP Network Range". Choose one of the top two: 192.xxx or 172.xxx. You could specify another one, but be sure it's from the list of non-routeable addresses. If you make changes, save.
  3. Make sure that the computer/device that you want to receive the public address is plugged into the 5031. Set it up for automatic (DHCP) addressing. Make a note of its MAC address. This is the hardware address of the Ethernet adapter.
  4. Assign a static IP to the above computer: "Settings|LAN|IP Address Allocation". This page shows all devices that have been plugged into the 5031 recently. Each has a name "Device:". It will either be a hostname or the word "unknown" followed by the MAC address of the device. Find the one to which you want to assign the public IP  address. Change "Address Assignment" to "Public (select WAN IP Mapping)". Change "WAN IP Mapping" to the public fixed address that you want to use. If you did #1 and #2 above correctly, the drop down list will include all your static addresses. Now save.
  5. Refresh the address of the computer/device that will receive the public static address. The easiest way of doing this is to simply unplug the Ethernet cable connected to the target device, wait a few seconds, and replug.
  6. Open the appropriate holes in the 5031 firewall. "Settings||Firewall|Applications, Pinholes and DMZ". Now choose the name/NIC of the target from the list "Select a computer". Then under "Edit firewall settings for the computer" make the necessary changes. Save when done. Since my device is a web server I opened port 80.
And that is it. All should work. If it doesn't drop me a line. Jim