[Easy] How to Easily Assign a Global IP Address to Your Home Server or Virtual Machine

This is @ryusei__46 speaking.

In this article, I'd like to share some insights on how to assign global IP addresses to local servers and virtual machines running at home—whether they're Docker containers, Windows WSL environments, or similar setups.

This is particularly useful for scenarios like:

- Making a small website or web application accessible externally

- Setting up a file server that can be accessed from outside your home network

- Using it as a VPN server for your home connection

I believe this method is highly recommended for these purposes.

The approach I'll introduce involves directly connecting to an external network via PPPoE and assigning a fixed global IPv4 address. To implement this method, we'll use Interlink's "ZOOT NEXT" service.

I primarily use this method for assigning global IPs to my home servers. The reason is simple—it requires almost no complex network configuration.

Even when assigning a global IP to the server, convenient command-line tools make it quite straightforward.

Without further ado, let's dive into the explanation.

Prerequisites

Additionally, if you're currently subscribed to "NTT Flette's Hikari" and want to switch to Interlink's "ZOOT NEXT," you'll need to specify your preferred line type during the application process—please verify your options in advance.

One important provider to note is "NURO Light"—since it doesn't utilize NTT's optical fiber network, the methods described here won't be applicable.

That said, even if you're using "NURO Light", Interlink's "MyIP" service remains an option for applications where network bandwidth isn't critical. This service allows you to establish VPN connections to Interlink's servers and obtain fixed global IPv4 addresses. However, note that speed limits are applied—it's only suitable if you're comfortable with these limitations. From my previous experience, the maximum speed appeared to be around 120 Mbps.

Obtaining and subscribing to fixed global IP addresses

First, let's proceed with the fixed global IP address acquisition process from the Interlink "ZOOT NEXT" page.

The page includes a compatibility chart for NTT line types that support this service, so be sure to verify your specific type. There are options available for both NTT East and NTT West.

After verifying, click the "Service Application" button at the bottom of the page. As of my writing, a 2-month free trial is available, so you can easily sign up and cancel immediately if it doesn't meet your needs. Since I started using Interlink around 2021, they've consistently maintained this free trial period, so I don't expect any promotional discounts.

The application button on the Interlink ZOOT NEXT application page

On the next page, you will be prompted to log in with your Interlink member ID. If you're new, please select "No" and proceed with the registration process.

Looks like you're being prompted to log in with your Interlink member ID.

When you proceed, you'll be presented with a service selection screen where you need to enter details for: "Service area," "Flets line type," and "Fixed IP address." Complete these fields before continuing.

Interlink's ZOOT NEXT service selection screen

After completing the payment process on the next page, you'll be shown a confirmation screen where you can finalize your application. Once your application is successfully accepted, you'll see a link to your My Page on the completion page—open it and log in using your registered ID and password.

Now, let's proceed to obtain the authentication credentials for assigning the acquired global IP address. Click "Contract Information Confirmation" in the left menu of your My Page to display your subscribed services, then click "Confirm" to open the "Interlink Membership Registration Notice (Web Version)."

Interlink My Page contract information confirmation screen

When the "Interlink Membership Registration Notification (Web Version)" appears, check the "Information Required for FLET'S Connection" section at the top.

Note down the following details, which will be needed when establishing a PPPoE connection to the server:

- Connection username

- Connection password

- Fixed IP address

Set a fixed global IP address for the server

Now, let's remote-login to the server and execute the following command in the terminal. For this example, we'll configure it on an Ubuntu 22.04 machine.

commandline

 sudo apt-get install -y pppoe pppoeconf

This has installed the packages needed for PPPoE connections.

Before starting PPPoE connection setup

Depending on your router model, you may need to configure either "PPPoE Passthrough" or "PPPoE Bridge" functionality. Without this setup, hosts directly connected to your router won't be able to establish PPPoE connections independently.

The router I'm using is an NTT model called "RS-500KI." This wasn't a custom-selected router—it was provided by NTT when I took service with them.

To verify the configuration settings, open your web browser and access the router's IP address (default gateway) at http://192.168.1.1.

When you first access the settings interface, you'll likely be prompted to register a user ID and password for login—please complete this registration process yourself.

PPPoE configuration screen for NTT's router (RS-500KI)

On the "Advanced Settings" page under the left menu's "Detailed Settings," verify that the "PPPoE Bridge" option is checked in the "Use" field.

To begin configuring PPPoE connections, execute the following command:

commandline

sudo pppoeconf

This command handles everything automatically—from configuring connections to executing the initial connection and even automatic execution on system restart.

PPPoE Configuration Wizard① — Continuing this program will modify the configuration files: /etc/ppp/peers/dsl-provider, /etc/network/interfaces, and /etc/ppp/*-secrets.Proceed with the configuration?

For new settings, "Yes" is appropriate.

PPPoE Configuration Wizard② — Most people using common dial-up providers prefer the "noauth" and "defaultroute" options while removing the "nodetach" option. Should I check my configuration file and modify these settings if necessary?

It seems to automatically check whether any settings need to be changed, so "Yes" should work fine in this case as well.

PPPoE Configuration Wizard③ — Enter the username normally required for PPP login to the provider in the box below. To display the help screen, delete the username and press OK.

Here, enter the "Connection Username" you noted earlier under the "Interlink Membership Registration Notification Web Version."

PPPoE Configuration Wizard④ — Enter the password normally required for PPP login to the provider in the text box below. Note: While entering, you can view the password in plain text.

Here, enter the "connection password" as well.

PPPoE Configuration Wizard⑤ — At least one DNS IP address is required to resolve regular hostnames. Typically, when a connection is established, your provider sends you the addresses of available servers. Should these addresses be automatically added to the nameserver list in your local /etc/resolv.conf file? (Recommended)

Select "Yes" if you want the DNS IP address to be automatically obtained.

PPPoE Configuration Wizard⑥ — Many providers have routers that don't support TCP packets with an MSS greater than 1460. When traversing Ethernet with the default MTU size (1500), outgoing packets will have this MSS. Unfortunately, when forwarding packets from other hosts (i.e., when performing masquerading), the MSS may increase depending on the packet size and the route to the client host. There is a solution: you can limit the maximum MSS using pppoe. For more detailed information about this issue, please refer to the pppoe documentation. (If the above problems still occur, try setting it to 1412 in the dsl-provider file.)

If there are no particular issues, we will proceed with "Yes."

PPPoE Configuration Wizard⑦ — PPPoE has been configured. Do you want to initiate a connection at boot?

Select "Yes" if you want to connect automatically when the system starts.

PPPoE Configuration Wizard⑧ — Now you can start a DSL connection using "pondsl-providertt" and end it with "poff". Do you want to initiate a connection now?

I'd like to start connecting now, so I choose "Yes."

PPPoE Configuration Wizard⑨ — The DSL connection was disconnected. You can use the "plog" command to view its status, and the "ip addr show ppp0" command to view general interface information.

The connection is now complete. You can verify the connection status using the ip addr show ppp0 command.

This will make the server publicly accessible worldwide, so don't forget to configure your firewall settings.

Conclusion

Initially, I was considering subscribing to NTT's FLET'S Hikari fixed IP plan to allocate static IP addresses, but ultimately Interlink proved more cost-effective. More importantly, being able to easily apply for multiple IP assignments and obtain global IP addresses was a significant advantage.

For my specific use case, I installed a VPN server at home to enable remote access to both a file server and web server within my LAN. While my primary web server has since been migrated to Conoha VPS due to reliability concerns, my file server remains managed at my parents' house.

Regarding Interlink's "ZOOT NEXT" service mentioned earlier, since its connection uses PPPoE, transfer speeds can become quite unstable during peak usage periods. Therefore, if you're prioritizing stability, I'd recommend Interlink's "ZOOT NATIVE" (IPv4 over IPv6) instead. However, note that this service requires using a router compatible with "DS-Lite."