IP whitelisting best practices

IP whitelisting is a security mechanism that restricts access to networks, systems, or applications based on approved IP addresses(new window). Only IP addresses on the whitelist are permitted to connect, while all others are denied access. This method is typically employed by IT administrators to enhance an organization’s network security by allowing only trusted IP addresses to interact with the organization’s resources.

While this has long been known as IP whitelisting, it’s also referred to as allowlisting, as this is more descriptive and culturally neutral. As we’ll discuss later in this article, Proton VPN for Businesses customers can secure company assets by whitelisting (allowlisting) the IP addresses of dedicated gateway VPN servers that can be accessed by authorized personnel only.

In this article, we’ll look at:

What is an IP address?

An Internet Protocol (IP) address is a computer-friendly numerical label that uniquely identifies every device that connects to the internet (so if you connect to the internet using a WiFi connection, your IP address will be that of the modem/router you’re connecting to over WiFi, rather than your device itself). 

IP addresses work much like postal addresses, allowing data packets to reach their correct destination.  

Learn more about IP addresses(new window)

With regard to IP whitelisting (allowlisting), the first of these functions is most relevant — uniquely identifying an internet connection. IP addresses are usually assigned by your internet service provider(new window) (ISP).

How does IP whitelisting work?

IP whitelisting (allowlisting) is the practice of only allowing specific IP addresses to connect to a company resource, such as a gateway server that controls access to an office local area network (LAN), or an online software as a service (SaaS) platform. All other connections are refused.

It’s the mirror of blacklisting (also known as blocklisting), which allows connections from any IP address that hasn’t been specifically blocked. Examples of how IP whitelisting is used to improve businesses security include:

  • Remote access: Limiting VPN or remote desktop access to specific IP addresses ensures that only known and trusted devices can connect to your company resources.
  • Web applications: Restricting access to administrative interfaces or APIs to a set of known IP addresses helps to prevent unauthorized access.
  • Database servers: Ensuring that only application servers within a specified IP range can connect to the database server reduces the risk of data breaches.
  • Email servers: Allowing email relaying only from specific IP addresses helps to prevent unauthorized use and reduce spam.

Advantages of IP whitelisting

Businesses use IP whitelisting (allowlisting) to improve network and cloud security by restricting access to company resources to only staff members connecting from authorized IP addresses. IP whitelisting offers the following advantages:

Access control

By explicitly defining which IP addresses can connect to a network, server, or application, administrators have precise control over who can access specific resources. This helps ensure that only trusted users or systems have access.

Reduced attack surface

Limiting access to a known set of IP addresses minimizes the number of potential attack vectors. This makes it harder for malicious actors to exploit vulnerabilities, as they first need to bypass the whitelist.

Easy to implement

IP whitelisting is straightforward to implement and configure. Most firewalls, routers, and web servers support IP whitelisting through access control lists(new window) (ACLs) or similar mechanisms.

Improved monitoring and auditing

With IP whitelisting, it becomes easier to monitor and log access attempts. Any access attempt from a non-whitelisted IP can be flagged and investigated, providing valuable data for security audits and incident response.


Many industries are subject to regulatory requirements that mandate strict access controls. IP whitelisting can help organizations comply with such regulations by ensuring that only authorized users can access sensitive data or systems.

Protection against DDoS attacks

IP whitelisting can mitigate the risk of distributed denial-of-service(new window) (DDoS) attacks by allowing only legitimate traffic from whitelisted IPs. This helps to maintain the availability and performance of critical services.

Improved network performance

By restricting access to a limited set of IP addresses, network traffic can be more efficiently managed and filtered, potentially improving overall network performance.


Compared to other security measures, IP whitelisting (allowlisting) is a cost-effective way to add an additional layer of security. It doesn’t require expensive hardware or software and can be managed with existing network infrastructure.


IP whitelisting can be easily scaled to accommodate growing networks. New IP addresses can be added to the whitelist as needed, ensuring that legitimate users continue to have access while maintaining security.

Disadvantages of IP whitelisting

Although it offers some clear security advantages, traditional IP whitelisting (allowlisting) measures do have some potential drawbacks. However, as we’ll discuss below, many of these disadvantages can be overcome using Proton VPN for Business dedicated IP addresses

Maintenance overhead

Maintaining an up-to-date whitelist can be time-consuming and labor-intensive. As users’ IP addresses change (especially if they use dynamic IP addresses), the whitelist must be regularly updated to reflect these changes.

Limited flexibility

IP whitelisting (allowlisting) can be restrictive for users who need to access resources from multiple locations, such as remote workers, mobile users, or employees who travel frequently. Each new location may require an update to the whitelist.


The ability to add IP addresses to the whitelist as needed can be an advantage, but as the number of users or IP addresses that need to be whitelisted grows, managing the whitelist can become cumbersome. This is especially challenging in large organizations with many users and devices.

Difficulty with dynamic IP addresses

Many people, especially those using residential ISPs, have dynamic IP addresses that can change. This necessitates constant updates to the whitelist, which can be impractical and error-prone.

Configuration errors

Manually managing a whitelist increases the risk of configuration errors. Mistakenly excluding a legitimate IP address can prevent your team from accessing necessary resources, while mistakenly including an unauthorized IP address can create security vulnerabilities.

Limited protection

IP whitelisting (allowlisting) only controls access based on IP addresses. It does not protect against threats that originate from whitelisted IPs, such as compromised devices or insider threats. Additional security measures are necessary to address these risks.

Usability challenges

For end-users, IP whitelisting can create usability challenges. Legitimate users might be blocked if their IP address changes or if they attempt to access resources from a non-whitelisted location. This can lead to frustration and hinder productivity.


Users who need to access resources while traveling internationally may face access issues due to IP address changes. Updating the whitelist to include new international IP addresses can be slow and difficult.

Added network complexity

Implementing IP whitelisting can add complexity to network configuration and management. Network administrators must carefully plan and implement whitelisting rules, which can complicate troubleshooting and network design.

False sense of security

Relying solely on IP whitelisting might give a false sense of security. While it does provide an additional layer of defense, it should be part of a broader, multi-layered security strategy that includes firewalls, encryption, authentication, and other security measures.

Proton VPN dedicated IPs

A robust solution to many of the above disadvantages is to lease dedicated gateway servers from Proton VPN. These are VPN gateways that only your authorized staff have access to. You then whitelist (allowlist) only the IP addresses of these gateways, allowing your staff to have secure segmented access to your businesses office LANs, and SaaS, CaaS, PaaS, and IaaS(new window) resources. 

How dedicated IP addressees work

Learn more about private gateways and dedicated IP addresses (new window)

Doing this addresses many (if not all) drawbacks associated with more traditional IP whitelisting approaches.

Easy maintenance and configuration

All your company needs to do is whitelist (allowlist) the IP addresses of any dedicated gateways you have leased from us. This also allows for segmented access to your different resources, as you can whitelist dedicated IPs for some resources, but not others. 

For example, you might manage a company that leases three dedicated IP addresses from Proton VPN. All staff members can use server #1 to access commonly used company resources such as your CRM and collaboration platforms. Only some staff members can use server #2, which provides need-to-know access to specific company resources, and only senior staff members can access server #3, allowing them to see staff management tools and other sensitive resources.

Note that access to dedicated Proton VPN servers is secure anyway, with full support for two-factor authentication(new window) (2FA) via a mobile authenticator app or security key. But whitelisting IPs in this way provides an additional layer of security. 

Proton VPN for Business also supports single sign on(new window) (SSO), making it easy for your staff to securely connect to the company resources they need. 

Security you can trust

Proton VPN is trusted by millions of businesses, journalists, activists, and ordinary people around the world to keep them private and secure on the internet. It’s what we do. We use only the strongest VPN protocols(new window) with their best encryption algorithms(new window) to ensure the connection between your staff members’ devices and our VPN servers can’t be compromised, and continually monitor our bare metal servers with full disk encryption for potential issues. 

Your staff can use 2FA to securely access your dedicated gateways, and our NetShield Ad-blocker(new window) feature can help keep your devices free from becoming compromised by malware. 

Access from anywhere

Because you need only whitelist (allowlist) the IPs of your dedicated VPN gateways, it doesn’t matter if your staff work remotely or are traveling. As long as they are authorized to sign in to your dedicated servers, they’ll be able to access the resources they need from anywhere in the world, and no matter if their own IP address changes.

How to start whitelisting Proton VPN private gateways

By IP whitelisting Proton VPN private gateways, you can grant secure, granular, and segmented control to the SaaS resources used by your business. To get started, you’ll need to:

1. Subscribe to a Proton VPN Professional or Proton VPN Enterprise plan.

2. Purchase and configure one or more dedicated gateways.

3. Whitelist the IP addresses of your private gateways in your SaaS platforms, making it the only way to connect to that resource.

4. Your staff and colleagues can now download our Proton VPN apps and connect to any of your businesses’ private gateways that you’ve authorized them to. 

5. If a gateway has been IP whitelisted in one of your SaaS platforms, any staff member connected to that gateway will be able to access that platform.

Final thoughts: 

IP whitelisting (allowlisting) can be a valuable security tool, but it’s important to be aware of the limitations of traditional IP whitelisting methods, and to implement it only as part of a comprehensive security strategy that addresses a range of potential threats and challenges.

However, IP whitelisting Proton VPN for Business private gateways provides an additional layer of security for your company’s physical and online resources, offering a flexible and modern security solution without the downsides of more traditional IP whitelisting. 

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