IP Whitelisting

What is IP Whitelisting?

IP whitelisting, also called an IP whitelist or IP allowlisting, is a security method that only allows access to a system, network, or API from a pre-approved list of IP addresses. Any request coming from an IP address not on that list is blocked automatically.

Businesses commonly use IP whitelisting to restrict access to admin panels, internal tools, and APIs, including messaging APIs like an SMS API or fax API. Alongside security measures such as TLS, IP whitelisting can add another layer of protection by restricting where requests can originate.

How to Whitelist IP Address Access

Setting up an IP whitelist generally follows the same steps regardless of the system:

• Choose which IP addresses to allow: Identify the IP addresses used by trusted users, office networks, servers, or other systems that need access.

• Add them to the whitelist: Enter the approved IP addresses in the platform or system's security settings.

• Block other IP addresses: Configure the system so that requests from IP addresses not on the approved list are denied.

• Test the whitelist: Check that approved IP addresses can connect and unapproved addresses are blocked.

• Keep the list updated: Add or remove IP addresses whenever your network or access requirements change.

• IP whitelisting works best with static IP addresses, which stay the same over time. Dynamic IP addresses can change, which may cause an approved user or system to lose access.

Why Use IP Whitelisting?

IP whitelisting adds a layer of protection anywhere sensitive data or system access needs to be limited to known locations, including:

• Reduces the attack surface: Only known, trusted IP addresses can reach the system, which cuts down opportunistic access attempts significantly.

• Adds a layer beyond passwords: Stolen credentials alone aren't enough to gain access if the request comes from an unapproved location.

• Simple to set up: A whitelist is usually quicker to configure than more complex access control systems, especially for a small, stable list of IPs.

• Clear audit trail: Blocked and allowed requests can be logged by IP, making it easier to spot unusual access attempts.

IP Whitelisting vs IP Allowlisting

These terms describe the same thing. Allowlisting is the more current term and is used increasingly in security documentation and vendor guidance, while whitelisting remains the more commonly searched term. Both refer to the same list based access control method.

Real World Use Cases of IP Whitelisting