5% of IPs Handle Half the World’s Web Requests, Stanford Finds

It is often thought that an IP address is tied to a single device. According to McAfee.com, it is “a unique identifier for devices on a network that enables devices to communicate over the internet.” Websites and other online services use this information to identify users' locations and ensure the correct service is provided. IP addresses are even regarded as personal information, and laws are enacted to prevent the sharing of this data. EU’s GDPR, Canada’s PIPEDA, and California’s CCPA are only some of the laws that observe IP addresses as personal information.

But what if an IP address is not particularly tied to a single device or a person?

A research study conducted at Stanford University has the following findings:

“IP sharing has steadily increased over the past decade, with fewer than 0.2% of domains using a unique IPv4 address and up to millions of domains co-located on single IP addresses. On the client side, traffic is similarly skewed: 5% of client IP addresses account for over half of observed web requests worldwide.”

The numbers are startling: less than 1% of domains worldwide use a unique IPv4 address while more than half of online users worldwide share only 5% of the accounted IP addresses.

IP Address Sharing

IP address sharing is nothing new. IPv4 addresses have run out, and new technologies have been developed to ensure connections between devices continue without compromising their security.

NAT (Network Address Translator) - a networking technology allowing multiple devices to work on a single public IP address while using individual private IP addresses to communicate.

CGNAT (Carrier Grade Network Address Translator) - Used by Internet Service Providers (ISPs) and Mobile Service Companies, these providers assign a single IP address to different devices directly connected to the internet.

VPN and Proxy Servers - A single IP address is assigned to multiple users, and their main role is to prevent websites and other online services from seeing their real IP addresses.

These three technologies help deal with the scarcity of IPv4 addresses while maintaining connectivity and anonymity (for VPN and Proxy Servers). However, the question of individual identity in terms of IP address comes to light.

Technological Implications and a Call to Action

The idea of multiple users with a single public IP address is acceptable for basic geographical detection. Online services use IP addresses to detect location and ensure the correct service is rendered.

However, there are notable effects of a shared public IP address. Cloudflare conducted a study on shared IP addresses and found the following:

 “CGNAT IPs are subject to rate limiting three times more often than non-CGNAT IPs. This is likely because multiple users share the same public IP, increasing the chances that legitimate traffic gets caught by customers’ bot mitigation and firewall rules.”

Basically, users sharing the same IP address on a mobile network experience slower connections because some devices have to go through firewall and bot-prevention mechanisms. A few rogue users will ultimately affect everyone’s internet speed.

The Stanford study concludes with a call to the networking community to examine the purpose of current IP addresses. While it touts itself as a way to identify individual users, technological changes have made location-based identification challenging. Privacy, confidentiality, and identity are important to online users, and the network community plays a large role.