How Long Does an IP Address Stay Attached to a Home or Business?

IP Config ImageOne of the most common questions we get from resellers and customers is - don’t IP addresses change?  If so how can you target digital ads at households using an IP address?  To fully understand the nature of IP address assignment, you need to know a little more about DHCP or Dynamic Host Configuration Protocol.  DHCP is a client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other related configuration information such as the subnet mask and default gateway (Source Microsoft TechNet).  Or put more simply DHCP is the process your Internet Service Provider (ISP) uses to assign an IP Address to your home or business.

Static vs. Dynamic IPs

Your ISP can either configure your IP address to be static (it stays the same) or dynamic (it can change). Most purchasers of business class internet have static IP addresses assigned to them since servers and a number of business applications or Virtual Private Networks (VPNs) typically require the same IP address every day in order to operate properly. In fact most business once they reach a certain size will have IP addresses directly assigned to them from ARIN (American Registry of Internet Numbers, which is the governing body for IP address assignment in the United States), instead of their ISP. These IP address assignments can total hundreds or even millions of IP’s for large businesses.  Most residential customers have a dynamic IP address, meaning that it can change. These IP addresses are assigned by your ISP via the basic process outlined below.   When your router receives a non-static DHCP assigned IP address from your ISP there is a pre-defined time limit built into the assignment, this time limit is called a DHCP Lease. The typical lease time for ISP’s in the United States is roughly 7 days. However in most instances your router will renegotiate this lease prior to its expiration. During the lease renegotiation, it is very common for the same IP to be reassigned to your router. In fact our research has discovered many homes that have theoretically dynamic IP’s, but have held the same IP for multiple years. Because of this recursive reassignment the typical location targeted by El Toro has held the same IP address for 7 months.

What is my IP Address?

Just in case all of this was not confusing enough… there are actually TWO different types of IP addresses in most homes and offices.

  1. There is a public IP, sometimes referred as a gateway IP. The gateway is the IP address assigned by your ISP and it actually resides on your router or firewall.  This is the only IP address which is seen by the world.
  2. Additionally, your router will assign an internal IP address to each connected device on your Local Area Network (LAN). These devices “behind” your router/firewall need an IP to communicate with each other, as well as communicate to the router so they can connect to the internet. Even though you have many devices on your LAN, they often all share the same public IP address

Often times, people do not know what their public IP is, as you do not see it on your device.  If you want to find what your current external IP address is, you can go to  The IP on your local device behind the router is a private IP address, and isn't necessary to share, as no one can use it unless they are directly on your LAN

How Does El Toro Use This Information

The El Toro system is based on observations of multiple data points. We analyze transit data to develop a baseline vector on targeted households or buildings. We then compare this to billions of points of transaction data we acquire from data partners, at this point (once we observe multiple transactions) our algorithm determines that we can accurately target a house or building based on its public IP address. Our system typically matches about 50% of households for IP targeting; these are the households that we have the greatest confidence in the match between the IP address and location. If an IP is highly dynamic it simply never makes the cut to be included in an El Toro targeting segment.

If you have any further questions about IP addresses or how to use them to for advanced targeted of your digital advertising campaigns, please contact us.