How to Find ISP Addresses

An Internet Service Provider (ISP) address is the web address of the company that provides internet access to subscribers. Services including dial-up telephone modems, digital subscriber line (DSL) wires, television cables and fiber optics are provided to customers wanting to connect to the internet. With an ISP address, you can find out exactly who sold internet access to a person or the company that hosts a website. There are a number of domain-based research services, including NetworkSolutionsWhoIs.net (Network Solutions Who Is), IP2Location.com (IP 2 Location), and IP-Adress.com (IP-Address).

Go to the networksolutions.com/whois website. Enter a domain name in the search field - networksolutions.com, for example.

Click "Search" to search all WHOIS records. Use the free service to find IP addresses as well as service provider information for websites. It is important to note that an ISP address is the name of the company providing internet access. An IP address would appear as "11.22.33.444," for example, but an ISP address would appear as "Registrant: Road Runner HoldCo, LLC (RR6-DOM)."

Scroll as needed to review registrant information. Find the Current Registrar to get the name of the ISP, such as GoDaddy or RR (RoadRunner). In the case of networksolutions.com, the current registrar, as of 2009, is NETWORK SOLUTIONS, LLC. The IP address is listed as 205.178.187.13 (ARIN & RIPE IP search).

Type the name of the company through whom the website is registered into a web browser. In the case of NetworkSolutions, you could go to Yahoo.com and type "Network Solutions LLC." For Network Solutions LLC, the ISP address is www.networksolutions.com. If Road Runner were the company, the ISP address would be www.rr.com.

Go to IP-Adress.com.

Locate "My Ip Address." Expect to see a nine-digit number, such as 11.22.33.444. Locate "My IP Address Location." This line should immediately follow the above line.

Locate, "ISP of my IP:" For example, Road Runner could appear as an ISP of an IP.

Type "Road Runner" into a search engine to obtain the ISP address of the Road Runner company. A quick search would show that www.rr.com is the ISP address of the Road Runner company.