IPv4 and IPv6
- IPv4: four numbers from 0 to 255, such as 192.0.2.10. There are only about 4.3 billion of them, and they have run out.
- IPv6: longer addresses written in hexadecimal, such as 2001:db8::1, with room for practically unlimited devices.
Public, private, dynamic and static
- Public addresses are reachable on the internet; private ones, such as 192.168.x.x, are used inside home and office networks.
- Dynamic addresses change from time to time; static ones stay the same, which servers need.
IP addresses and SEO
Sharing a server IP address with other websites doesn’t hurt rankings. What matters is that the site is reachable, fast and served on its domain rather than its bare IP address: make sure requests to the server’s IP address redirect to the domain, so duplicate copies of the site don’t get indexed. IP addresses are also used to estimate a visitor’s location, and in the EU they count as personal data.
IP address example
Your website is hosted on a server at 203.0.113.10. The DNS record for example.com points to that number. If you move to a new host, you change the record to the new IP address. Visitors still type example.com and never notice. On the other side, your web server log shows each visitor’s IP address, which can help find where bots and attackers come from.
IP address checklist for site owners
- Know the IP address of your server and your DNS provider.
- If you use a CDN, remember that logs may show the CDN’s addresses unless you configure real visitor IP headers.
- Block abusive IP addresses at the firewall, not by hand in many files.
- Treat IP addresses as personal data where privacy laws apply, and set a log retention period.
- Exclude your own IP address from analytics so your visits do not count.
IP address mistakes
- Blocking a shared IP range and shutting out real visitors.
- Assuming an IP address identifies a person. Many people share one.
- Assuming a separate dedicated IP gives a ranking advantage. It does not.
IP address FAQs
Does my IP address affect SEO?
Not directly. A reliable, fast server matters. See DNS and CDNs.
What is the difference between IPv4 and IPv6?
IPv6 is the newer, longer format. Both work on the web. See user agents and crawlers.