Have questions about static IP addresses? Check out the top FAQs.
Devices on the Internet use IP addresses to locate and talk to each other on the Internet, much the same way people use phone numbers to call someone, street addresses for sending mail, and e-mail addresses to send electronic messages to a specific person. There are two kinds of IP addresses: static and dynamic.
A dynamic IP changes. A static IP does not change.
So that your public IP address will not change. You may want to consider a static IP address if you:
If you lease a single static IP address, it only provides a public IP address to the modem. If you need a public IP address on a device behind your high-speed Internet modem, you will need to lease a block of IP addresses.
When you lease a block of IP addresses, three IP addresses are reserved for routing. The other IP addresses can be assigned to devices behind your DSL modem.
You can lose your Static IP(s) in the following scenarios:
When you call CenturyLink to move your services, let us know that you have a "static IP lease", and that you want to keep them. At that time, we'll see if your current static IP(s) can be moved to your new location.
If you change your ISP, you will lose your static IP(s).
Registering your static IPs with ARIN is a good idea because it:
DNS (Domain Name System) is a directory that translates names to numbers. It is like a phone book for the Internet. DNS translates a domain name (e.g. www.centurylink.com) to the internet IP address at which the web site with that domain name is hosted (e.g. 22.214.171.124). Without DNS, you would need to know the IP address to get to a specific web site. However, DNS 'looks up' the address typed in to the address bar and translates it to the IP address for you, so the appropriate web page can be found and displayed.
Reverse DNS (rDNS) is the opposite directory from DNS. It translates numbers to names. rDNS translates an IP address to a domain name. The original use of the rDNS was mainly for network troubleshooting. More recently rDNS has been used as an anti-spam technique.
Some email servers may view email as spam if it originates from an IP address that does not have rDNS configured. In more extreme situations, the receiving email server will compare the originating IP address, the domain name that is listed as the sender, and then check for a rDNS record pointing back to the sender's domain name.