Static IP and IPv6 FAQs

Devices on the internet use IP addresses to locate and talk to each other, much the same way we use phone numbers or e-mail addresses to talk to or send electronic messages to specific people.

There are two kinds of IP addresses: static and dynamic. Static means the address doesn't change, and dynamic means it does change.

Unfortunately, we cannot move your static IP if you move your CenturyLink service to a new address.

ARIN (American Registry for Internet Numbers) is a nonprofit corporation that manages the distribution of IP addresses for most of North America. (For additional information see www.arin.net)

Registering your static IPs with ARIN is a good idea because it:

• Avoids duplicate distribution
• Ensures traffic routing

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. 155.70.40.251). 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.

When you lease a static IPv4 address, those addresses have 'derived IPv6' addresses associated to them, so there is no need to order anything else. But, you will need to enable IPv6 on your modem.

The lease on existing static IP addresses continues until you either choose to delete them from your account, or until you cancel or move your CenturyLink internet service.

We are no longer leasing new static IP addresses.

Please contact us to cancel a static IP lease. If you had a single static IP, you do not need to reconfigure your modem. Customers with an IP block will need to re-configure the modem.

If you cancel a single static IP lease, you do NOT need to reconfigure your modem.

If you cancel a static IP block and your modem was configured for that block, you will need to reconfigure your modem to use a dynamic IP.  Follow the instructions for PPPoE Setup > PPPoE with dynamic IP from the modem's WAN settings.

IPv6 is the latest version of the Internet Protocol (IP) that is the basis of how the internet is built and how it runs.

The internet was originally designed using IPv4, but after several years of enormous growth, it started to look like the world would run out of IP addresses. In 1998, IP version 6 (IPv6) was standardized. Simply put, version 6 gives the internet more IP addresses and additional features.

All IPv4 addresses typically have a "derived IPv6 address" associated with them.

Yes, the two types have different strucures.

IPv4 addresses contain only numbers in groups of two or three, separated by periods, like this: 62.157.9.98

IPv6 addresses use 4-digit groups of letters or numbers, separated by colons, like this: 2002:3e9d:9062:0001:1

To troubleshoot IPv6:

• Make sure your modem is IPv6 capable. If IPv6 is not listed in the features section, chat with customer service to review your options.
  
• Enable IPv6 on your modem
• Test your IPv6 connection

CenturyLink's IPv6 address space is: 2602:0/24