IP Address

An Internet Protocol address (IP address) is a unique number assigned to every device on the Internet. This guide briefly covers what IP addresses do and provides more information on managing IP addresses at DreamHost.

Like a telephone number or street address, an IP address identifies networked devices and defines their location on a network like the Internet. There are currently two IP address versions

• IPv4 – The older protocol which is limited to the number of devices it can support.
• IPv6 – The newer replacement which supports significantly more devices and has been adopted over the last 10 years.

DreamHost provides both IP address versions and automatically assigns an IPv4 address to all active servers, services, and domains.

An IP address can be shared by multiple domains without issue. If necessary, a single Unique IP address can be assigned to any fully hosted domain using the DreamHost panel. A domain can also have multiple IP addresses assigned to its domain name system (DNS) records.

In the same way that an IP address is similar to a telephone number or street address, DNS is like a map or a phone book. It resolves easy to use domain names to the IP address to which they are assigned. IP addresses assigned to a domain can be changed either manually by you or automatically by DreamHost as a result of a server change.

There are two internetwork layer protocols in use by the Internet and supported by DreamHost:

IPv4

The most widely-deployed protocol, limited to 32-bit (4-byte) addresses normally expressed as 4 groups of decimal digits (e.g., 192.0.2.235). IPv4 allows for roughly 4.3 billion addresses and as the number of devices connected to the Internet increases, this limit is being reached. Assigning a Unique IPv4 address at DreamHost incurs an additional monthly cost due to the limited availability of IPv4 addresses.

IPv6

A new protocol with a 128-bit addressing scheme normally expressed as 8 groups of hexadecimal digits (e.g., 2001:0db8:85a3:08d3:1319:8a2e:0370:7334). IPv6 was created to manage the growth of the Internet and allows for roughly 3.4×1038 addresses. DreamHost currently offers free Unique IPv6 addresses.

In some circumstances, it may be useful or necessary to add a Unique IP address to a DreamHost-hosted domain. View the following article for further details:

• Unique IP overview

If you need to find your website’s IP address that DreamHost has assigned, you can view it in your panel. Visit the DreamHost DNS article for further instructions.

To view the IP address your domain is resolving to online, you can use either of the following links to check the propagation status:

• whatsmydns.net — A popular site that checks DNS records around the world.
• Viewing your DreamHost DNS records — Use DreamHost's DNS propagation checker in the panel.

View the following article for information on the 'Allowable Hosts' field:

• Managing MySQL users, allowable hosts, and privileges