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.
If you're looking for what IP addresses to point your site to, view the following article:
What are IP addresses? What do they do?
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.
Internet Protocol versions
There are two internetwork layer protocols in use by the Internet and supported by DreamHost:
- 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.
- 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.
Adding a Unique IP address to a fully hosted domain
In some circumstances, it may be useful or necessary to add a Unique IP address to a DreamHost-hosted domain. For example, a Unique IP address is required in order to add Anonymous FTP to a domain. View the following article for further details:
Finding a website's IP address
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 an online tool such as this:
Whitelisting IP addresses for a MySQL server
View the following article for information on the 'Allowable Hosts' field:
- Website tools
- DreamHost DNS overview
- Previewing your site with a dreamhosters.com subdomain before changing DNS
- How to view your DreamHost site using your hosts file