IP Version 4 (IPv4)

IPv4 specifies an IP address as a 32-bit number, displayed most commonly in dotted decimal format (e.g. 1.2.3.4) for easier human readability. The dotted decimal format is also known as a quad octet, as it represents four (quad) groups of eight bits (octet).

Example:

An IP address, displayed as 32-bit number:    10101010101010101010101010101010

Same IP address, displayed in dotted decimal format:    170.170.170.170

Reserved IP Addresses

Some IP addresses are reserved to serve a special purpose and should not be assigned to any network device. These IP addresses are:

0.0.0.0  -  Default gateway

255.255.255.255  -  Broadcast

127.0.0.1  -  Local host / loopback

IP Version 6 (IPv6)

IPv6 specifies an IP address as a 128-bit number, displayed most commonly in eight groups of four hexadecimal strings separated by colons.

Example:

An IPv4 address:  128.128.128.128

An IPv6 address:  0123:4567:89ab:cdef:0123:4567:89ab:cdef

Hostnames are not strictly required for hosts to communicate with one another. However, many network services use or require hostnames when servicing requests.

Example:

• A network router routes traffic to and from other routers without ever relying on the hostnames of the other routers. In this case, hostnames do not need to be assigned to any of the routers.

How Can I Find My Hostname?

Internet Hostname: Since you’re already here, the easiest way of finding your Internet hostname is by visiting our homepage (click here). The MyHostname.com homepage displays your Internet hostname, IP address, and Web browser near the top of the page, where it’s quick and easy to see.

My Computer’s Hostname: There are various methods to finding your computer’s hostname, depending on its operating system. We outline some common ways of doing this below.

Windows 2000/XP/Vista/7/2003

1. Click the Start button (2000/XP/2003) or Windows button (Vista/7) to display the menu list.
2. Find ‘My Computer’ (2000/XP/2003) or ‘Computer’ (Vista/7) from the menu list. Right-click on ‘My Computer’/'Computer’ to display the action menu. Example:
   

   Windows XP: Right-click My Computer. Click Properties.

3. Click on ‘Properties’ at the bottom of the action menu. This will open the Systems Properties window.
   

   Windows XP: Systems Properties Window

4. In Windows 2000/XP/2003, the Systems Properties window uses a tabbed interface. Click on the ‘Computer Name’ tab. Your computer name is displayed in the ‘Full computer name’ field. In the example, above, the computer name is: vxp-sp3.
5. In Windows Vista/7, the computer name settings are displayed in the ‘Computer name, domain, and workgroup settings’ section.

Mac OSX

1. From Finder, go to Applications –> Utilities (or press the shortcut, Command-U).
2. Run the Terminal application. This will open a new terminal window.
3. By default, the prompt already displays your computer hostname, current directory, and username. Example:

   myhostname:directory-name stephenc$

4. Use the hostname command to determine your computer’s full hostname, including domain name (if any). At the prompt, type hostname and press Return. The resulting value is your computer’s full hostname. Example:

   myhostname:directory-name stephenc$ hostname
   myhostname.codecentral.com

   Note: Your computer’s full hostname may not include a domain name portion. This will depend on your computer’s individual configuration.