## example > nut.widget.com ## Details An FQDN is made up of the host name and a domain suffix. In the example, the host name is `nut` and the domain suffix is `widget.com`. This domain suffix consists of the domain name widget within the top-level domain `.com`. A domain suffix could also contain subdomains between the host and domain name. The trailing dot or period represents the root of the hierarchy. ## Rules - The host name must be unique within the domain. - The total length of an FQDN cannot exceed 253 characters, - with each label (part of the name defined by a period) no more than 63 characters (excluding the periods). - A [[DNS]] label should use letter, digit, and hyphen characters only. - A label should not start with a hyphen. Punctuation characters such as the period (.) or forward slash (/) should not be used. - [[DNS]] labels are not case sensitive. ## Find your FQDN ### Windows ```shell ipconfig /all ``` ### Linux ```bash hostname -fqdn ```