Hostnames Overview
Almost all devices in your network have a hostname.
The hostname is the name that identifies the device on the network. A hostname is easier to remember than an IP address.
As an administrator, you follow conventions for naming devices. One such convention is to name the device based on its location—for example: germany-berlin-R1. Make the hostname unique within your local network so that users can connect to the device by using the hostname. You don't need to make the local hostname globally unique.
A device's hostname usually has a corresponding entry in the Domain Name
System (DNS) so that you (the administrator) can connect to the
device using the hostname. The fully qualified domain name
(FQDN), which is used in the DNS, includes the hostname and the
entire domain name. A period (or a dot) separates the hostname
and the domain name labels, so the FQDN format is
hostname.domain.
For example, if the hostname is
germany-berlin-R1
and the domain
name is example
, the FQDN is
germany-berlin-R1.example
. If the
example.net
domain is registered
and can be reached as example.net
on the
Internet, the FQDN for the device is
germany-berlin-R1.example.net
. The
FQDN is globally unique.
In Junos OS Evolved, the hostname can contain any combination of alphabetic characters, numbers, and dashes. No underscores or other special characters are allowed.
The software allows hostnames to contain up to 255 characters. Keep in mind that the total length of the hostname as an FQDN cannot exceed 255 characters (including the delimiting dots), with each domain name label having a maximum length of 63 characters. As a best practice, use short and meaningful hostnames, as long hostnames are difficult to type and to remember.
You can configure the hostname at the [edit
system]
hierarchy
level.