Understanding Management Ethernet Interfaces
Management interfaces are the primary interfaces for accessing the device remotely. Typically, a management interface is not connected to the in-band network, but is connected instead to the device's internal network. Through a management interface you can access the device over the network using utilities such as ssh and telnet and configure the device from anywhere, regardless of its physical location. SNMP can use the management interface to gather statistics from the device.
A management interface lets authorized users and management systems connect to the device over the network. Some Juniper Networks devices have a dedicated management port on the front panel. For other types of platforms, you can configure a management interface on one of the network interfaces. This interface can be dedicated to management or shared with other traffic. Before users can access the management interface, you must configure it. Information required to set up the management interface includes its IP address and prefix. In many types of Junos OS devices (or recommended configurations), it is not possible to route traffic between the management interface and the other ports. Therefore, you should select an IP address in a separate (logical) network, with a separate prefix (netmask).
For Junos OS Evolved, use re0:mgmt-* for Routing Engine 0 and re1:mgmt-* for Routing Engine 1 management interfaces.