This chapter discusses some of the ways in which both users and management systems can interact with an SRX device. At this point in the book, you must be familiar with the command-line interface (CLI), which provides a text-based interface between the users and the different subsystems in a device. This is our starting point: the management infrastructure and how the CLI interacts with the different system components.
Central to the Junos management infrastructure is a daemon that interacts with the different daemons and forwarding elements in a device, called the MGD (management daemon). This daemon is in charge of performing multiple common tasks on all management interfaces.
Most management interfaces, such as J-Web and the CLI, communicate with MGD by sending XML-formatted commands (procedure calls) and receiving the results, also in XML format. Each user interface then presents the information back to the user in a human-readable way, as shown in Figure 13-1.
Figure 13-1. The management infrastructure
Given its central placement in the system, MGD is the interface between the different system daemons and the management interfaces, so when MGD receives a request, it deals with interfacing to the appropriate daemons. In this sense, MGD abstracts the complexity of the system so that the client applications do not need to keep ...