Chapter 4. Interfaces

This chapter describes the interface configurations for a Juniper Networks router. It starts with a description of the types of interfaces, the naming conventions, and the interface properties. It then identifies how to configure a large variety of interface media, such as T1 interfaces, Ethernet, and Serial interfaces. Lastly, it examines common interface problems, concentrating on the tools available to detect these issues.

Before you begin to design a network’s routing topology, you should ensure that all the proper physical connections are in place and are operational. With such a large variance in interface types, this can often be a challenging task, so it is important to understand how an interface is organized within the Junos network operating system.

Juniper Networks routers contain two major categories of interfaces: permanent and transient. Users cannot remove permanent interfaces, whereas they can move, change, and remove transient interfaces. Other technical differences exist that are evident when you examine the applications for each interface type.

The interface topics covered in this chapter include:

• Permanent interfaces

• Transient interfaces

• Interface properties

• Interface configuration examples

• Interface troubleshooting