VLANs and Interfaces | Introduction to Juniper and JNCIA Part 3

Like any other network device, Juniper devices can have physical or virtual interfaces. An ‘IFD’ is a physical device, and ‘IFL’ is a logical device. Each of these contain an address family (IFF) and an address entry (IFA). The interfaces follow a pattern. This is ‘type-x/y/z’. Type is the interface type, such as ‘ge’ for gigabit ethernet. X is the FPC number (AKA, the line-card), Y is the module or slot, and Z is the port number. Juniper also have a few special ‘permanent interfaces’ which are used for special purposes, like PIM (multicast), gre (tunnels), and others. Every interface is configured with a unit and a family. You can think of a unit as the logical configuration that goes on a physical interface. Multiple units means multiple sub-interfaces. Families refer to the type of logical interface. For example, the inet family is used for IPv4 configuration. IP addresses and VLAN ID’s are configured under the appropriate family. If you have multiple addresses on a single unit and family, you will need to consider which addresses are ‘primary’ and ‘preferred’. VLANs are simple to configure. They have a name, and a VLAN ID. An IP address can be bound to this if needed. Ports can be configured as access ports or trunk ports. If VLAN tagging is configured on a physical interface, then we’re able to use units to create multiple logical sub-interfaces. There are three parts to configuring a voice port. These are (1) a voice VLAN, (2) Power over Ethernet, or PoE, and (3...