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EX Series Switches Interfaces Overview

Juniper Networks EX Series Ethernet Switches have two types of interfaces: network interfaces and special interfaces. This topic provides brief information on these interfaces. For additional information, see the Junos OS Interfaces Fundamentals Configuration Guide.

For information on interface-naming conventions on EX Series switches, see Understanding Interface Naming Conventions on EX Series Switches.

This topic describes:

Network Interfaces

Network interfaces connect to the network and carry network traffic. Table 1 lists the types of network interfaces supported on EX Series switches.

Table 1: Network Interface Types and Purposes

TypePurpose

Aggregated Ethernet interfaces

All EX Series switches allow you to group Ethernet interfaces at the physical layer to form a single link layer interface, also known as a link aggregation group (LAG) or bundle. These aggregated Ethernet interfaces help to balance traffic and increase the uplink bandwidth.

LAN access interfaces

Use these EX Series switch interfaces to connect a personal computer, laptop, file server, or printer to the network. When you power on an EX Series switch and use the factory-default configuration, the software automatically configures interfaces in access mode for each of the network ports. The default configuration also enables autonegotiation for both speed and link mode.

Power over Ethernet (PoE) interfaces

EX Series switches provide PoE network ports with various switch models. These ports can be used to connect voice over IP (VoIP) telephones, wireless access points, video cameras, and point-of-sale devices to safely receive power from the same access ports that are used to connect personal computers to the network. PoE interfaces are enabled by default in the factory configuration.

Trunk interfaces

EX Series access switches can be connected to a distribution switch or customer-edge (CE) switches or routers. To use a port for this type of connection, you must explicitly configure the port interface for trunk mode. The interfaces from the distribution switch or CE switch to the access switches must also be configured for trunk mode.

Special Interfaces

Table 2 lists the types of special interfaces supported on EX Series switches.

Table 2: Special Interface Types and Purposes

TypePurpose

Console port

Each EX Series switch has a serial port, labeled CON or CONSOLE, for connecting tty-type terminals to the switch using standard PC-type tty cables. The console port does not have a physical address or IP address associated with it. However, it is an interface in the sense that it provides access to the switch. On an EX3300 Virtual Chassis, an EX4200 Virtual Chassis, or an EX4500 Virtual Chassis, you can access the master and configure all members of the Virtual Chassis through any member's console port. For more information on the console port in a Virtual Chassis, see Understanding Global Management of an EX Series Virtual Chassis.

Loopback

All EX Series switches have this software-only virtual interface that is always up. The loopback interface provides a stable and consistent interface and IP address on the switch.

Management interface

The Juniper Networks Junos operating system (Junos OS) for EX Series switches automatically creates the switch's management Ethernet interface, me0. The management Ethernet interface provides an out-of-band method for connecting to the switch. To use me0 as a management port, you must configure its logical port, me0.0, with a valid IP address. You can connect to the management interface over the network using utilities such as SSH or Telnet. SNMP can use the management interface to gather statistics from the switch. (The management interface me0 is analogous to the fxp0 interfaces on routers running Junos OS.)

Routed VLAN Interface (RVI)

EX Series switches use a Layer 3 routed VLAN interface (RVI) named vlan to route traffic from one broadcast domain to another and to perform other Layer 3 functions such as traffic engineering. These functions are typically performed by a router interface in a traditional network.

The RVI functions as a logical router, eliminating the need for having both a switch and a router. The RVI (the vlan interface) must be configured as part of a broadcast domain or virtual private LAN service (VPLS) routing instance for Layer 3 traffic to be routed out of it.

Virtual Chassis port (VCP) interfaces

Virtual Chassis ports (VCPs) are used to interconnect switches in a Virtual Chassis:

Virtual management Ethernet (VME) interface

EX3300, EX4200, and EX4500 switches have a VME interface. This is a logical interface that is used for Virtual Chassis configurations and allows you to manage all the members of the Virtual Chassis through the master. For more information on the VME interface, see Understanding Global Management of an EX Series Virtual Chassis.

EX8200 switches do not use a VME interface. An EX8200 Virtual Chassis is managed through the management Ethernet (me0) interface on the XRE200 External Routing Engine.

Published: 2012-12-07