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Interfaces Overview for Switches

 

Juniper Networks devices have two types of interfaces: network interfaces and special interfaces. This topic provides brief information about these interfaces. For additional information, see the Junos OS Network Interfaces Library for Routing Devices.

Network Interfaces for EX Series

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 Interfaces Types and Purposes for EX Series

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.

See Understanding Aggregated Ethernet Interfaces and LACP for Switches.

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.

See Understanding PoE on EX Series Switches.

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 network 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 for EX Series

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

Table 2: Special Interfaces Types and Purposes for EX Series

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 since 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 about the console port in a Virtual Chassis, see Understanding Global Management of a 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.)

See Understanding Management Interfaces.

Integrated Routing and Bridging (IRB) Interface or Routed VLAN Interface (RVI)

EX Series switches use an integrated routing and bridging (IRB) interface or Routed VLAN Interface (RVI) 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 IRB interface or RVI functions as a logical router, eliminating the need for having both a switch and a router. These interfaces must be configured as part of a broadcast domain or virtual private LAN service (VPLS) routing instance for Layer 3 traffic to be routed from.

See Understanding Integrated Routing and Bridging.

Virtual Chassis port (VCP) interfaces

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

  • EX3300 switches—Port 2 and port 3 of the SFP+ uplink ports are preconfigured as VCPs and can be used to interconnect up to six EX3300 switches in an EX3300 Virtual Chassis. See Setting an Uplink Port on an EX Series or QFX Series Switch as a Virtual Chassis Port.

  • EX4200 and EX4500 switches—Each EX4200 switch or each EX4500 switch with a Virtual Chassis module installed has two dedicated VCPs on its rear panel. These ports can be used to interconnect up to ten EX4200 switches in an EX4200 Virtual Chassis, up to ten EX4500 switches in an EX4500 Virtual Chassis, and up to ten switches in a mixed EX4200 and EX4500 Virtual Chassis. When you power on switches that are interconnected in this manner, the software automatically configures the VCP interfaces for the dedicated ports that have been interconnected. These VCP interfaces are not configurable or modifiable. See Understanding the High-Speed Interconnection of the Dedicated Virtual Chassis Ports Connecting EX4200, EX4500, and EX4550 Member Switches.

    You can also interconnect EX4200 and EX4500 switches by using uplink module ports. Using uplink ports allows you to connect switches over longer distances than you can by using the dedicated VCPs. To use the uplink ports as VCPs, you must explicitly configure the uplink module ports on the members you want to connect as VCPs. See Setting an Uplink Port on an EX Series or QFX Series Switch as a Virtual Chassis Port .

  • EX4300 switches—All QSFP+ ports are configured as VCPs by default. See Understanding EX Series Virtual Chassis.

    You can also interconnect EX4300 switches into a Virtual Chassis by using SFP+ uplink module ports as VCPs. Using uplink ports as VCPs allows you to connect switches over longer distances than you can by using the QSFP+ ports as VCPs. To use the uplink ports as VCPs, you must explicitly configure the uplink module ports on the members you want to connect as VCPs. See Setting an Uplink Port on an EX Series or QFX Series Switch as a Virtual Chassis Port.

  • EX8200 switches—EX8200 switches can be connected to an XRE200 External Routing Engine to create an EX8200 Virtual Chassis. The XRE200 External Routing Engine has dedicated VCPs that connect to ports on the internal Routing Engines of the EX8200 switches and can connect to another XRE200 External Routing Engine for redundancy. These ports require no configuration. .

    You can also connect two members of an EX8200 Virtual Chassis so that they can exchange Virtual Chassis Control Protocol (VCCP) traffic. To do so, you explicitly configure network ports on the EX8200 switches as VCPs.

Virtual management Ethernet (VME) interface

EX3300, EX4200, EX4300, 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 about the VME interface, see Understanding Global Management of a 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.

Network Interfaces for EX4600, NFX Series, QFX Series, QFabric System

Network interfaces connect to the network and carry network traffic. Table 3 lists the types of network interfaces supported.

Table 3: Network Interfaces Types and Purposes for EX4600, NFX Series, QFX Series, QFabric System

TypePurpose

Aggregated Ethernet interfaces

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.

Channelized Interfaces

Depending on the device and software package, 40-Gbps QSFP+ ports can be configured to operate as the following types of interfaces:

  • 10-Gigabit Ethernet interfaces (xe)

  • 40-Gigabit Ethernet interfaces (et and xle)

  • 40-Gigabit data plane uplink interfaces (fte)

When an et port is channelized to four xe ports, a colon is used to signify the four separate channels. For example, on a QFX3500 standalone switch with port 2 on PIC 1 configured as four 10-Gigabit Ethernet ports, the interface names are xe-0/1/2:0, xe-0/1/2:1, xe-0/1/2:2, and xe-0/1/2:3

Note: You cannot configure channelized interfaces to operate as Virtual Chassis ports.

Ethernet Interfaces

Configure Gigabit Ethernet, 10-Gigabit Ethernet, 40-Gigabit Ethernet interfaces to connect to other servers, storage, and switches. You can configure 40-Gigabit data plane uplink ports to connect a Node device to an Interconnect devices as well as for Virtual Chassis ports (VCPs).

Fibre Channel interfaces

Use Fibre Channel interfaces to connect the switch to a Fibre Channel over Ethernet (FCoE) forwarder or a Fibre Channel switch in a storage area network (SAN). You can configure Fibre Channel interfaces only on ports 0 through 5 and 42 through 47 on QFX3500 devices. Fibre Channel interfaces do not forward Ethernet traffic.

See Overview of Fibre Channel.

LAN access interfaces

Use these interfaces to connect to other servers, storage, and switches. When you power on a QFX Series product and use the factory-default configuration, the software automatically configures interfaces in access mode for each of the network ports.

Multichassis aggregated Ethernet (MC-AE) interfaces

Group a LAG on one standalone switch with a LAG on another standalone switch to create a MC-AE. The MC-AE provides load balancing and redundancy across the two standalone switches.

Tagged-access mode interfaces

Use tagged-access interfaces to connect a switch to an access layer device. Tagged-access interfaces can accept VLAN-tagged packets from multiple VLANs.

Trunk interfaces

Use trunk interfaces to connect to other 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 switches or routers must also be configured for trunk mode. In this mode, the interface can be in multiple VLANs and accept tagged packets from multiple devices. Trunk interfaces typically connect to other switches and to routers on the LAN.

Virtual Chassis ports (VCPs)

You can use Virtual Chassis ports to send and receive Virtual Chassis Control Protocol (VCCP) traffic, and to create, monitor, and maintain the Virtual Chassis. On QFX3500, QFX3600, QFX5100, QFX5110, QFX5200, and EX4600 standalone switches, you can configure 40-Gigabit Ethernet QSFP+ uplink ports (non-channelized) or fixed SFP+ 10-Gigabit Ethernet ports as VCPs by issuing the request virtual-chassis-vc-port-set CLI command. QFX5110 switches also support configuring 100-Gigabit QSFP28 ports as VCPs.

Special Interfaces for EX4600, NFX Series, QFX Series, QFabric System

Table 4 lists the types of special interfaces supported.

Table 4: Special Interfaces Types and Purposes supported on EX4600, NFX Series, QFX Series, QFabric System

TypePurpose

Console port

Each device has a serial console port, labeled CON or CONSOLE, for connecting tty-type terminals to the switch. 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.

Loopback interface

A 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 management Ethernet interface provides an out-of-band method for connecting to a standalone switch and QFabric system.

Note: On OCX Series switches, the em0 management interface always has the status up in show command outputs, even if the physical port is empty. The me0 interface is a virtual interface between Junos and the host operating system, therefore its status is independent from the status of the physical port.

Routed VLAN interfaces (RVI and IRB interfaces)

Layer 3 routed VLAN interfaces (called RVI in the original CLI, and called IRB in Enhanced Layer 2 Software) route traffic from one broadcast domain to another and perform other Layer 3 functions such as traffic engineering. These functions are typically performed by a router interface in a traditional network.

The RVI or IRB functions as a logical router, eliminating the need for having both a switch and a router. The RVI or IRB 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.

Network Interfaces for OCX Series

Network interfaces connect to the network and carry network traffic. Table 5 lists the types of network interfaces supported.

Table 5: Network Interfaces Types and Purposes for OCX Series

TypePurpose

Aggregated Ethernet interfaces

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.

Ethernet Interfaces

Configure Gigabit Ethernet, 10-Gigabit Ethernet, 40-Gigabit Ethernet interfaces to connect to other servers, storage, and switches.

Special Interfaces for OCX Series

Table 6 lists the types of special interfaces supported.

Table 6: Special Interfaces Types and Purposes for OCX Series

TypePurpose

Console port

Each device has a serial console port, labeled CON or CONSOLE, for connecting tty-type terminals to the switch. 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.

Loopback interface

A 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 management Ethernet interface provides an out-of-band method for connecting to a standalone switch and QFabric system.

Note: On OCX Series switches, the em0 management interface always has the status up in show command outputs, even if the physical port is empty. The me0 interface is a virtual interface between Junos and the host operating system, therefore its status is independent from the status of the physical port.