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Understanding QFX Series Virtual Chassis

 

This topic introduces QFX Series Virtual Chassis. A QFX Series Virtual Chassis is a supported combination of interconnected QFX3500, QFX3600, QFX5100, QFX5110, QFX5120 or EX4650, QFX5200, and EX4300 switches operating as one logical device and managed as a single chassis. Switches in a Virtual Chassis are called member switches of the Virtual Chassis.

This topic does not discuss Virtual Chassis Fabric (VCF). For information on understanding VCF, see Virtual Chassis Fabric Overview.

Virtual Chassis Support on QFX Series Switches

A QFX Series Virtual Chassis is a flexible, scaling switch solution for supported combinations of QFX3500, QFX3600, QFX5100, QFX5110, QFX5120, and QFX5200 switches. EX4650-48Y switches operate the same as QFX5120-48Y switches in a Virtual Chassis, so QFX Series Virtual Chassis configuration, monitoring and maintenance steps also apply to EX4650 Virtual Chassis. EX4300 switches can be included in some configurations of a QFX Series Virtual Chassis.

In a QFX Series Virtual Chassis, you can interconnect standalone switches in the following combinations into one logical device, and manage the logical device as a single chassis:

  • Up to three QFX5200 switches (a non-mixed Virtual Chassis)

    Note

    QFX5200 Virtual Chassis is supported only in Junos OS Release 17.3R2.

  • Two QFX5120 switches or up to four EX4650 switches (a non-mixed Virtual Chassis), as follows:

    • Starting in Junos OS Release 19.3R1, you can interconnect two QFX5120-48Y or EX4650-48Y switches into a Virtual Chassis.

    • Starting in Junos OS Release 19.4R1, you can interconnect up to four EX4650-48Y switches into a Virtual Chassis.

      Note

      Support for more than two EX4650-48Y switches in a Virtual Chassis is documented but not supported in Junos OS Release 19.4R1. You can form an EX4650 Virtual Chassis using up to two EX4650-48Y switches.

  • Up to ten QFX5110 switches or a combination of QFX5110 and QFX5100 switches (a non-mixed Virtual Chassis)

  • Up to ten QFX5100 switches (a non-mixed Virtual Chassis)

  • Up to ten QFX5100 switches with any combination of QFX3500, QFX3600, or EX4300 switches (a mixed-mode Virtual Chassis)

  • Up to ten QFX3500 switches or QFX3600 switches, or a combination of QFX3500 and QFX3600 switches (a non-mixed Virtual Chassis)

  • Up to ten QFX3500 or QFX3600 switches with supported EX4300 switches, or a combination of all three types of switches (a mixed-mode Virtual Chassis)

    Note

    EX4300 multigigabit model (EX4300-48MP) switches are not supported in a mixed-mode Virtual Chassis with any QFX Series switches.

Basic Configuration of QFX Series Virtual Chassis

Some QFX Series switches can only form a Virtual Chassis with the same type of switches, while others can be interconnected with other types of switches into a mixed-mode Virtual Chassis. See Understanding Mixed EX Series and QFX Series Virtual Chassis for details on the different types of switches that can be mixed in a Virtual Chassis.

You set up a Virtual Chassis by configuring Virtual Chassis ports (VCPs) on the member switches, and interconnecting the switches using the VCPs . VCPs are responsible for passing all data and control traffic between member switches in the Virtual Chassis.

The following ports on QFX Series switches that support Virtual Chassis can be configured into VCPs to form a QFX Series Virtual Chassis:

  • On QFX5200 switches: Any 40-Gigabit Ethernet QSFP+ ports

    Note

    In Junos OS Release 17.3R2-S4, 100-Gigabit Ethernet QSFP28 ports are also supported as VCPs on QFX5200 switches.

  • On QFX5120-48Y or EX4650-48Y switches: Only the four 40-Gigabit Ethernet QSFP+ or 100-Gigabit Ethernet QSFP28 front panel uplink ports (ports 48 through 55)

  • On QFX5110 switches: Any 40-Gigabit Ethernet QSFP+ or 100-Gigabit Ethernet QSFP28 ports

  • On QFX3500, QFX3600, or QFX5100 switches: Any non-channelized 40-Gigabit Ethernet QSFP+ ports

  • Any fixed 10-Gigabit Ethernet SFP+ ports on any QFX Series switches that support these ports

EX4650 and QFX Series switches don’t have any dedicated VCPs (ports that can only be used as VCPs) or default-configured VCPs (ports that are configured as VCPs in the default factory configuration). See Virtual Chassis Port Options for details on which ports on different QFX Series switches can be VCPs.

You can increase VCP bandwidth between member switches by connecting multiple VCP links between the switches. When multiple VCP links interconnect the same two member switches, the links automatically form a Link Aggregation Group (LAG) bundle if they have the same speeds. For example, if you have two 40-Gigabit Ethernet QSFP+ interfaces configured as VCPs between member switches, the two links form a LAG with 80-Gbps of total bandwidth. However, 10-Gigabit Ethernet SFP+ and 40-Gigabit Ethernet QSFP+ interfaces configured as VCPs between two Virtual Chassis member switches will not become member links in the same VCP LAG.

You can set up a Virtual Chassis using either a nonprovisioned or a preprovisioned configuration. If you want to deterministically control the role and member ID assigned to each member switch, use a preprovisioned configuration. Virtual Chassis member switches can have one of three roles: master Routing Engine, backup Routing Engine, or linecard role. In some combinations of switches in a Virtual Chassis, we recommend or require that you configure certain switches into the Routing Engine roles. See Understanding Virtual Chassis Components for more information about Virtual Chassis roles.

Adding switches to a preprovisioned configuration is simpler if you use the automatic VCP conversion feature (see Automatic Virtual Chassis Port (VCP) Conversion), which automatically converts uplink ports into VCPs on the member switches on both sides of the new VCP links as they are cabled. This method to expand a Virtual Chassis is also called autoprovisioning.

QFX5200 Switches in a Virtual Chassis

Virtual Chassis is supported on QFX5200 switches in Junos OS Release 17.3R2.

You can interconnect up to three QFX5200 switches into a QFX5200 Virtual Chassis. QFX5200 switches cannot be combined with other types of switches in a Virtual Chassis.

The following QFX5200 switches are supported in a QFX5200 Virtual Chassis:

  • QFX5200-32C

QFX5120 or EX4650 Switches in a Virtual Chassis

QFX5120 and EX4650 switches are similar and operate the same way in a Virtual Chassis. QFX5120 or EX4650 switches can’t be combined with any other type of switches in a Virtual Chassis.

  • Starting in Junos OS Release 19.3R1, you can interconnect two QFX5120-48Y switches or two EX4650-48Y switches into a Virtual Chassis. The two member switches must be in the master and backup Routing Engine roles.

  • Starting in Junos OS Release 19.4R1, you can interconnect up to four EX4650-48Y switches into a Virtual Chassis. We recommend that you configure two member switches in the master and backup Routing Engine roles for Routing Engine redundancy, and the remaining switches in linecard role.

    Note

    Support for more than two EX4650-48Y switches in a Virtual Chassis is documented but not supported in Junos OS Release 19.4R1. You can form an EX4650 Virtual Chassis using two EX4650 switches configured in the master and backup Routing Engine roles.

See Understanding Virtual Chassis Components for more information about Virtual Chassis member roles.

QFX 5120 and EX4650 switches do not have dedicated or default-configured VCPs, but you can set any of the following ports as VCPs on these switches:

  • On QFX5120-48Y or EX4650-48Y switches: Any of the 40-Gigabit Ethernet QSFP+ or 100-Gigabit Ethernet QSFP28 uplink ports on the front panel (non-channelized ports 48 through 55)

    Note

    You can’t use any of the other ports (network ports 0 through 47) as VCPs. Running the request virtual-chassis vc-port set command on the network ports doesn’t fail, but they will not function properly as VCPs.

You configure, monitor, and maintain a QFX5120 Virtual Chassis or an EX4650 Virtual Chassis in the same way as other QFX Series Virtual Chassis. See the following for more details:

QFX5110 Switches in a Virtual Chassis

Starting in Junos OS Release 17.3R1, QFX5110 switches support Virtual Chassis.

You can interconnect up to ten QFX5110 switches or a combination of QFX5110 and QFX5100 switches into a QFX5110 Virtual Chassis. All switches can run the same software image, and you do not need to configure mixed mode.

The following QFX5110 and QFX5100 switches are supported in a QFX5110 Virtual Chassis:

  • QFX5110-32Q

  • QFX5110-48S

  • QFX5100-24Q

  • QFX5100-48S

  • QFX5100-48T

    Starting in Junos OS Release 17.3R2, you can include QFX5100-48T switches in a QFX5110 Virtual Chassis.

  • QFX5100-96S

QFX5100 Switches in a Virtual Chassis

Starting in Junos OS Release 13.2X51-D20, QFX5100 switches support Virtual Chassis. You can interconnect up to ten switches into a QFX5100 Virtual Chassis that can include any combination of QFX5100, QFX3500, QFX3600, and EX4300 switches.

Note

In Junos OS release 13.2X51-D20, you can interconnect only up to four QFX5100-96S switches in a non-mixed QFX5100 Virtual Chassis. Starting in Junos OS release 13.2X51-D25, you can configure up to ten QFX5100-96S switches into a mixed or non-mixed QFX Series Virtual Chassis.

The following QFX5100 switches are supported in a non-mixed QFX5100 Virtual Chassis or a mixed QFX5100 Virtual Chassis (QFX5100 switches with QFX3500, QFX3600, or EX4300 switches):

  • QFX5100-24Q

  • QFX5100-48S

  • QFX5100-48T

  • QFX5100-96S

Note

You should configure QFX5100-24Q switches as the Routing Engine role member switches in a mixed QFX5100 Virtual Chassis.

QFX5100 switches can also be part of a QFX5110 Virtual Chassis, which can be a combination of up to ten QFX5110 and QFX5100 switches. For a QFX5100 switch to participate in a QFX5110 Virtual Chassis, the switch must have the same software version and image installed as the software running on the QFX5110 switches in the Virtual Chassis. You don’t need to configure mixed mode. In a QFX5110 Virtual Chassis, we recommend to use QFX5110 switches in the master and backup Routing Engine roles, and QFX5100 switches only in the line-card role.

The following QFX5100 switches are supported in a QFX5110 Virtual Chassis:

  • QFX5100-24Q

  • QFX5100-48S

  • QFX5100-48T

    Starting in Junos OS Release 17.3R2, you can include QFX5100-48T switches in a QFX5110 Virtual Chassis.

  • QFX5100-96S

Caution

You must first upgrade a QFX5100 switch running a Junos OS software image with “-qfx-5-” in the package filename to a Junos OS software image with “-qfx-5e-” in the package filename before it can be added to a QFX5110 Virtual Chassis or VCF. See Upgrading a QFX5100 Switch with a USB Device to Join a QFX5110 Virtual Chassis or Virtual Chassis Fabric.

QFX3500 and QFX3600 Switches in a Virtual Chassis

QFX3500 and QFX3600 switches support Virtual Chassis. To be included in a Virtual Chassis, you must configure QFX3500 and QFX3600 switches as standalone switches and not as QFX node devices in a QFabric system.

QFX3500 and QFX3600 switches can be in a Virtual Chassis with up to ten member switches in a non-mixed Virtual Chassis as follows:

  • All QFX3500 switches

  • All QFX3600 switches

  • A combination of QFX3500 and QFX3600 switches

QFX3500 or QFX3600 switches can also be in a mixed QFX5100 Virtual Chassis with any combination of QFX3500, QFX3600, QFX5100, and EX4300 switches.

Note

EX4300 multigigabit model (EX4300-48MP) switches are not supported in a mixed Virtual Chassis with QFX Series switches.

EX4300 Switches in a QFX Series Virtual Chassis

Starting in Junos OS Release 13.2X51-D20, EX4300 switches except multigigabit models (EX4300-48MP) can be interconnected into a mixed-mode QFX Series Virtual Chassis with up to ten member switches that can be any combination of EX4300, QFX3500 switches, QFX3600 switches, and QFX5100 switches.

Release History Table
Release
Description
Starting in Junos OS Release 19.4R1, you can interconnect up to four EX4650-48Y switches into a Virtual Chassis.
Starting in Junos OS Release 19.3R1, you can interconnect two QFX5120-48Y or EX4650-48Y switches into a Virtual Chassis.
In Junos OS Release 17.3R2-S4, 100-Gigabit Ethernet QSFP28 ports are also supported as VCPs on QFX5200 switches.
Virtual Chassis is supported on QFX5200 switches in Junos OS Release 17.3R2.
Starting in Junos OS Release 17.3R2, you can include QFX5100-48T switches in a QFX5110 Virtual Chassis.
Starting in Junos OS Release 17.3R1, QFX5110 switches support Virtual Chassis.
Starting in Junos OS release 13.2X51-D25, you can configure up to ten QFX5100-96S switches into a mixed or non-mixed QFX Series Virtual Chassis.
Starting in Junos OS Release 13.2X51-D20, QFX5100 switches support Virtual Chassis.
In Junos OS release 13.2X51-D20, you can interconnect only up to four QFX5100-96S switches in a non-mixed QFX5100 Virtual Chassis.
Starting in Junos OS Release 13.2X51-D20, EX4300 switches except multigigabit models (EX4300-48MP) can be interconnected into a mixed-mode QFX Series Virtual Chassis with up to ten member switches that can be any combination of EX4300, QFX3500 switches, QFX3600 switches, and QFX5100 switches.