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Understanding Mixed Virtual Chassis Fabric

 

This topic describes the requirements for a mixed Virtual Chassis Fabric (VCF). A VCF can be based on either QFX5110 switches as the spine members (a QFX5110 VCF) or QFX5100 switches as the spine members (a QFX5100 VCF). A mixed VCF is any VCF that includes two or more types of member switches in supported combinations that require you to configure mixed mode for the switches to interoperate in a VCF.

Virtual Chassis Fabric Mixed and Non-mixed Support Summary

Table 1 provides a high-level overview of the devices allowed in the Routing Engine and line-card roles of supported mixed and non-mixed VCF configurations. The switches in the Routing Engine role must be spine devices in a VCF topology. The table also includes license requirements and supported configuration methods.

Table 1: Virtual Chassis Fabric Summary

Category

Allowed Routing Engines

Allowed Line Cards

License Requirement

Configuration Methods

Non-mixed

QFX5110 (spine members must be QFX5110-32Q model switches)

QFX5110

QFX5100 (with a “-qfx-5e-” Junos OS image)

Yes, on two QFX5110 switches operating in master and backup Routing Engine roles

Autoprovisioning

Preprovisioning

Nonprovisioning (not recommended)

Non-mixed

QFX5100

QFX5100

Yes, on two QFX5100 switches operating in master and backup Routing Engine roles

Autoprovisioning

Preprovisioning

Nonprovisioning (not recommended)

Mixed

QFX5100

QFX5100

QFX3600

QFX3500

EX4300 (excluding EX4300 multigigabit models)

Yes, on two QFX5100 switches operating in master and backup Routing Engine roles

Autoprovisioning

Preprovisioning

Nonprovisioning (not recommended)

Understanding Mixed and Non-Mixed Virtual Chassis Fabric

A VCF can be based on either QFX5110 switches as the spine members (a QFX5110 VCF), or QFX5100 switches as the spine members (a QFX5100 VCF).

A mixed VCF is any VCF that includes two or more types of member switches in supported combinations for which you are required to configure mixed mode on all the switches for them to interoperate in a VCF. If you are converting a non-mixed VCF into a mixed VCF by adding members that are different types of devices in supported combinations, you must reboot the VCF to change the mixed mode setting on all members.

A non-mixed VCF has either all of the same type of switches or a combination of different switches that can run the same software image when in a VCF configuration. In this case you are not required set mixed mode on the member switches.

Note

The optimal QFX5110 VCF topology is to use QFX5110 switches only, and the optimal QFX5100 VCF topology is to use QFX5100 switches only. In each of these topologies, a VCF composed entirely of the base VCF devices supports the largest breadth of features at the highest scalability while also supporting the highest number of high-speed interfaces.

QFX5110 VCF

A QFX5110 VCF is any VCF that has QFX5110-32Q switches as the spine members, and the remaining members can be any combination of supported QFX5100 and QFX5110 member switches as leaf members. Any QFX5110 VCF, whether it has only QFX5110 members or includes both QFX5110 and QFX5100 switches, is considered to be a non-mixed VCF because both types of switches can run the same software image, and you do not need to configure mixed mode. The QFX5110 and QFX5100 switches must be running the same Junos OS image that includes “-qfx-5e-” in the filename when the Junos OS software package is downloaded from the Software Center.

Note

QFX5100 switches running a Junos OS image that includes “-qfx-5-” in the software package filename must be upgraded to the image filename that includes “-qfx-5e-” before being added to a QFX5110 VCF, or the VCF will not form. See Upgrading a QFX5100 Switch with a USB Device to Join a QFX5110 Virtual Chassis or Virtual Chassis Fabric.

Although the optimal method of configuring a QFX5110 VCF is as a VCF with QFX5110 devices only, you have the flexibility to configure a QFX5110 VCF that includes QFX5100 switches as leaf members.

Note

You must use QFX5110-32Q model switches as the spine members in a QFX5110 VCF.

QFX5100 VCF

A QFX5100 VCF is any VCF that has QFX5100 switches as the spine members, and the remaining members can be any combination of EX4300 (excluding EX4300 multigigabit models), QFX3500, QFX3600, or QFX5100 member switches as leaf members. If a QFX5100 VCF includes any of the other supported devices besides QFX5100 switches, it must operate as a mixed QFX5100 VCF, because the other devices run different software images, and you need to configure mixed mode.

Although the optimal method of configuring a QFX5100 VCF is as a non-mixed VCF with QFX5100 devices only, you have the flexibility to configure a mixed QFX5100 VCF with any combination of EX4300, QFX3500, and QFX3600 switches as leaf members.