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Mixed Virtual Chassis Fabric

A VCF with member switches from more than one product family is called a mixed VCF.

The following product families can be combined into a mixed QFX5100 VCF, which is a VCF where the spine devices are QFX5100 switches, and the leaf devices can be any of the following:

  • QFX5100 switches

  • QFX3500 and QFX3600 switches

  • EX4300 switches


A QFX5110 VCF, which is a VCF where the spine devices are QFX5110-32Q switches, can contain all QFX5110 switches or a mixture of QFX5110 and QFX5100 switches as leaf members. In either case, a QFX5110 VCF is considered to be a non-mixed VCF because both switch types run the same software image when interconnected into a QFX5110 VCF, and you are not required to set mixed mode. A QFX5110 VCF cannot include QFX3500, QFX3600, or QFX4300 switches.

The key benefits of allowing a mixed QFX5100 VCF include:

  • Diversification of supported interfaces as the devices broaden the mix of 1-Gbps, 10-Gbps, and 40-Gbps network ports available in the VCF.

  • Increased investment protection as previously purchased switches can be included in the VCF.

A QFX5100 VCF must use QFX5100 switches as spine devices, so a non-mixed QFX5100 VCF uses all QFX5100 switches as spine and leaf devices. A mixed QFX5100 VCF is any VCF that has at least one QFX3500, QFX3600, or EX4300 switch among the leaf devices.

The optimal QFX5100 VCF topology is to use a non-mixed VCF with QFX5100 switches only. A VCF composed entirely of QFX5100 switches supports the largest breadth of features available at the highest scalability and with the most high-speed interfaces as compared to QFX3500, QFX3600, and EX4300 switches. However, a mixed QFX5100 VCF gives you the flexibility to employ existing devices from your network as leaf devices.


The optimal VCF topology among all devices that support VCF technology is a QFX5110 VCF with all QFX5110 switches. A VCF composed entirely of QFX5110 switches supports the largest breadth of features available at maximum scalability with the highest speed interfaces. However, you also have the flexibility to employ existing QFX5100 switches from your network as leaf devices in a QFX5110 VCF.

All member switches in a mixed QFX5100 VCF must be configured into mixed mode using the request virtual-chassis mode mixed command. A device reboot is required for an update to the mixed mode setting to take effect. Mixed mode configuration is not required for a QFX5110 VCF that contains both QFX5110 and QFX5100 switches.

For more information on a mixed VCF, including the switches that can fulfill each role in a VCF, see Understanding Mixed Virtual Chassis Fabric.