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Spine and Leaf Recommendations

Spine and leaf device recommendations vary by type of VCF and the needs of your network.

A VCF can be set up with QFX5100 switches as the spine devices, referred to as a QFX5100 VCF, or using QFX5110-32Q switches as the spine devices, referred to as a QFX5110 VCF:

  • A QFX5100 VCF has QFX5100 switches as spine members, and supports either all QFX5100 switches as leaf members (a non-mixed QFX5100 VCF), or any combination of EX4300, QFX3500, and QFX3600 switches, possibly with additional QFX5100 switches, as leaf members (a mixed-mode QFX5100 VCF).


    EX4300 multigigabit models (EX4300-48MP) are not supported in a VCF.

  • A QFX5110 VCF supports QFX5110-32Q switches as spine members, and supports either all QFX5110 switches or any combination of supported QFX5100 switches and QFX5110 switches as leaf members. Both QFX5110 and QFX5100 switches run the same software image in a QFX5110 VCF, and do not require configuring mixed mode to interoperate.

QFX5100 VCF Spine and Leaf Recommendations

Table 1 provides a list of recommended switches for a QFX5100 VCF based on the server attachment speeds of the servers in your data center.

Other combinations of spine and leaf switches are supported; consider the device combinations in this table as recommendations only.

QFX5110 VCF Spine and Leaf Recommendations

In a QFX5110 VCF:

  • Spine devices should be QFX5110-32Q switches, so as a result, the members acting as primary and backup in the Routing Engine role are QFX5110-32Q switches.

  • Leaf devices can be QFX5110-32Q, QFX5110-48S switches, or any of the following QFX5100 switches:

    • QFX5100-24Q

    • QFX5100-48S

    • QFX5100-48T (starting in Junos OS Release 17.3R2)

    • QFX5100-96S

QFX5110 switches in a QFX5110 VCF have flexible port options for server attachments, uplink ports, and VCPs for VCF member interconnection.

QFX5110 switches support a small number of 100-Gbps ports that are usually used as uplink ports, but can be used as VCPs as well. QFX5110 switches also have 1-Gbps, 10-Gbps, and 40-Gbps port options. See the QFX5110 hardware documentation as follows for details on the ports supported on QFX5110 switches that can be used, as needed, as uplink ports or VCPs to take advantage of higher port speeds, and independent and channelized port options that can be used as server access ports on leaf or spine members:

Guidelines for using ports on QFX5100 leaf members in a QFX5110 VCF for different speed server connections in your network are similar to those listed in Table 1 for a QFX5100 VCF.