QFX3100 Director Device Overview
The Juniper Networks QFX3100 Director device is used to manage the Juniper Networks QFX3000-G and QFX3000-M QFabric systems.
You connect Gigabit Ethernet ports on a QFX3100 Director device to Gigabit Ethernet ports on Juniper Networks EX4200 Ethernet switches to form the control plane and management network for the QFabric system. The EX4200 switches interconnect the Juniper Networks QFX3500, QFX3600, and QFX5100 Node devices, Juniper Networks QFX3008-I or QFX3600-I Interconnect devices, and QFX3100 Director devices.
A QFabric system requires two QFX3100 Director devices interconnected as a QFX3100 Director group. The second QFX3100 Director device provides redundancy for the control plane and management network.
Software
In a QFabric system, most Routing Engine tasks for all devices in the QFabric system run on the QFX3100 Director device. The internal Routing Engines on each device in the QFabric system continue to be responsible for functions local to their own devices, such as environmental monitoring, system loading, and power management. The internal Routing Engines communicate with the QFX3100 Director group through the control plane network.
Physical Specifications
The QFX3100 Director device is two rack units (2 U) in size and designed to fit in industry-standard 19-inch rack mount enclosures. See Figure 1 and Figure 2.

The QFX3100 Director device has an LCD panel that displays the device name.

Network Modules
The QFX3100 Director device supports two network modules. Each network module contains four 1000BASE-T Gigabit Ethernet ports with RJ-45 connectors or four small form-factor pluggable (SFP) ports. The ports connect to the control plane and management network for the QFabric system. The ports on the network modules are also used to connect QFX3100 Director devices together to form a QFX3100 Director group.
Network modules are installed in the bottom module slots on the QFX3100 Director devices. All QFX3100 Director devices are shipped with two network modules. The network modules are field-replaceable but not hot-swappable. See Installing a Network Module in a QFX3100 Director Device.
Hard Disk Drive Modules
The QFX3100 Director device ships with two 2-terabyte (TB) hard disk drive (HDD) modules that provide storage for the Director device. The four HDD modules in the two QFX3100 Director devices participating in a Director group operate in a redundant array of independent disks (RAID) system to mirror data by synchronizing directories or files across the HDD modules.
HDD modules are installed in the upper module slots on the QFX3100 Director devices. All QFX3100 Director devices are shipped with two HDD modules. The HDD modules are field-replaceable and hot-swappable. See Installing an HDD Module in a QFX3100 Director Device.
AC Power Supplies
The QFX3100 Director device ships with redundant AC power supplies that provide power for the device. The power supply slots are located on the far right side of the rear panel of the QFX3100 Director device.
AC power supplies are field-replaceable and hot-swappable. See Installing a Power Supply in a QFX3100 Director Device (includes video).
Fan Modules
The QFX3100 Director device ships with three fan modules. The fan modules provide cooling to the system and are installed in the fan module slots on the rear panel of the QFX3100 Director device.
Fan modules are field-replaceable and hot-swappable. See Installing a Fan Module in a QFX3100 Director Device.