juniper QFX Series QFX5120-48T
The Juniper QFX5120-48T is an enterprise 1U datacenter top-of-rack leaf switch delivering 48 ports of 100M/1G/10GBASE-T twisted-pair copper and 6 ports of 40G/100G QSFP28 uplinks. Built on Broadcom Trident 3 silicon, the switch provides 2.16 Tbps of switching throughput with full EVPN-VXLAN support. The QFX5120-48T is specifically engineered for enterprise server farms utilizing existing copper structured cabling that require 10G server access and 100G fabric connectivity.
Specifications
| Brand | juniper |
|---|---|
| Family | QFX Series |
| Form factor | 1U fixed switch |
| Released | Mar 2019 |
| Ports | 48x 100M/1G/10GBASE-T RJ-45 ports and 6x 40G/100G QSFP28 uplinks |
| Switching capacity | 2.16 Tbps / 1.6 Bpps wire-speed forwarding performance |
| Cabling | Standard Cat6/Cat6a RJ-45 twisted-pair copper connectivity |
| Fabric support | Hardware-based EVPN-VXLAN Layer 2 and Layer 3 gateway architecture |
| Redundancy | Dual hot-swappable AC or DC power modules and reversible fan trays |
Works together
How the juniper QFX Series QFX5120-48T connects to servers, storage and the network: 3 ways, with the parts and products on each path.
iSCSI and NVMe/TCP over Ethernet
Keep the speed the same at all three points: a 25GbE server, a 25GbE switch port and a 25GbE array port. Mixed speeds work but the slowest link sets the pace.
Servers
Dell PowerEdge R6515 1U rack
Dell PowerEdge R7515 2U rack
HPE Edgeline EL8000 5U ruggedized edge system
HPE ProLiant DL160 Gen10 1U rack
HPE ProLiant DL180 Gen10 2U rack
Lenovo ThinkSystem SE350 1U rack
Adapters for the server
BCM957416A4160C Broadcom NetXtreme-E BCM57416 Dual-Port 10GBASE-T PCIe 3.0 Ethernet Network Adapter
540-BBGN Dell Broadcom 57412 Dual Port 10GbE SFP+ PCIe Adapter
540-BBGO Dell Broadcom 57416 Dual Port 10GBASE-T RJ45 PCIe Adapter
540-BBGP Dell Broadcom 57416 Dual Port 10GBASE-T RJ45 OCP 3.0 Adapter
Storage
Dell Unity XT 380F 2U rack
Dell Unity XT 380XT 2U rack
Dell Unity XT 480F 2U rack
Dell Unity XT 480XT 2U rack
Dell Unity XT 680F 2U rack
Dell Unity XT 680XT 2U rack
Optics
SFP-10G-SR-AR Arista 10GBASE-SR SFP+ Optical Transceiver
SFP-10G-SR Cisco 10GBASE-SR SFP+ Optical Transceiver
407-BBOU Dell 10GbE SFP+ SR Optical Transceiver (850nm, 300m MMF)
File storage (NFS and SMB)
Front-end ports face the clients; back-end ports (on scale-out systems) connect the nodes to each other and need their own switch pair.
Servers
- Dell PowerEdge R6515 1U rack
- Dell PowerEdge R7515 2U rack
- HPE Edgeline EL8000 5U ruggedized edge system
- HPE ProLiant DL160 Gen10 1U rack
- HPE ProLiant DL180 Gen10 2U rack
- Lenovo ThinkSystem SE350 1U rack
Adapters for the server
- BCM957416A4160C Broadcom NetXtreme-E BCM57416 Dual-Port 10GBASE-T PCIe 3.0 Ethernet Network Adapter
- 540-BBGN Dell Broadcom 57412 Dual Port 10GbE SFP+ PCIe Adapter
- 540-BBGO Dell Broadcom 57416 Dual Port 10GBASE-T RJ45 PCIe Adapter
- 540-BBGP Dell Broadcom 57416 Dual Port 10GBASE-T RJ45 OCP 3.0 Adapter
Storage
- Dell Unity XT 380F 2U rack
- Dell Unity XT 380XT 2U rack
- Dell Unity XT 480F 2U rack
- Dell Unity XT 480XT 2U rack
- Dell Unity XT 680F 2U rack
- Dell Unity XT 680XT 2U rack
Optics
- SFP-10G-SR-AR Arista 10GBASE-SR SFP+ Optical Transceiver
- SFP-10G-SR Cisco 10GBASE-SR SFP+ Optical Transceiver
- 407-BBOU Dell 10GbE SFP+ SR Optical Transceiver (850nm, 300m MMF)
Hyperconverged cluster
Plan at least two 25GbE ports per node to two switches; all-NVMe clusters often move to 100GbE.
HCI nodes
HPE SimpliVity 325 Gen10 1U rack
HPE SimpliVity 380 Gen10 G 2U rack
HPE SimpliVity 325 Gen10 Plus v2 1U rack
Lenovo ThinkAgile VX650 V2 2U rack
Adapters for the server
- BCM957416A4160C Broadcom NetXtreme-E BCM57416 Dual-Port 10GBASE-T PCIe 3.0 Ethernet Network Adapter
- 540-BBGN Dell Broadcom 57412 Dual Port 10GbE SFP+ PCIe Adapter
- 540-BBGO Dell Broadcom 57416 Dual Port 10GBASE-T RJ45 PCIe Adapter
- 540-BBGP Dell Broadcom 57416 Dual Port 10GBASE-T RJ45 OCP 3.0 Adapter
Optics
- SFP-10G-SR-AR Arista 10GBASE-SR SFP+ Optical Transceiver
- SFP-10G-SR Cisco 10GBASE-SR SFP+ Optical Transceiver
- 407-BBOU Dell 10GbE SFP+ SR Optical Transceiver (850nm, 300m MMF)
Plan and size it
- Draw this setup in the topology planner mrplanb.com
- Add up rack power and space rack-density.com
- iSCSI explained mrplanb.com
- Virtualization storage Ledger: scored storage platforms mrplanb.com
- Network monitoring tools compared mrplanb.com
Check compatibility with Juniper
Before you buy, confirm the exact configuration against the vendor's own lists: firmware levels, operating systems, adapters and optics that Juniper has tested with the juniper QFX Series QFX5120-48T.
- Compatibility Juniper Hardware Compatibility Tool (optics and modules)
- Specifications Juniper TechLibrary
- Support Juniper Support
Equivalent models from other brands
FAQ
What cable grades are required for 10GBASE-T on the QFX5120-48T?
Cat6 supports 10G up to 55 meters, while Cat6a or Cat7 supports 10G up to 100 meters.
Can the 100GbE QSFP28 ports be broken out to 4x 25GbE?
Yes, QSFP28 ports support 4x 25GbE or 4x 10GbE breakout cables for additional high-speed connectivity.
Buying or selling QFX5120-48T?
New, refurbished or used. Tell us the quantity and condition and we connect you with a vetted reseller in your region, usually within one working day.
Sources
- Juniper QFX5120-48T Product Overview, checked 2026-10-27
- Juniper QFX5120-48T Datasheet, checked 2026-10-27