The Juniper QFX5120 Series delivers high-performance 25GbE and 100GbE switching built on the Broadcom Trident 3 ASIC, designed for modern EVPN-VXLAN leaf/spine fabrics, data center edge, and high-density cloud architectures. BrightStar Systems supplies fully tested, used and refurbished QFX5120 switches backed by our 1-Year In-House Warranty, helping you scale your fabric at a fraction of new hardware cost.
The Juniper QFX5120 Series delivers high-performance 25GbE and 100GbE switching built on the Broadcom Trident 3 ASIC, designed for modern EVPN-VXLAN leaf/spine fabrics, data center edge, and high-density cloud architectures. BrightStar Systems supplies fully tested, used and refurbished QFX5120 switches backed by our 1-Year In-House Warranty, helping you scale your fabric at a fraction of new hardware cost.[readmore]
With flexible airflow (AFO/AFI), 1/10/25GbE access, 40/100GbE uplinks, and deep automation support under Junos OS, the QFX5120 Series is a proven platform for data center leaf roles, high-performance top-of-rack (ToR), or 100GbE aggregation.
Juniper QFX5120 Series Overview
The QFX5120 family is built for performance-sensitive data centers and scalable EVPN-VXLAN deployments. Based on the Broadcom Trident 3 chipset, QFX5120 switches deliver low latency, large forwarding tables, dynamic buffer allocation, and support for automation frameworks such as Ansible, ZTP, and PyEZ.
Key features of the QFX5120 Series include:
48 × 1/10/25GbE SFP28 access ports on “48Y” models
48 × 10GBASE-T copper access ports on “48T” models
32 × 40/100GbE QSFP28 ports on “32C” spine/aggregation models
Airflow-out (AFO) and airflow-in (AFI) variants to match hot/cold aisle designs
EVPN-VXLAN features for multitenant cloud fabrics
Broadcom Trident 3 ASIC for low-latency, non-blocking forwarding
1RU compact form factors for dense data center deployments
For multigig campus access, consider the EX4400 Series, or explore higher-capacity ToR/leaf options in the broader Juniper QFX Series.
Explore More Juniper Switches
The QFX5120 Series slots into the broader Juniper QFX and EX portfolio and is commonly deployed alongside higher-scale QFX leaf/spine platforms or MX core routers.
All Juniper EX Series Switches
Juniper QFX Series (Data Center)
Juniper MX Series Routers
Juniper SRX Firewalls
Related Juniper & Arista Switch Families
BrightStar Systems supplies both Juniper and Arista data center switches. Many customers compare QFX5120 leaf switches against Arista 7000-series ToR platforms.
Arista 7050X Series – 10/40GbE ToR and campus aggregation
Arista 7060X Series – High-density 25/100GbE leaf/spine
Arista 7280 Series – Deep buffer and routing-optimized models
Popular Juniper QFX5120 Models
Below are some of the most frequently purchased QFX5120 switches from BrightStar Systems. All units are fully tested and covered by our 1-Year In-House Warranty.
QFX5120-48Y-AFO
– 48× 1/10/25GbE SFP28 + 8× 100GbE QSFP28, airflow-out, ideal for 25GbE EVPN leaf roles with 100GbE uplinks.
QFX5120-48Y-AFI
– 48× 1/10/25GbE SFP28 + 8× 100GbE QSFP28, airflow-in, for cold-aisle intake in hot/cold aisle designs.
QFX5120-48Y-AFO2
– Updated 25GbE/100GbE AFO variant for dense, automated leaf fabrics.
QFX5120-48Y-AFI2
– Updated AFI model with 48× 1/10/25GbE access ports and 8× 100GbE uplinks.
QFX5120-48T-AFO
– 48× 10GBASE-T + 6× 100GbE, airflow-out, ideal for copper-heavy racks migrating to 100GbE core.
QFX5120-48T-AFI
– 48× 10GBASE-T + 6× 100GbE, airflow-in, for data centers standardized on PSUs-in airflow.
QFX5120-32C-AFO
– 32× 40/100GbE QSFP28, airflow-out, compact 100GbE spine or aggregation switch.
QFX5120-32C-AFI
– 32× 40/100GbE QSFP28, airflow-in, for spine/aggregation roles in reversed-flow racks.
Juniper QFX5120 Architecture & Technical Specs
QFX5120 switches deliver wire-rate Layer 2/3 forwarding with a deep EVPN-VXLAN feature set. The Broadcom Trident 3 ASIC provides high-radix switching, cut-through forwarding, and dynamic buffer allocation for bursty east-west traffic patterns in leaf/spine designs.
ASIC: Broadcom Trident 3
Access ports: 48× 1/10/25GbE SFP28 (48Y) or 48× 10GBASE-T (48T)
Uplinks: 40/100GbE QSFP28 (8× on 48Y, 6× on 48T, 32× on 32C)
Forwarding: Low-latency, non-blocking architecture across access and uplinks
EVPN-VXLAN: Supported for L2/L3 overlays, multi-tenant fabrics, and seamless L2 extension
Automation: ZTP, Ansible, PyEZ, NETCONF, and scripting via Junos OS
Airflow: AFO (port-to-PSU) and AFI (PSU-to-port) models to match existing hot/cold aisle standards
Common Juniper QFX5120 Use Cases
EVPN-VXLAN leaf switches for 25GbE-attached servers with 100GbE uplinks
Top-of-rack (ToR) in dense compute racks using 48Y or 48T models
100GbE aggregation/spine using 32C models in smaller fabrics
Hybrid copper/fiber environments where 10GBASE-T and SFP28 coexist
Automated data centers leveraging ZTP and configuration management tooling
Compatible Optics & Cables
QFX5120 switches support a wide range of optics for short-reach and long-reach connectivity.
Juniper SFP+/SFP28/QSFP+/QSFP28 optics & cables
25GbE SFP28 SR/LR for leaf-to-spine links or server connections
100GbE QSFP28 SR4/LR4/PSM4/CWDM4 for fabric and DCI connectivity
DAC/AOC cables for short-reach ToR and spine links
Why Buy Used or Refurbished QFX5120 Switches?
Buying used QFX5120 switches from BrightStar Systems can reduce project costs without sacrificing reliability.
40–80% savings versus new Juniper list pricing
Faster lead times than many OEM channels
Fully tested, cleaned, and reset to factory defaults
Backed by our 1-Year In-House Warranty
QFX5120 Buy-Back & Trade-In Options
If you are decommissioning QFX5120 switches, BrightStar Systems can help you recover value and simplify asset disposition.
Fast bids on surplus QFX5120 and related Juniper hardware
Support for full rack or site decommissioning projects
Option to trade in QFX5120 inventory toward newer QFX or MX platforms
Contact our team with an inventory list to get a buy-back or trade-in quote.
Expertise from Juniper-Focused Network Engineers
BrightStar Systems is more than a hardware broker. Our team works with Juniper EX, QFX, and MX platforms every day in real data center and campus designs.
Experience designing QFX5120 deployments as data center leaf, ToR, and spine nodes
Guidance on EVPN-VXLAN fabric design, underlay routing, and QFX integration with MX cores
Assistance matching optics, power supplies, and airflow SKUs to your existing standards
If you have questions about how QFX5120 will fit into your architecture, our engineers can walk through the design with you before you buy.
FAQ – Juniper QFX5120 Series
Q: Is the QFX5120 a good fit for EVPN-VXLAN?
Yes. QFX5120 switches are commonly deployed as 25GbE/100GbE EVPN leaf nodes with full VXLAN support and integration with MX or higher-end QFX spines.
Q: What ASIC does the QFX5120 use?
All QFX5120 models are based on the Broadcom Trident 3 ASIC, providing low-latency, non-blocking forwarding with flexible buffering.
Q: Which airflow options are available?
Most QFX5120 models are available in AFO (port-to-PSU) and AFI (PSU-to-port) variants. Matching airflow to your existing hot/cold aisle design is critical, and we can help confirm the correct SKUs.
Q: Do you buy used QFX5120 switches?
Yes. BrightStar Systems actively buys used QFX5120 switches and related Juniper hardware. We can provide bids on individual units or full decommissioning projects.
Q: Can QFX5120 be used as a spine?
Yes. The QFX5120-32C models are frequently used as compact 100GbE spines or aggregation switches in small to mid-sized fabrics.
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