Juniper QFX5120 Comparison Guide & Battle Cards
Last updated: September 2026. This guide was reviewed against Juniper’s QFX5120 hardware documentation and corrected. Earlier versions described a “QFX5120-64C” model and a “mixed-media” QFX5120-48YM; neither is accurate (there is no QFX5120-64C, and the 48YM is the MACsec-on-all-ports version of the 48Y). Port counts, MACsec support, and Virtual Chassis limits below are taken from Juniper’s documentation. Juniper Networks became part of HPE on July 2, 2025; the QFX line continues under the Juniper name.
This guide covers the Juniper QFX5120 series model by model, compares it with the other QFX5100-family platforms (QFX5100, QFX5110, QFX5200, QFX5210, QFX5220, QFX5130) and with the EX4650, and then maps each QFX5120 model to the closest equivalents from Cisco, Arista, Dell, Extreme, and HPE Aruba so you can compare like with like.
Table of Contents
- QFX5120 Model Family Breakdown
- QFX5120 vs QFX5100, QFX5110, QFX5200, QFX5210, QFX5220, QFX5130
- QFX5120 vs EX4650
- Competitive Equivalents by Vendor
- Where the QFX5120 Fits Best
- Buying Refurbished QFX5120 from BrightStar Systems
- Frequently Asked Questions
Juniper QFX5120 Series – Model Family Breakdown
The QFX5120 is Juniper’s mainstream 25GbE/100GbE fixed-configuration data center switch family, running Junos OS and positioned for leaf, spine, and collapsed-core roles in EVPN-VXLAN fabrics, as well as campus core and aggregation. There are four models. All are 1RU with redundant, field-replaceable power supplies and fan modules, and each is sold in front-to-back (AFO, airflow out) and back-to-front (AFI, airflow in) airflow versions with AC or DC power.
| Model | Front-panel ports | Throughput (bidirectional) | MACsec | Virtual Chassis | Typical role |
|---|---|---|---|---|---|
| QFX5120-48Y | 48 x 1/10/25GbE SFP28 + 8 x 40/100GbE QSFP28 | 4 Tbps | No | Up to 2 members | 25GbE server leaf, campus core |
| QFX5120-48YM | 48 x 1/10/25GbE SFP28 + 8 x 40/100GbE QSFP28 | 4 Tbps | Yes, all ports (IEEE 802.1AE) | Up to 4 members | 25GbE leaf where link encryption is required |
| QFX5120-48T | 48 x 1/10GbE BASE-T (RJ-45) + 6 x 40/100GbE QSFP28 | 2.16 Tbps | No | Up to 2 members | 10GBASE-T server or campus access |
| QFX5120-32C | 32 x 40/100GbE QSFP28 + 2 x 10GbE SFP+ | 6.4 Tbps | No | Up to 2 members | 100GbE spine, aggregation, collapsed core |
Source: Juniper QFX5120 hardware documentation (system overview). Virtual Chassis support was introduced in Junos OS 19.3R1 (48Y), 20.2R1 (48T), 20.3R1 (32C), and 23.1R1 (48YM). The QFX5120 supports Virtual Chassis but not Virtual Chassis Fabric (VCF); VCF is a QFX5100/QFX5110-era feature.
QFX5120-48Y (1/10/25GbE Access with 100GbE Uplinks)
The QFX5120-48Y is the volume model of the family: 48 SFP28 ports that run at 1, 10, or 25GbE depending on the optic, plus eight QSFP28 ports at 40 or 100GbE. Each QSFP28 port can be broken out to 4 x 25GbE or 4 x 10GbE. It is the standard top-of-rack leaf for 25GbE servers in EVPN-VXLAN fabrics and a common campus core or aggregation switch.
Ordering variants: QFX5120-48Y-AFO and -AFI (first-generation fan modules), QFX5120-48Y-AFO2 and -AFI2 (second-generation fan modules), each with AC or DC power. The -T suffix on Juniper SKUs denotes TAA-compliant units. BrightStar Systems carries the QFX5120-48Y-AFO, QFX5120-48Y-AFO2, QFX5120-48Y-AFI, and QFX5120-48Y-AFI2.
Strengths: 25GbE density with eight 100GbE uplinks (1.5:1 oversubscription at full 25GbE load), full EVPN-VXLAN and MPLS feature set in Junos, low latency. Limits: no MACsec (see the 48YM), and 100GbE port count is limited to the eight uplinks, so it is not a spine platform.
QFX5120-48YM (Same Layout, MACsec on Every Port)
The QFX5120-48YM has the same 48 x SFP28 + 8 x QSFP28 layout and 4 Tbps throughput as the 48Y, with one difference that matters: IEEE 802.1AE MACsec is supported on all 56 ports. It also supports Virtual Chassis of up to four members (the 48Y supports two) and uses 850 W power supplies rather than the 650 W units in the 48Y. Choose the 48YM when the design calls for line-rate encryption on server or inter-switch links, for example in regulated environments or for DCI over leased fiber.
Ordering variants: QFX5120-48YM-AFO and -AFI, AC or DC. Earlier versions of this guide described the 48YM as a mixed copper/fiber switch with 200GbE QSFP56 uplinks; that was incorrect.
QFX5120-48T (10GBASE-T Copper Access)
The QFX5120-48T provides 48 RJ-45 ports at 1 or 10GbE for environments cabled with Cat6/Cat6A copper, plus six QSFP28 ports at 40 or 100GbE for uplinks (each breakout-capable to 4 x 25GbE or 4 x 10GbE). It is the choice for 10GBASE-T server racks and for campus cores and server rooms that are not moving to fiber yet. Throughput is 2.16 Tbps.
Ordering variants: QFX5120-48T-AFO and -AFI with 650 W AC or DC or 850 W high-voltage power supplies. BrightStar Systems carries the QFX5120-48T-AFO and QFX5120-48T-AFI.
Strengths: reuses existing copper cabling, same Junos feature set as the fiber models. Limits: 10GBASE-T draws more power and adds more latency per port than SFP+ optics or DACs, and there is no 25GbE option on copper.
QFX5120-32C (100GbE Spine and Aggregation)
The QFX5120-32C is the 100GbE member of the family: 32 QSFP28 ports at 40 or 100GbE plus two SFP+ 10GbE ports, with 6.4 Tbps of throughput. Each QSFP28 port breaks out to 4 x 25GbE or 4 x 10GbE, which lets the 32C serve as a spine for QFX5120-48Y leaves, as a collapsed core in smaller fabrics, or as a high-density 25GbE leaf via breakout.
Ordering variants: QFX5120-32C-AFO and -AFI, AC or DC. BrightStar Systems carries the QFX5120-32C-AFO and QFX5120-32C-AFI.
Strengths: 32 x 100GbE in 1RU, breakout flexibility, the same Junos image as the leaf models. Limits: no native 25GbE server ports and no MACsec; for 400GbE spines see the QFX5220 and QFX5130 below.
QFX5120 vs QFX5100, QFX5110, QFX5200, QFX5210, QFX5220, and QFX5130
The QFX5120 sits in the middle of Juniper’s fixed-configuration QFX5000 line. The generations differ mainly in port speed and density; all run Junos OS with EVPN-VXLAN.
| Platform | Representative models and ports | Generation / position |
|---|---|---|
| QFX5100 | QFX5100-48S: 48 x 10GbE SFP+ + 6 x 40GbE QSFP+; QFX5100-48T (10GBASE-T); QFX5100-24Q (24 x 40GbE); QFX5100-96S (96 x 10GbE + 8 x 40GbE) | 10/40GbE generation. Juniper has published end-of-life milestones for QFX5100 models (for example, QFX5100-96S: last order date December 31, 2022, end of support December 31, 2027); see our Juniper end of life list. Widely available refurbished at low cost. |
| QFX5110 | QFX5110-48S: 48 x 10GbE SFP+ + 4 x 100GbE QSFP28; QFX5110-32Q: 32 x 40GbE QSFP+ (100GbE-capable on a subset) | 10GbE access with 100GbE uplinks; the bridge between QFX5100 and QFX5120. |
| QFX5120 | 48Y / 48YM / 48T / 32C as described above | 25GbE access and 100GbE spine; current mainstream platform. |
| QFX5200 | QFX5200-32C: 32 x 100GbE QSFP28; QFX5200-48Y: 48 x 25GbE + 6 x 100GbE | Earlier 100GbE spine/leaf platform, contemporary with QFX5110; still common on the secondary market. |
| QFX5210 | QFX5210-64C: 64 x 100GbE QSFP28 | High-density 100GbE spine (this is the 64-port 100GbE model sometimes misattributed to the QFX5120 family). |
| QFX5220 | QFX5220-32CD: 32 x 400GbE QSFP56-DD; QFX5220-128C: 128 x 100GbE | 400GbE spine generation. |
| QFX5130 | QFX5130-32CD: 32 x 400GbE QSFP56-DD + 2 x 10GbE | 400GbE leaf/spine with larger tables and richer feature set than the QFX5220. |
For a closer look at the 10/40GbE generations, see our QFX5100 vs QFX5110 vs QFX5200 comparison. Practical guidance: choose QFX5120 when servers are 25GbE or you need 100GbE uplinks and a current platform; choose QFX5100 or QFX5110 for 10GbE racks where cost matters more than headroom; choose QFX5220 or QFX5130 when the spine or the servers are 400GbE.
QFX5120 vs EX4650
The EX4650-48Y shares the QFX5120-48Y’s physical layout (48 x 1/10/25GbE SFP28 + 8 x 100GbE QSFP28) and hardware platform, but it is positioned and licensed as an enterprise campus core and aggregation switch under the EX Series, with EX-style Virtual Chassis and campus feature licensing. The QFX5120-48Y is positioned for data center EVPN-VXLAN fabrics with the data center feature set. If the design is a campus core, the EX4650 is usually the right SKU; if it is a data center leaf or a collapsed core running EVPN-VXLAN, the QFX5120-48Y is. Our QFX vs EX guide covers the positioning in more depth.
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Competitive Equivalents by Vendor
The tables below map each QFX5120 model to the closest equivalent from other vendors by port layout. They are intended to help you compare like with like when a design is not vendor-locked; the right choice usually turns on the operating system your team runs, the fabric model, licensing, and price rather than on hardware differences, which are small at this tier.
Cisco
| QFX5120 model | Closest Cisco equivalent | Ports | Notes |
|---|---|---|---|
| QFX5120-48Y | Nexus 93180YC-FX | 48 x 1/10/25GbE + 6 x 40/100GbE | Two fewer 100GbE uplinks than the 48Y; NX-OS or ACI mode. |
| QFX5120-48Y | Nexus 93240YC-FX2 | 48 x 1/10/25GbE + 12 x 40/100GbE | More 100GbE uplinks; 1.2RU form factor. |
| QFX5120-48T | Nexus 93108TC-FX | 48 x 100M/1/10GBASE-T + 6 x 40/100GbE | Direct copper equivalent. |
| QFX5120-32C | Nexus 9336C-FX2 | 36 x 40/100GbE | Four more 100GbE ports; common ACI/NX-OS spine. |
| QFX5120-48Y / 48YM (campus core) | Catalyst 9500-48Y4C | 48 x 1/10/25GbE + 4 x 40/100GbE | Campus-positioned with MACsec; compare with the EX4650 as much as the QFX5120. |
See our Cisco Nexus 9000 inventory and Catalyst 9000 inventory.
Arista
| QFX5120 model | Closest Arista equivalent | Ports | Notes |
|---|---|---|---|
| QFX5120-48Y | 7050SX3-48YC8 | 48 x 1/10/25GbE + 8 x 40/100GbE | Port-for-port equivalent; the 7050SX3-48YC12 adds four more 100GbE ports. See our Arista 7050 series guide. |
| QFX5120-48T | 7050TX3-48C8 | 48 x 100M/1/10GBASE-T + 8 x 40/100GbE | Two more 100GbE uplinks than the 48T. |
| QFX5120-32C | 7050CX3-32S | 32 x 40/100GbE + 2 x 10GbE SFP+ | Port-for-port equivalent, including the two SFP+ ports. |
| QFX5120-32C (deep-buffer alternative) | 7280CR3-32D4 / 7280CR3K-32P4 | 32 x 100GbE + 4 x 400GbE | Different class: deep packet buffers and internet-scale routing tables at a higher price. See our 7280R guide. |
See our Arista 7050X inventory and Juniper QFX5100 vs Arista 7050X comparison.
Dell, Extreme Networks, and HPE Aruba
| QFX5120 model | Equivalent | Ports | Notes |
|---|---|---|---|
| QFX5120-48Y | Dell PowerSwitch S5248F-ON | 48 x 25GbE + 4 x 100GbE + 2 x 200GbE | Open networking switch; runs Dell OS10 or SONiC. |
| QFX5120-32C | Dell PowerSwitch S5232F-ON | 32 x 100GbE + 2 x 10GbE | Open networking; OS10 or SONiC. |
| QFX5120-48Y | Extreme 7520-48Y-8C | 48 x 25GbE + 8 x 100GbE | Extreme’s Fabric Engine / Switch Engine platform. |
| QFX5120-32C | Extreme SLX 9240 | 32 x 100GbE | Older SLX-OS data center platform. |
| QFX5120-48Y | HPE Aruba CX 8325-48Y8C | 48 x 1/10/25GbE + 8 x 40/100GbE | Port-for-port equivalent on AOS-CX. Note that HPE now also owns Juniper. |
| QFX5120-32C | HPE Aruba CX 8325-32C | 32 x 40/100GbE | AOS-CX spine/aggregation. |
Where the QFX5120 Fits Best
- 25GbE server leaf in an EVPN-VXLAN fabric — QFX5120-48Y, with QFX5120-32C or a 400GbE QFX5220/QFX5130 as spine.
- Encrypted links — QFX5120-48YM is the only member with MACsec, and it has it on every port.
- 10GBASE-T racks or campus server rooms — QFX5120-48T.
- Collapsed core or small spine — QFX5120-32C, using breakout to serve 25GbE or 10GbE leaves.
- Campus core — QFX5120-48Y or, in most enterprise designs, the EX4650-48Y with the same layout.
- Automation-centric operations — all models run the same Junos OS with NETCONF, REST, and Ansible support and are managed by Juniper Apstra in fabric deployments.
Buying Refurbished QFX5120 from BrightStar Systems
BrightStar Systems specializes in refurbished Juniper and Arista data center equipment. Every QFX5120 we sell goes through our 9-Point Quality Control and Testing Process — inspection, serial verification, cleaning, power supply and fan testing, factory reset, testing of every physical port, a burn-in of at least one hour at operating temperature, and module verification — and ships with our 1-year in-house warranty for end users (90 days for resellers). Refurbished units are typically available at a large discount to list price, and we quote by exact model and airflow variant so the unit you receive matches the rack it is going into. Software licensing is not conveyed with used hardware; confirm your Junos licensing needs with Juniper or your reseller.
If you are retiring QFX5100, QFX5110, or QFX5120 equipment, we also buy it: see sell Juniper equipment.
Frequently Asked Questions
The Juniper QFX5120 is a series of high-performance, next-generation data center switches designed to handle large-scale, mission-critical workloads. It supports a variety of features like 25/100GbE ports, advanced automation, and programmability, providing the scalability, reliability, and flexibility needed for modern data centers and high-performance computing environments.
The QFX5120-48Y offers a high-speed networking solution with 48 ports of 1/10/25GbE (SFP28), along with eight 40/100GbE (QSFP28) uplink ports. This switch is designed for fast, scalable performance, making it ideal for environments that require high bandwidth and low latency.
The Juniper QFX5120 is known for its low latency, designed to meet the demands of modern data center networks. It offers a latency of less than 1 microsecond in optimal conditions, making it suitable for high-performance workloads where minimal delay is critical.
The QFX5120-48Y is a high-performance, fixed-configuration switch with 48 1/10/25GbE SFP28 ports and 8 40/100GbE QSFP28 uplink ports. It features a broad range of capabilities including support for low-latency networking, high availability, and network programmability. The QFX5120-48Y also offers full Layer 2 and Layer 3 support, making it an ideal choice for data center and high-performance networking environments.
The QFX and EX switches from Juniper are designed for different purposes. QFX switches are high-performance, data center-focused switches, ideal for large-scale networking environments, offering low latency and high throughput. EX switches, on the other hand, are optimized for enterprise and campus networks, providing reliable and cost-effective solutions for edge switching. While both series are part of Juniper’s portfolio, the QFX is typically used in more demanding, high-speed environments, whereas the EX series is better suited for general enterprise needs.
The QFX5120 is ideal for high-performance computing, cloud workloads, and modern data center environments where fast, scalable networking is critical. It supports high-density configurations and offers 25GbE and 100GbE ports, making it suitable for demanding applications such as virtualization, big data analytics, and large-scale cloud services.
No, the QFX5120 does not support Power over Ethernet (PoE). It is designed primarily for high-speed data center and cloud workloads, focusing on high-performance connectivity with 25GbE and 100GbE ports, rather than powering devices over Ethernet.
While the QFX5120 is more suited for core and aggregation layers in large data centers, it can also be leveraged in edge computing environments where high-speed, low-latency networking is essential. However, for smaller, less demanding edge deployments, switches like the QFX5100 might be a more cost-effective choice.
The QFX5120 can deliver up to 100GbE of throughput per port, supporting a range of high-bandwidth applications in large-scale environments. Its high-speed ports enable it to handle the data demands of modern cloud and data center workloads efficiently.
The QFX5120 is designed with energy efficiency in mind, using advanced hardware and software optimizations to reduce power consumption while maintaining high performance. Compared to other Juniper switches like the QFX5100 or QFX5200, the QFX5120 offers more power-efficient operations, especially at higher port densities, helping reduce the total cost of ownership.
The QFX5120 and EX4650 are both high-performance switches, but they are designed for different use cases. The QFX5120 is tailored for data center environments, offering low latency, high throughput, and scalability with features like 25GbE and 100GbE ports. It is ideal for high-density, high-performance network applications. On the other hand, the EX4650 is designed for enterprise and campus networks, offering flexibility, scalability, and security for edge deployments, with support for 1GbE, 10GbE, and 25GbE. While both are powerful, the QFX5120 is more suited for the data center, while the EX4650 is better for the enterprise network edge.
The QFX5120 and QFX5200 are both part of Juniper’s QFX series, but they differ in their target applications and performance capabilities. The QFX5120 is a newer model with a focus on high-density, high-speed data center deployments, supporting 25GbE and 100GbE ports, and offering low latency and high scalability. The QFX5200, while also suitable for data center environments, offers a wider range of port options, including 10GbE, 25GbE, and 100GbE, and is typically used for mid-tier data center applications. The QFX5120 is more modern with better optimization for cloud and high-performance computing workloads.
The QFX5120 and QFX5110 are both part of Juniper’s QFX family but serve different roles in a network. The QFX5120 offers more advanced capabilities, including 25GbE and 100GbE ports, optimized for high-density data center environments requiring ultra-low latency. In contrast, the QFX5110 is a more entry-level switch with 10GbE and 40GbE support, typically used for smaller-scale deployments or edge networking. The QFX5120 offers higher throughput, better scalability, and a more modern feature set, while the QFX5110 is a cost-effective option for less demanding environments.
The QFX5120 and QFX5100 are both part of the same QFX series, but they cater to different needs within a network. The QFX5120 offers more advanced features, including 25GbE and 100GbE ports, designed for high-performance, high-density data centers, and cloud-based applications. The QFX5100, while still a high-performing switch, is generally used for mid-sized data center deployments, offering support for 10GbE and 40GbE ports. The QFX5120 provides better scalability, enhanced programmability, and more robust performance compared to the QFX5100, making it the preferred choice for demanding environments.