Juniper QFX5120-48Y-AFI2 | 48x25G + 8x100G Switch

Juniper QFX5120-48Y-AFI2 — Used & Refurbished 25GbE Top-of-Rack Switch

The Juniper QFX5120-48Y-AFI2 is a high-performance 1U data center switch offering 48 × 1/10/25GbE SFP28 access ports and 8 × 40/100GbE QSFP28 uplinks. This AFI2 airflow variant provides port-side intake airflow (AFI), making it ideal for data center cold-aisle cooling designs and environments requiring front-to-back intake.

BrightStar Systems supplies fully tested, used and refurbished QFX5120-48Y-AFI2 switches, ensuring reliability for high-density server access, EVPN-VXLAN fabrics, and scalable leaf-spine architectures.

Juniper QFX5120-48Y-AFI2 Overview

The QFX5120-48Y-AFI2 operates as part of Juniper’s high-performance QFX5120 switching family and is purpose-built for modern Layer 2/Layer 3 fabrics and virtualized workloads. It provides consistent low-latency forwarding, wide automation support, and the throughput necessary for cloud-scale east–west traffic patterns.

• 48 × SFP28 access ports supporting 1/10/25GbE
• 8 × QSFP+/QSFP28 uplink ports supporting 40GbE and 100GbE
• AFI airflow (port-side intake) for cold-aisle alignment
• Optimized for EVPN-VXLAN overlays and scalable leaf-spine fabrics
• Flexible automation via Junos OS, NETCONF, REST, Python, and Ansible
• Redundant, hot-swappable fans and power supplies

Technical Specifications

• Model: QFX5120-48Y-AFI2
• Port Configuration: 48 × 1/10/25GbE SFP28 + 8 × 40/100GbE QSFP28
• Form Factor: 1U fixed-configuration switch
• Airflow: AFI (port-side intake)
• Features: EVPN-VXLAN, L2/L3 switching, QoS, telemetry, automation
• OS: Junos OS
• Redundancy: Hot-swappable PSUs and fan modules

Common Use Cases

• 25GbE leaf switches in EVPN-VXLAN fabrics
• High-density virtualized environments requiring predictable throughput
• Cloud-scale deployments transitioning from 10GbE to 25GbE
• Enterprises and service providers standardizing on Juniper QFX
• Data centers requiring AFI airflow for hot/cold aisle alignment

Why Choose the QFX5120-48Y-AFI2?

The QFX5120-48Y-AFI2 delivers high port density, flexible deployment options, and advanced overlay capabilities. Organizations with cold-aisle intake requirements benefit from the AFI airflow design while retaining the high-performance feature set of the QFX5120 family.

QFX5120 Series Comparison & Resources

• QFX5120 Series Comparison Guide
• Juniper QFX vs EX Series Comparison

Other QFX5120 Models We Stock

• QFX5120-48Y-AFO
• QFX5120-48Y-AFO2
• QFX5120-48Y-AFI
• QFX5120-32C-AFO
• QFX5120-32C-AFI

• Model: QFX5120-48Y-AFI
• Device Type: Switch – 48 ports – L3 – managed – stackable
• Enclosure Type: Back-to-front airflow rack-mountable 1U
• Subtype 25 Gigabit Ethernet
• Ports: 48 x 1/10/25 Gigabit SFP28 + 8 x 40/100 Gigabit QSFP28
• Performance Switching capacity: 2 Tbps ¦ Switching capacity: 1.31 Apps
• Capacity: Virtual interfaces (VLANs): 4093 ¦ VLAN Spanning Tree Protocol instances: 509 ¦ Multiple Spanning Tree Protocol instances:
• 64 ¦ ARP entries: 64000 ¦ Link aggregation groups: 80 ¦ Maximum member ports per LAG: 64 ¦ IPv4 prefixes (Unicast): 351000 ¦ IPv4 hosts: 208000 ¦ IPv4 routes (Multicast): 104000 ¦ ECMP paths: 64 ¦ IPv6 prefixes (Unicast): 168000 ¦ IPv6 hosts: 104000 ¦ IPv6 routes
• (Multicast): 52000 ¦ Mirroring destination ports per switch: 4 ¦ Maximum number of mirroring sessions: 4 ¦ Mirroring destination VLANs per switch: 4 ¦ Queues per port: 10
• MAC Address Table Size: 288K entries
• Jumbo Frame Support: 9216 bytes
• Routing Protocol: OSPF, RIP, IS-IS, RIP-1, RIP-2, BGP, IGMPv2, IGMP, VRRP, OSPFv2, PIM-SM, PIM-DM, IGMPv3, PIM-SSM, MSDP, static IPv4 routing, static IPv6 routing, MPLS, Bidirectional Forwarding Detection (BFD), CIDR, RSVP
• Remote Management Protocol: SNMP 1, SNMP 2, RMON, Telnet, SNMP 3, HTTP, SSH, SSH-2, CLI, OVSDB
• Encryption Algorithm: MD5
• Authentication Method: RADIUS, TACACS+, Secure Shell v.2 (SSH2)

• 1-Year BrightStar warranty for end user customers
• 90-Day BrightStar Warranty for resellers

• Free FedEx Ground shipping within the United States
• FedEx Overnight shipping available as well
• FedEx International Shipping available for customers outside of the United States

Q1: What is the primary difference between the QFX5120-48Y-AFI and the AFI2 model?
A1: The AFI2 model features an updated Airflow In (AFI2) design, ideal for specific airflow configurations in data centers requiring front-to-back cooling.

Q2: How many uplinks are available on this switch?
A2: The QFX5120-48Y-AFI2 provides 6 x 100GbE QSFP28 uplink ports, offering high-speed connectivity and flexible networking options.

Q3: Can this switch handle high-performance and low-latency applications?
A3: Yes, with ultra-low latency and a 3.6 Tbps switching capacity, this switch is perfect for real-time applications requiring high performance, such as cloud computing, virtualization, and financial services.

Q4: Is this switch energy-efficient?
A4: Absolutely. The QFX5120-48Y-AFI2 is designed for energy efficiency, helping to reduce power consumption and lower operational costs in data centers.

Q5: Does the switch support network stacking?
A5: Yes, it supports Juniper’s Virtual Chassis technology, which allows multiple switches to operate as a single logical device, simplifying network management and scaling.