Juniper QFX switches are 1U top-of-rack and spine switches for the data center, with 10GbE, 25GbE and 100GbE ports. They also run Junos OS, so they suit everything from a single server rack to a full leaf and spine fabric.
Still, choosing one comes down to two things: port speed and airflow. This guide compares the QFX5110, QFX5120 and QFX5200, plus the EX4600 and EX4650, and it explains AFO vs AFI so your new switch suits your hot and cold aisles.
Where Juniper QFX switches fit
When you build a leaf and spine design, top-of-rack leaf switches connect servers and storage. Then spine switches tie the leaf switches together. QFX models cover both roles, so the choice depends on port speed and density.
The EX4600 and EX4650 also belong in this tier. Although they carry the EX name, they work as aggregation and top-of-rack switches with 10GbE and 25GbE ports. So we group them with QFX in this guide.
10G options: QFX5110 and EX4600
The QFX5110-48S has 48 10GbE SFP+ ports and 4 QSFP28 ports for 100GbE, 40GbE or 4x10GbE breakout. It also moves up to 960 Gbps, so it suits 10G server racks with 100G uplinks. Juniper sells it in AFO and AFI versions, such as the QFX5110-48S-AFO and QFX5110-48S-AFI.
The EX4600-40F-AFO is another 10GbE option, especially for aggregation. It has 24 SFP+ ports, 4 40GbE QSFP+ ports and 2 expansion slots for extra QSFP+ or SFP+ modules. In addition, it ships with two 650 W AC power supplies.
25G Juniper QFX switches: QFX5120-48Y and EX4650
When servers move to 25G, the QFX5120-48Y is the common choice. It has 48 SFP28 ports at 25, 10 or 1GbE and 8 QSFP28 ports at 100 or 40GbE, with 4 Tbps of throughput. Similarly, the EX4650-48Y-AFO offers 48 SFP28 ports and 8 QSFP28 ports at 4 Tbps.
Because the QFX5120-48Y comes in several SKUs, read the suffix carefully. We cover AFO vs AFO2 in the airflow section below.
100G options: QFX5120-32C and QFX5200
For spine or 100G top-of-rack roles, look at 32-port models instead. The QFX5120-32C-AFO has 32 100/40GbE QSFP28 ports plus 2 10GbE SFP+ ports, with 6.4 Tbps of throughput. Meanwhile, the QFX5200-32C has 32 QSFP28 ports that run at 100GbE by default.
The QFX5200-32C can also run each port at 50, 40, 25 or 10GbE, including 4x25G and 4x10G breakout. As a result, one QFX5200 can serve a mix of 100G and 25G links. It comes as the QFX5200-32C-AFO or QFX5200-32C-AFI, so pick the airflow that suits your rack.
AFO vs AFI airflow for Juniper QFX switches
Airflow causes more ordering mistakes than anything else on data center switches. AFO means Air Flow Out, so air moves front to back, from the port side to the power supply and fan side. AFI means Air Flow In, so air moves back to front, from the FRU side to the port side.
Before you choose, look at which way the ports face in your rack. When the ports face the cold aisle, you need AFO. However, if the ports face the hot aisle, you need AFI.
Juniper does not support mixing airflow directions in one chassis. So fans and power supplies must match the switch, and every switch in a row should follow the same plan.
What about AFO2 and AFI2?
Juniper's current listing for the QFX5120-48Y names only the AFO2 and AFI2 models. However, Juniper does not explain the "2" suffix in its documentation. Still, the practical point is simple: the QFX5120-48Y-AFO2 is the current front-to-back model, while the QFX5120-48Y-AFO and QFX5120-48Y-AFI are earlier SKUs.
Overall, all of them share the same 48 SFP28 and 8 QSFP28 port layout. So if you are adding to an existing rack, send us the exact SKU from the label, and we will match it.
Juniper QFX switches part numbers we supply
Silverback supplies every model below in new or used condition. So send us the part number, and get pricing and lead time within one business day.
| Part number | Product | Notes |
|---|---|---|
| EX4600-40F-AFO | EX4600 10GbE switch, front-to-back airflow | 24x SFP+, 4x 40GbE QSFP+, 2 expansion slots |
| EX4650-48Y-AFO | EX4650 25GbE switch, front-to-back airflow | 48x SFP28, 8x 100GbE QSFP28, 4 Tbps |
| QFX5110-48S | QFX5110-48S 10GbE data center switch | 48x SFP+, 4x QSFP28, 960 Gbps |
| QFX5110-48S-AFO | QFX5110-48S, AC, front-to-back airflow | 48x 10GbE SFP+, 4x 100GbE QSFP28 |
| QFX5110-48S-AFI | QFX5110-48S, AC, back-to-front airflow | 48x 10GbE SFP+, 4x 100GbE QSFP28 |
| QFX5120-48Y | QFX5120-48Y 25GbE data center switch | 48x SFP28, 8x QSFP28, 4 Tbps |
| QFX5120-48Y-AFO | QFX5120-48Y, AC, front-to-back airflow | Original SKU; current listing names the AFO2 |
| QFX5120-48Y-AFO2 | QFX5120-48Y, AC, front-to-back airflow | Current SKU, 650 W power supplies |
| QFX5120-48Y-AFI | QFX5120-48Y, AC, back-to-front airflow | Earlier SKU; current listing names the AFI2 |
| QFX5120-32C-AFO | QFX5120-32C 100GbE switch, front-to-back airflow | 32x QSFP28, 2x SFP+, 6.4 Tbps |
| QFX5200-32C | QFX5200-32C 100GbE data center switch | 32x QSFP28, 100/50/40/25/10GbE |
| QFX5200-32C-AFO | QFX5200-32C, AC, front-to-back airflow | 32x 100GbE QSFP28 |
| QFX5200-32C-AFI | QFX5200-32C, AC, back-to-front airflow | 32x 100GbE QSFP28, two AC PSUs |
New vs used data center switches
Data center switches often come out of service after a refresh while they still have years of life left. As a result, used units make a smart buy. For example, a used QFX5110-48S can add 10G ports to an older pod for far less than new.
Still, new hardware makes sense when you need a long support runway. Silverback supplies new and used QFX and EX data center switches, tested before they ship. For a deeper comparison, read refurbished vs new enterprise hardware.
Why buy Juniper QFX switches from Silverback
When you retire a pod, Silverback buys back the switches and offers certified data destruction under R2v3, ISO 14001 and ISO 45001. Our data center decommissioning checklist also helps you plan the move.
Silverback is a trusted supplier of Juniper hardware and a certified HPE Business Partner. In fact, Juniper now sits within HPE Networking. See our Juniper buyer's guide for the full range, or our EX access switch guide for campus models.
Of course, full specs live on juniper.net. Meanwhile, you can browse our inventory or request pricing for any part number above.
Frequently Asked Questions
What does AFO mean on a Juniper switch?
AFO means Air Flow Out, or front-to-back airflow, from the port side to the power supply and fan side. AFI is the reverse, so air moves back to front.
Is the QFX5120-48Y-AFO2 the same as the QFX5120-48Y-AFO?
Both are AC, front-to-back airflow models with 48 SFP28 and 8 QSFP28 ports. The AFO2 is the current SKU in Juniper's listing, while the AFO is the earlier one.
Which switch should I use for 25G servers?
The QFX5120-48Y fits most 25G racks, with 48 SFP28 ports and 8 QSFP28 uplinks. The EX4650-48Y-AFO offers a similar port layout.
Can I mix AFO and AFI parts in one switch?
No. Juniper does not support mixing airflow directions in one chassis, so fans and power supplies must match.
Do you sell used QFX switches?
Yes. Silverback supplies new and used QFX switches, tested before they ship. Ask for new or used condition when you request a quote.
Get a quote for Juniper QFX switches
Whether you need a single QFX5120-48Y-AFO2 or a full set of spine switches, Silverback can help. Send us your part list with the airflow you need, and we will reply with pricing and lead time within one business day.
Then call (888) 391-5211 or get a free quote online. Ask for new or used condition, and we will match every SKU to your racks.
