The Cisco C9500-24Y4C-A vs C9500-48Y4C-A decision is mainly a question of port density, expansion risk, and project scale. Both models belong to the Catalyst 9500 high-performance family and use four fixed 40/100G uplink ports. The C9500-24Y4C-A is the more compact option for smaller core or aggregation blocks, while the C9500-48Y4C-A is designed for higher-density deployments with more 1G, 10G, or 25G connections.
- Fixed QSFP28 uplink capacity and design implications
- High-density connections and future expansion
- Smaller deployments and controlled port requirements
- Matching port density to the network role
- Initial cost, expansion risk, and required quote information
- Common C9500-24Y4C-A and C9500-48Y4C-A questions
- A practical selection rule for the two models
C9500-24Y4C-A vs C9500-48Y4C-A Core Differences
The primary difference between the two models is the number of fixed 1G/10G/25G SFP28 ports. The C9500-24Y4C-A provides 24 ports, while the C9500-48Y4C-A provides 48 ports. Both models provide four fixed 40/100G QSFP28 uplinks.
| Platform | Downlink Ports | 100G Uplinks | Current Cisco Switching Capacity | Network License |
|---|---|---|---|---|
| C9500-24Y4C-A | 24 x 1G/10G/25G SFP28 | 4 x 40/100G QSFP28 | Up to 2.0 Tbps | Network Advantage |
| C9500-48Y4C-A | 48 x 1G/10G/25G SFP28 | 4 x 40/100G QSFP28 | Up to 3.2 Tbps | Network Advantage |
Cisco lists both models with 1G, 10G, and 25G port capability on the SFP28 interfaces. The current Cisco data sheet also lists four 40/100G ports for each model. Therefore, the 48Y4C-A is not a higher-uplink-count version of the 24Y4C-A; it is primarily the higher-density version.
The -A suffix identifies the Network Advantage hardware license tier for both models. It does not mean that the 48Y4C-A has a different port speed from the 24Y4C-A. Cisco software subscriptions or DNA term licenses are separate ordering considerations and should be checked against the current configuration and licensing requirements.
Are the 100G Uplinks the Same?
Yes. The C9500-24Y4C-A and C9500-48Y4C-A both provide four fixed QSFP28 uplink ports that support 40G or 100G operation, subject to the selected optics, cables, software, and connected-device configuration.
This means that moving from the 24Y4C-A to the 48Y4C-A does not automatically add more 100G uplinks. The upgrade gives the design twice the number of SFP28 downlink ports, while the uplink count remains four.
What This Means for Network Design
- Use the four uplinks for core interconnects, aggregation links, or other high-bandwidth northbound connections.
- Use the SFP28 ports for 1G, 10G, or 25G connections according to the deployment design.
- Do not select the 48Y4C-A solely because you need more 100G uplinks; both models have four.
- Check the required optics and interface configuration before finalizing the bill of materials.
For the official port-density table and platform details, review the Cisco Catalyst 9500 Series data sheet.
When Do You Need 48 25G Ports?
The C9500-48Y4C-A is the stronger fit when the design requires more than 24 active SFP28 connections or when replacing the switch later would be more disruptive than purchasing additional port capacity now.
Choose the 48Y4C-A When:
- The initial design needs 25 to 48 1G, 10G, or 25G connections.
- Several access switches, firewalls, servers, or aggregation devices will terminate on the same platform.
- The project expects additional 10G or 25G connections during the planned operating period.
- The network team wants spare ports for maintenance, migrations, or temporary connections.
- Adding another switch would increase rack, power, optics, management, or operational complexity.
The 48Y4C-A is especially useful when the physical port count is the limiting factor. Its four 100G uplinks remain the same as the 24Y4C-A, so the selection should be justified by current and planned downlink demand rather than by uplink bandwidth alone.
When Is the 24Y4C-A the Better Choice?
The C9500-24Y4C-A is appropriate when the project can clearly stay within 24 SFP28 downlink ports and does not require the additional physical capacity of the 48Y4C-A.
Choose the 24Y4C-A When:
- The planned port requirement is comfortably below 24 connections.
- The switch will serve a small aggregation block or a compact campus core.
- The installation has predictable growth and no near-term requirement for more than 24 ports.
- The project prefers a smaller hardware footprint and a simpler initial configuration.
- Unused ports on a 48-port platform would not provide practical value.
A 24-port model can be the more efficient choice when the port plan is well defined. However, the decision should include the expected number of optics, maintenance connections, redundant links, and future additions—not only the number of ports required on day one.
You can review the C9500-24Y4C-A product details when the design is based on a controlled 24-port requirement.
Core, Aggregation, or Collapsed Core?
Neither model is automatically the correct choice for every core design. The better option depends on the number of connected devices, the required port speeds, the redundancy model, and the expected growth period.
| Network Role | 24Y4C-A May Fit When | 48Y4C-A May Fit When |
|---|---|---|
| Campus core | The core has a limited number of high-speed connections and a stable port plan. | The core must terminate many distribution, security, server, or inter-building links. |
| Aggregation | The aggregation block is compact and remains within 24 ports. | Multiple access blocks or high-speed devices need to connect to one platform. |
| Collapsed core | The combined core and distribution design has a controlled number of connections. | The collapsed core must support more downstream links and future expansion without an additional switch. |
For a campus deployment, the practical rule is simple: select the 24Y4C-A when port demand is known and comfortably below 24; select the 48Y4C-A when the design is dense, growing, or difficult to expand later.
If you are comparing both platforms for a specific campus or aggregation design, review the C9500-48Y4C-A product details together with the complete port and optics plan.
Cost, Expansion, and Quote Planning
The 24Y4C-A may reduce the initial hardware requirement when 24 ports are sufficient. However, the lowest initial purchase price is not always the lowest project cost. If the 24-port platform reaches capacity early, the project may later require another switch, additional optics, extra power capacity, new uplinks, and more operational work.
The 48Y4C-A may require a larger initial investment, but its additional fixed ports can reduce the risk of a second hardware purchase caused by insufficient port density. Actual pricing depends on the selected license or subscription, support, power supplies, optics, cables, region, and commercial quotation. These items should be confirmed before budgeting.
Information to Include in a Quote Request
- Required model: C9500-24Y4C-A, C9500-48Y4C-A, or both for comparison.
- Number of 1G, 10G, and 25G downlink connections.
- Number of required 40G or 100G uplinks.
- Optic, DAC, AOC, fiber type, and distance requirements.
- Required Network Advantage and Cisco software subscription term.
- Power supply, redundancy, airflow, support, and deployment-region requirements.
- Target delivery date and planned expansion window.
Cisco’s current Ordering Guide explains that the Network Stack license is embedded in the hardware PID, while a Catalyst Software Subscription or Cisco DNA subscription is a separate ordering consideration. Confirm the exact licensing combination before comparing quotes.
Send your port plan and uplink requirements for a configuration review.
For ordering details, review the Cisco Catalyst 9500 Series Ordering Guide.
Frequently Asked Questions
Final Takeaway
Choose the C9500-24Y4C-A when the deployment needs up to 24 1G/10G/25G connections, has four 40/100G uplinks covered, and has a predictable growth plan. Choose the C9500-48Y4C-A when port density, expansion capacity, or the cost of adding another switch is the main concern.
The two models share the same four 100G uplink count, so the final decision should focus on the number of fixed SFP28 ports required today and during the expected service life of the platform.