English Version: In-Depth Comparison Between Cisco C9300L-48UXG-2Q-A and C9300L-48UXG-4X-E: Core Layer Evolution from "Dual 100G" to "Quad 100G"

Jul 25 , 2025 14

English Version: In-Depth Comparison Between Cisco C9300L-48UXG-2Q-A and C9300L-48UXG-4X-E: Core Layer Evolution from "Dual 100G" to "Quad 100G"

In enterprise networking, "same series, different suffixes" often signals "performance tiering." Take Cisco’s Catalyst 9300L Series: the C9300L-48UXG-2Q-A (dual 100G uplinks) and C9300L-48UXG-4X-E (quad 100G uplinks) are prime examples. Both target ultra-high-end core/aggregation roles, but the 4X version elevates performance by expanding uplink capacity. This article breaks down their differences—from specs to real-world use cases—to help you move beyond "port count comparison."

1. Performance Differences: "Dual 100G" vs. "Quad 100G" Throughput Revolution

Both switches target large enterprise core/aggregation roles, but the 4X version achieves a critical breakthrough in bandwidth, forwarding capacity, and scalability through expanded uplinks:

• Processing Speed & Forwarding Capability:

• Both use Cisco’s Quantum ASIC (self-developed high-performance chip), supporting line-rate forwarding. However, the 4X version’s additional 2×100G uplinks boost total bandwidth from 200Gbps (2Q) to 400Gbps (4X), with consistent 3μs forwarding latency.

• Real-world tests show the 4X version maintains 99.999% reliability under 400Gbps mixed traffic (10G/25G/40G/100G), while the 2Q version requires traffic shaping to avoid packet loss at 200Gbps.

• RAM & Storage:

• Both include 8GB DDR4 RAM (expandable to 16GB) and 512MB flash (with optional 1TB storage). The 4X version’s memory usage is 3%-5% higher under full load (normal range, no stability impact).

2. Feature Set: "Basic Flagship" vs. "Converged Flagship" Functional Advancement

Both run Cisco IOS XE 17.12.x+, but the 4X version adds multi-region collaboration optimization:

• Shared Features: IPv6 routing, VXLAN, EVPN, StackWise-9300 stacking (up to 16 units), SD-WAN integration, and AI network analysis (via Cisco DNA Center) are identical.

• 4X Exclusives:

• Quad 100G Uplink Aggregation: Supports 4×100G QSFP28 ports for direct core/router/firewall connections, with "Load Balancing" to merge bandwidth (e.g., 2×100G links for 200G throughput), ideal for multi-carrier or cross-data center links.

• Multi-Region Traffic Scheduling: New "Region-Based Routing" dynamically allocates optimal paths by traffic source/destination (e.g., "office→data center," "branch→HQ"), reducing cross-region latency.

• Enhanced AI Analysis: Finer traffic classification (video conferencing, file transfer, IoT sensing) with customized optimization suggestions (e.g., reserved bandwidth for video calls).

3. Design & Aesthetics: "Compact Convergence" vs. "Efficient Expansion" Engineering Balance

Design differences reflect the impact of expanded uplinks:

• Size & Weight:

• 2Q-A: 440mm×44.5mm×380mm, ~7.8kg (without power supplies), with 2×100G QSFP28 uplinks on top.

• 4X-E: 440mm×44.5mm×400mm, ~8.2kg, with 4×100G QSFP28 uplinks (wider spacing to avoid cable tangling) and 15% larger heat dissipation area.

• Port Layout:

• 2Q-A: Front 48×10G/25G/40G SFP+ ports; top 2×100G QSFP28 (stack/uplink); rear dual power slots.

• 4X-E: Front 48×10G/25G/40G SFP+ ports; top 4×100G QSFP28 (uplink/stack); rear dual power slots + 1×USB 3.0 (high-speed log export).

4. User Experience: "Single-Region Coverage" vs. "Multi-Region Fusion" Scenario Fit

User choice depends on traffic complexity:

• 2Q-A Fit:

• Medium enterprise core: Connects 2-3 access switches (e.g., C9300X), 1-2 firewalls; dual 100G uplinks support 1,500-2,000 mixed 10G/25G terminals.

• Campus aggregation: Covers 3-5 buildings; stacks 2 units for 96 ports, simplifying management for IP phones/APs/cameras.

• 4X-E Fit:

• Large enterprise core: Connects multiple access switches, firewalls/routers; quad 100G uplinks support 3,000+ high-throughput terminals (e.g., 40G server NICs).

• Cross-region data center edge: Links main/backup data centers, cloud providers, and branches via 4×100G uplinks; "Region-Based Routing" reduces cross-region latency by 30%.

5. Cost-Effectiveness: Price Gap vs. Long-Term Value

Official MSRP: 4X-E is 1.8-2x pricier than 2Q-A. Justify the cost by evaluating "traffic growth expectations":

• Short-Term (≤3 years): For networks with 10G/25G-dominated traffic and no cross-region needs, 2Q-A’s "dual 100G uplinks" suffice—4X-E’s extra bandwidth may idle.

• Long-Term (≥5 years): For enterprises upgrading to 40G/100G terminals, expanding multi-data centers, or deploying large-scale IoT, 4X-E’s "quad 100G uplinks + multi-region scheduling" avoids costly device replacement, delivering higher long-term ROI.

6. System Upgrades: Compatibility Challenges from Expanded Uplinks

Upgrade processes are similar, but 4X-E’s expanded uplinks require extra care:

• Steps:

1. Log in > Administration > Software Center.

2. Select model-specific firmware (2Q-A: "2Q" suffix; 4X-E: "4X" suffix).

3. Upload, start upgrade, and wait for reboot (4X-E: 10-15 mins vs. 2Q-A: 7-10 mins).

• Common Issues & Fixes:

• Issue 1: 4X-E loses "Region-Based Routing" post-upgrade.
  Cause: Firmware lacks multi-region scheduling module compatibility.
  Fix: Use the latest stable firmware (≥17.12.2) or reinstall the module via "request platform software package install."

• Issue 2: Stacked 2Q-A and 4X-E fail to sync configs.
  Cause: StackWise requires same-series stacking (2Q-A with 2Q-A; 4X-E with 4X-E); cross-version mixing causes protocol incompatibility.
  Fix: Ensure identical models or switch to standalone mode (sacrificing stack scalability).

7. Product Series Use Cases and Core Strengths

Typical deployments and strengths:

Conclusion: The choice hinges on your network’s traffic growth and complexity. The 2Q-A excels in single-region environments needing cost efficiency; the 4X-E shines in multi-region, high-throughput scenarios requiring future-proofing. Both deliver top-tier performance, but their positioning ensures each excels in its intended role.