Understand the certification
300-420 ENSLD（Designing Cisco Enterprise Networks）是 CCNP Enterprise 6 门可选专项之一，也是唯一一门偏"设计"而非"实施"的考试。60 题 / 90 分钟，通过分约 750-800/1000。
考试覆盖企业网络的高层设计方法论：Campus LAN 架构（三层 vs 两层、SDA Fabric）、WAN 架构（MPLS/DMVPN/SD-WAN 选型）、数据中心互联（OTV/VXLAN）、高可用设计（FHRP 选型、路由汇聚、冗余拓扑）。和 350-401 ENCOR 的区别在于：ENCOR 考"怎么配"，ENSLD 考"为什么这么设计"。
Cisco SAFE（Security Architecture for Enterprise）和 CVD（Cisco Validated Design）文档是考试的理论基础。约 20% 的题涉及 QoS 设计（信任边界、流量标记策略）和 IP 地址规划（VLSM、汇总路由计算）。
Exam at a glance
- Exam code
- 300-420
- Provider
- Cisco
- Format
- Single choice / Multiple select
- Language
- English
- Validity
- 3 years
- Exam fee
- $330
Skills in focus
Learning outcomes
- Prepare for the Cisco 300-420 ENSLD exam with a structured study path
- Make better enterprise network design decisions across campus, WAN, and service layers
- Build the design thinking required for CCNP Enterprise and architecture work
- Strengthen your profile for network design and solution architecture roles
Who this is for
- Network engineers moving into design and architecture work
- CCNP Enterprise candidates taking the design concentration path
- IT professionals who need to make enterprise networking design decisions
- Engineers who want stronger campus, WAN, and service design skills
Before you start
- CCNA or equivalent networking knowledge is recommended
- You should already be comfortable with routing, switching, and basic enterprise topologies
- Hands-on exposure to Cisco enterprise networks or labs will help
- Familiarity with wireless and WAN basics is useful but not mandatory
Your learning path
6 chapters
Plan your preparation
- Learning hours
- 40h
- With relevant experience
- 4-6 weeks
- Starting from scratch
- 8-10 weeks
- Daily study
- 1-2h
Included in your preparation
- 288 practice questions focused on design decisions, not just configuration recall
- Coverage of addressing, routing, campus, WAN, DCI, QoS, and security design
- Mock-exam style practice aligned to the official 120-minute exam format
- Clear explanations that show why one design choice fits better than another
- Useful for engineers moving toward architect or lead network roles
1. 第一阶段：企业网络设计方法论（1-2 周）
精读 Cisco SAFE 白皮书和 CVD（Cisco Validated Design）指南。理解三层架构（Access/Distribution/Core）向两层（Collapsed Core）演进的决策逻辑，以及 SDA Fabric 的 Underlay-Overlay 设计原则。
2. 第二阶段：WAN 和数据中心设计（2-3 周）
对比 MPLS、DMVPN、SD-WAN 三种 WAN 方案的适用场景和成本模型。学习 VXLAN EVPN 的 data center fabric 设计。IP 地址规划和路由汇总计算必须熟练 — 考试一定会出 VLSM 计算题。
3. 第三阶段：高可用和 QoS 设计 + 模考（1-2 周）
FHRP（HSRP/VRRP/GLBP）选型场景、BFD 快速故障检测、QoS 信任边界设计。做 2-3 套模考，注意设计题没有"唯一正确答案"，要选"最符合 Cisco 推荐实践"的选项。
Career value
ENSLD 是少数考"设计思维"的网络认证，对 Network Architect 和 Pre-sales SA 有直接价值。Cisco 合作伙伴的 ATP（Advanced Technology Provider）资质通常要求团队中有 ENSLD 持证人。
适合考的人：3+ 年网络经验、正在从运维转向设计角色的工程师，或者需要做客户方案设计的合作伙伴 SE。
不适合考的人：纯做运维和故障排除的 NOC 工程师 — ENARSI（300-410）更实用。
- 澳洲
- AUD 130,000 – 170,000
- 美国
- USD 110,000 – 160,000
- 新加坡
- SGD 90,000 – 140,000
Preparation tips
Common mistakes
- **把 ENSLD 当 ENCOR 来准备** — ENSLD 不考配置命令，考的是"为什么选 A 而不是 B"。需要理解设计决策的 trade-off。
- **忽略 SDA Fabric 设计** — Cisco DNA Center + SDA 是 Cisco 主推的 Campus 架构，考试比重约 20-25%。
- **VLSM 计算不熟练** — 给你一个 /22 网段要求划分给 4 个部门不同大小的子网，必须又快又对。
Before you register
How difficult is the 300-420 ENSLD exam?
The exam is 120 minutes long and we recommend 3-6 months of systematic preparation. Using our structured practice questions and mock exams can significantly improve your chances of passing.
How much does the exam cost?
The 300-420 ENSLD exam fee is $330 USD. The certification is valid for 3 years.
Learner experiences
Loading reviews…
和 ENCOR 完全不同的考法 — ENCOR 是"show 命令看什么"，ENSLD 是"客户有这些需求该选哪种架构"。SDA Fabric 设计至少出了 6-7 道题，必须搞清楚 Control Plane Node / Border Node / Edge Node 各自干什么。
J. Park
Network Architect @ MSP · 810/1000 · 5 weeks
IP 地址规划和路由汇总计算不难但容易粗心，我在这上面丢了至少 3 分。QoS 设计题比想象中多，信任边界（trust boundary）在 Access Switch 还是 IP Phone 上设置要搞清楚。
网络运维 5 年转 SA
Cisco 合作伙伴 · 8 weeks
Start with the first chapter.
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