Home » Network Design Patterns: Three-Tier, Spine-Leaf, Collapsed Core, Campus และ Data Center
Network Design Patterns: Three-Tier, Spine-Leaf, Collapsed Core, Campus และ Data Center
Network Design Patterns: Three-Tier, Spine-Leaf, Collapsed Core, Campus และ Data Center
Network Design Patterns เป็น architectural blueprints สำหรับสร้าง network ที่ scalable และ resilient Three-Tier (Core-Distribution-Access) เป็น classic campus design, Spine-Leaf เป็น modern data center fabric, Collapsed Core รวม core กับ distribution สำหรับ small sites, Campus Design ออกแบบสำหรับ office buildings และ Data Center Design รองรับ east-west traffic patterns
การเลือก network design pattern ที่ถูกต้อง กำหนด scalability, performance และ cost ของ network ทั้งหมด: Three-Tier ดีสำหรับ campus ที่มี north-south traffic แต่ไม่เหมาะกับ data center ที่มี east-west traffic สูง Spine-Leaf ให้ consistent latency และ scalability สำหรับ data center แต่ overkill สำหรับ small office
Three-Tier Architecture
| Layer |
Role |
Devices |
| Core |
High-speed backbone — forward traffic between distribution blocks |
High-end routers/switches (Cisco 9500, Nexus 9000) |
| Distribution |
Policy enforcement, inter-VLAN routing, summarization, redundancy |
L3 switches (Cisco 9300, 9400) |
| Access |
User/device connectivity — port security, PoE, VLANs |
Access switches (Cisco 9200, 9300-L) |
Three-Tier Design Rules
| Rule |
Detail |
| Core = Transport |
No policy at core — fast forwarding only (minimal features enabled) |
| Distribution = Policy |
Route summarization, ACLs, QoS marking, inter-VLAN routing |
| Access = Edge |
802.1X, PoE, VLANs, port security, DHCP snooping, DAI |
| L3 at Distribution |
Route at distribution layer (not core) — contains broadcast domains |
| Dual-Homed |
Every distribution switch uplinks to 2 core switches (redundancy) |
| No Triangles |
Avoid L2 loops — use L3 links between distribution-core (no STP dependency) |
Spine-Leaf Architecture
| Feature |
รายละเอียด |
| คืออะไร |
2-tier fabric: every leaf connects to every spine (full mesh at spine layer) |
| Leaf |
Top-of-Rack (ToR) switches — connect servers, storage, firewalls |
| Spine |
Fabric switches — only connect to leaves (no server connections) |
| ECMP |
Equal-Cost Multi-Path — traffic load-balanced across all spines |
| Consistent Latency |
Any server ↔ any server = exactly 2 hops (leaf → spine → leaf) |
| Scale Out |
Add more spines = more bandwidth | Add more leaves = more ports |
| L3 Everywhere |
L3 routed fabric (BGP or OSPF between leaf-spine) — no STP |
Three-Tier vs Spine-Leaf
| Feature |
Three-Tier |
Spine-Leaf |
| Traffic Pattern |
North-South (client → server → internet) |
East-West (server ↔ server within DC) |
| Latency |
Variable (depends on path through tree) |
Consistent (always 2 hops) |
| STP |
Required (L2 at access/distribution) |
Not needed (L3 everywhere, ECMP) |
| Scalability |
Limited by core capacity |
Scale out by adding spines/leaves |
| Oversubscription |
Common at distribution-core (cost saving) |
Non-blocking possible (1:1 ratio) |
| Best For |
Campus networks, traditional enterprise |
Data centers, cloud, hyperscale |
Collapsed Core
| Feature |
รายละเอียด |
| คืออะไร |
Merge core + distribution ไว้ในชั้นเดียว → 2-tier design (collapsed core + access) |
| Use Case |
Small-medium sites (< 200 users) ที่ separate core ไม่คุ้ม |
| Design |
2 collapsed-core switches (L3, redundant) + access switches |
| Advantage |
ลดค่าใช้จ่าย (น้อย switches), ง่ายขึ้น (น้อย layers) |
| Limitation |
ไม่ scale เท่า 3-tier — ถ้าโตเกิน → ต้อง add dedicated core |
Campus Design Best Practices
| Practice |
Detail |
| Hierarchical |
Use 3-tier (large) หรือ collapsed core (small) — never flat L2 |
| Modular |
Design ใน building blocks — each building/floor = distribution block |
| Redundant |
Dual uplinks, dual core, dual power, dual supervisors |
| L3 Routing |
Route at distribution (or access) — minimize L2 domains |
| Wireless Integration |
Dedicated overlay or converged access (WiFi + wired on same switch) |
| Segmentation |
VLANs per function (data, voice, IoT, guest) + ACLs/firewall between |
| Automation |
Cisco DNA Center, Aruba Central, Juniper Mist — automate provisioning |
Data Center Design
| Approach |
Technology |
Use Case |
| Spine-Leaf + VXLAN EVPN |
BGP EVPN control plane + VXLAN data plane |
Modern DC (L2 extension over L3 fabric) |
| Cisco ACI |
Application Centric Infrastructure (APIC controller) |
Cisco shops — policy-driven DC networking |
| VMware NSX |
Network virtualization (micro-segmentation) |
VMware environments — overlay networking |
| SONiC (Open Source) |
Software for Open Networking in the Cloud |
Hyperscalers, large DCs (Azure, Alibaba use SONiC) |
ทิ้งท้าย: Choose the Right Pattern for the Right Use Case
Network Design Patterns Three-Tier: core (transport) + distribution (policy) + access (edge) — campus standard, north-south traffic Spine-Leaf: leaf (ToR) + spine (fabric), ECMP, consistent 2-hop latency, L3 everywhere — DC standard Collapsed Core: merged core+distribution for small sites (< 200 users) — cost-effective 2-tier Campus: hierarchical, modular, redundant, L3 at distribution, wireless integration, automation Data Center: spine-leaf + VXLAN EVPN (modern), ACI (Cisco), NSX (VMware), SONiC (open source) Key: campus = three-tier/collapsed core | data center = spine-leaf | match traffic pattern to architecture
อ่านเพิ่มเติมเกี่ยวกับ VXLAN EVPN Fabric BGP EVPN และ Kubernetes Networking CNI Service Mesh ที่ siamlancard.com หรือจาก icafeforex.com และ siam2r.com
