This free visual tool lets you design and document enterprise campus and data-center network topologies. Place devices from the palette onto a three-layer canvas (Core / Distribution / Access), draw connections between them, run IPAM to auto-assign an IP addressing plan, and export a complete topology summary with equipment BOM. Use it to plan new deployments, document existing infrastructure, or communicate designs to clients and contractors.
The tool's canvas is organized into three horizontal layer bands that reflect the hierarchical network model:
Core layer (top): High-speed backbone layer. Houses Core Routers and Core L3 Switches that interconnect buildings, data centers, and WAN links. Core devices connect to each other (redundant core ring or dual-homed) and downlink to Distribution switches. Recommended devices: Core Router, Core Switch (L3), Firewall, Load Balancer.
Distribution layer (middle): Policy and aggregation layer. Distribution L3 Switches aggregate connections from multiple Access switches, enforce inter-VLAN routing and ACL policy, and uplink to the Core. Each Distribution switch typically serves 4-8 Access switches. Recommended devices: Distribution Switch (L3).
Access layer (bottom): End-device connection layer. Access L2 Switches connect workstations, phones, printers, and wireless APs to the network. Each access switch uplinks to 2 Distribution switches for redundancy. Recommended devices: Access Switch (L2), Wireless AP.
Click '▶ Run IPAM' to auto-assign a hierarchical IP addressing scheme based on 10.0.0.0/8:
Core point-to-point links: /30 subnets from 10.0.1.0/24 — each link gets a /30 (2 usable IPs). Device loopbacks: /32 addresses from 10.0.0.x.
Distribution management: /24 subnets from 10.10.x.0/24 — each Distribution switch gets a management IP in this range.
Access management: /24 subnets from 10.20.x.0/24 — each Access switch gets a management IP in this range.
Server subnets: /24 subnets from 10.100.x.0/24 — server racks get dedicated subnets here.
End-user VLANs: /24 subnets from 10.200.x.0/24 — workstations and wireless clients land here, segmented by department or VLAN.
All addresses are shown in the device properties panel after IPAM runs and are included in the exported topology summary.
Small Office (50 users): 1 Firewall, 1 Core Switch (collapsed core/distribution), 2 Access Switches, 1 Server, 1 Wireless AP. Total: 6 devices, 5 connections. Suitable for a single-floor office with a simple flat or minimal-segmentation design.
Medium Campus (200 users): 1 Firewall, 2 Core L3 Switches, 4 Distribution L3 Switches, 8 Access L2 Switches, 2 Servers, 2 Wireless APs. Total: 19 devices. Three-tier hierarchy with redundant core and access-layer redundancy.
Enterprise Campus (1000 users): 2 Core Routers, 2 Firewalls, 4 Distribution Switches, 16 Access Switches, 4 Servers, 1 Load Balancer. Total: 29 devices. Dual-core redundancy, firewall cluster, distribution ring.
Data Center Spine-Leaf: 2 Spine Switches (Core layer), 4 Leaf Switches (Access layer), 8 Servers. Total: 14 devices. Every Leaf connects to every Spine — full any-to-any bisectional bandwidth. 2-hop east-west latency between any two servers.
'📋 Export Design' generates a complete topology summary text document including:
Topology summary: All devices listed by layer with their IP addresses and vendor/model information.
Connection list: Every link in the topology shown as Device A ←→ Device B with the connection type.
IP addressing plan: The full IPAM scheme with subnet assignments for each zone (Core links, Distribution management, Access management, Server subnets, Endpoint VLANs).
Equipment BOM: A count of each device type — useful for procurement and cost estimation. The BOM lists device type, quantity, and a typical vendor example for each.
Copy the export text to paste into a Word/Confluence design document, or use it as the starting point for a formal network design specification.
The three-tier model divides a campus network into Core (high-speed backbone), Distribution (policy and aggregation), and Access (end-device connection) layers. This separation provides scalability, fault isolation, and manageability. For smaller deployments, Core and Distribution are often collapsed into a single two-tier model.
Spine-leaf is a two-tier data center architecture where every leaf switch connects to every spine switch (full mesh). Any two servers are exactly two hops apart, providing predictable east-west latency. It scales horizontally and is ideal for EVPN/VXLAN overlay networks in modern virtualized data centers.
IPAM systematically assigns IP addresses across the network using hierarchical subnetting. Core point-to-point links use /30 subnets. Distribution and Access management interfaces get /24 subnets from dedicated ranges. Server and endpoint VLANs get their own /24 blocks. This tool auto-generates a 10.0.0.0/8-based scheme matching these conventions.
L2 switches forward based on MAC addresses within a single VLAN and cannot route between VLANs. L3 switches add IP routing capability via Switched Virtual Interfaces (SVIs), enabling inter-VLAN routing. Distribution and Core switches are typically L3; Access switches are typically L2 (or L3 in a routed-access design).
Plan for 36-40 active users/devices per 48-port access switch (accounting for APs and 25% spare capacity). For 200 users, 8 access switches. For 1000 users, 28-32 access switches. Each access switch uplinks to 2 distribution switches for redundancy using 1G or 10G fiber.