What is a network topology diagram?

A network topology diagram is a visual representation of a network's structure showing how devices are connected. It comes in two forms: Physical topology shows the actual physical layout — where cables run, where devices are located in the building. Logical topology shows how data flows through the network — the logical connections, IP addressing, VLANs, and routing paths regardless of physical layout. Network diagrams use standard symbols: cloud (internet/external network), cylinder (router), rectangle with multiple ports (switch), monitor (workstation), server icon (server). Tools: Cisco Packet Tracer, GNS3 (network simulators), Microsoft Visio, draw.io, Lucidchart. Network diagrams are essential documentation for network administrators — they help with troubleshooting, planning upgrades, and training. Keeping diagrams up-to-date is a best practice that many organizations neglect.