Free Network Diagraming Tools
You should always have an up-to-date map or diagram of your network. It should depict the connection of gateways, routers, switches, APs, servers, and other network components along with their basic details like vendor names, model numbers, IP and MAC addresses, and serial numbers.
You can store this diagram with your network’s other documentation so you and others can reference it when needed. It can be useful, for instance, when you bring on a new IT team member or if an outside IT provider comes in to help. Plus file it with your disaster recovery information as well. Creating a good network diagram, among other documentation, should be able to help any IT person setup and configure the same exact network from scratch.
Here I introduce a couple of different free tools you can use for creating your network diagram. One provides network scanning or probing functionality to help detect network components and devices, whereas the others are only a vector graphics editor for designing diagrams, flowcharts, schemas, and other technical graphics.
Spiceworks offers a Network Map tool as part of their free IT and help desktop management solution. Although it scans for and monitors network devices to automatically generate a map, it’s a relatively simple tool and doesn’t provide advanced graphic editing features.
You can have it initially generate a map of just the backbone or all devices, and change between radial, hierarchy, tree layouts. After the initial map is generated you can make manual edits. The Network Map tool works alongside the Inventory functionality, so you can add/edit details of devices in the Inventory so they appear in the Network Map tool.
Spiceworks also lets you see bandwidth usage between nodes and other monitoring services like keeping tabs on ink and toner levels.
Network Notepad is offered in a Freeware and Professional edition. It’s primarily a diagramming and flow chart tool only, but the CDP Neighbor Tool add-on offers network scanning to help detect connected devices in your network via CDP Neighbor tables.
I reviewed the Freeware edition, which offers pretty crude looking graphics for networking the main components and for flow charts as well. It allows you to input and show IP addresses for each component. It saves in the NDG file format and can also export the diagram as a Bitmap image.
The Professional edition has improved graphics, supports tabbed multi-page diagrams, customizable shapes, and enhanced editing, such as grouping, locking, and rotation of objects and text.
CADE is a relatively advanced 2D vector editor offered in a Freeware and Professional edition, providing functionality close to that of Visio. You can create network or other diagrams, flowcharts, schemas, maps and more.
I reviewed the Freeware edition, which lacks some of the features available in the Pro edition. It includes a few different groups of network-related graphics, one of which is photo realistic. The network graphics are preconfigured with attributes (IP address, serial number, and manufacturer) you can define, plus you can add your own custom attributes. You can save and export drawings to a variety of formats, including DTC, AutoCAD, WMF, JPG, and PDF.
In addition to the Professional edition, they also offer CADE Server that offers collaborative functionality and CADE Control, an ActiveX control that can be integrated into any visual development environment including VS.NET, Visual C++ 6.0, Visual Basic 6.0, Delphi and Microsoft Java.
Dia is an open source multi-platform software available for Windows, Mac OS X, and Linux via GPLv2 license. It can be used for creating more than 30 different diagram types like flowcharts, network diagrams, and database models across a couple of different industries.
Dia provides more than 1,000 predefined objects and symbols, though none are photo realistic. Although it doesn’t have any preconfigured attributes like for the IP addresses, you can add custom text labels to the objects and symbols. Dia can read and write a number of different raster/vector image and AutoCAD formats, including DXF, WMF, SVG, VDX, BMP, GIF, PNG, JPG, and PDF. It also supports scripting and execution via Python.
Diagram Designer is a simple Windows open source vector graphics editor for creating flowcharts, UML class diagrams, illustrations and slide shows.
Diagram Designer includes a customizable template object palette. Although it comes with limited preloaded objects/graphics, you can download many more submitted users, including those for networking. It supports import/export via WMF, EMF, BMP, JPEG, PNG, MNG, ICO, GIF and PCX images.
It also features a simple graph plotter to plot mathematical expressions and an advanced "pocket" calculator with equation solver. Plus the MeeSoft Image Analyzer integration provides bitmap image editing and extended file format support. It also includes a few features not found in other simple editors, including a spellchecker and a slide show viewer.