At some point, every administrator will need to diagram a network. For some, it’s their primary duty — and they tend to rely on powerful, expensive tools like Microsoft Visio. But for those who need to use a diagramming tool only occasionally, a cheaper solution is best.
Below are the best free best tools to use in Small business centers and for occasional users.
These tools could be used to create diagrams, network diagrams, flowcharts, schemas, maps and so much more. You can use predefined blocks, primitive shapes, raster, and vector images.
Draw is part of the LibreOffice suite, an open-source alternative to Microsoft Office. Side-by-side, Draw is similar to Visio in terms of functionality—offering the ability to create basic or complex diagrams, anything from flowcharts and organizational charts to network diagrams and 3D sketches.
LibreOffice Draw runs on Windows, Linux, and Mac OS X.
Tip: LibreOffice Portable lets you run any of the tools from a USB, local hard drive, or the cloud.
To get started, you will need to download and apply a network topology icons pack, available in the form of an extension. A couple of popular ones are VRT Network Equipment and Cisco Network Topology Icons
To apply for the VRT Network Equipment icons, go to Tools > Extension Manager > Add > choose the extension file you downloaded and it will be added automatically to your extension list.
Alternatively, if you have your own icons or images you wish to use in your diagram, you can add them to your gallery. Open the Gallery by clicking on the icon on the right-hand side, or going to Insert > Media > Clipart Gallery. Here, you can create a New Theme folder and add your images or icons to that folder.
For portable version : https://www.libreoffice.org/download/portable-versions/
CADE is a compact but powerful 2D vector editor for Windows. It includes basic Visio functionality and could be used to create diagrams, network diagrams, flowcharts, schemas, maps and so much more.
Free sample diagrams are available to help you get started.
CADE is available for free download.
Draw.io is a free, cloud-based, online diagramming software solution that allows you to create basic network diagrams from a user-friendly interface. You can save directly to Google Drive, Dropbox, OneDrive, or your own device and export the finished product in PNG, SVG, HTML, PDF, or XML format.
Click More Shapes, on the bottom left-hand side, to choose more shapes from pre-defined categories. The Scratchpad allows you to add your own images by dragging and dropping, importing from a file, or specifying an image URL.
Dia is an open source, GTK+ diagramming tool that has a shallow learning curve and can help you create basic network diagrams. Like CADE, Dia was inspired by Visio — but with a much more casual approach and feel. Dia loads and saves XML-formatted documents that are gziped by default to save space. Dia is also available for Linux, Mac, and Windows.
yEd is freely available and runs on all major platforms: windows, Unix/Linux, and Mac OS X. It has a great user interface and features diagram creation, auto-layout, data import (GraphML, Excel XLS, GEDCOM, GML, XML), and data export (PDF, SWF, JPG, GIF, BMP, and HTML image maps). The auto-layout feature is particularly cool. It uses a wide range of sophisticated layout algorithms to automatically arrange your diagrams, saving you time and effort.
Diagram Designer is another freeware tool that suffers (like Dia) from looking a bit on the outdated side. But Diagram Designer’s ease of use should certainly make up for the old-school feel of the application. DD features include customizable template objects, a spell checker, import/export (WMF, EMF, BMP, JPEG, PNG, MNG, ICO, GIF, and PCX), a slideshow viewer, a graph plotter, a calculator, MeeSoft Image Analyzer integration, and compressed file format.