Documenting networks is important; we all know that. And since an image is worth a thousand words, the best network documentation one can have is a network diagram. So much information can be packed in a network diagram that it makes it one of the best troubleshooting tools. They can often help administrators precisely pinpoint the location of faults. But contrary to a house plan, which is usually done before building it, network diagrams are often done after the network has been put in place; sometimes much later.
To create a great topology diagram of an existing network, you should use the proper tool. The only problme is, there are plenty of them out there. So many that selecting the right one for you could be overwhelming. Today, we’re having a look at some of the best network topology mapping tools and software.
We’ll begin with a discussion on network documentation in general. We’ll have a look at what it is and why it’s important. We’ll also discuss the different types of documentation that there are. And just like there are different types of documentation, there are different types of tools. For the purpose of this article, there are essentially two types. We’ll have a look at these. And last but certainly not least, we’ll rev the best tools we could find under each category, starting off with technology mapping tools as they are really the most interesting as they tend to do the bulk of the hard work—gathering information– for you. We’ll complete with reviews of the best network diagram tools, a type of tool that will help you create nicer looking diagrams at the cost of you doing most of the work.
About Documenting Networks
Everyone has his own reason for needing network topology diagrams. However, some are more common than others. The most important and most common stems from the fact that any system is just as good as its documentation. And when the system is a computer network, a topology diagram is possibly the best type of documentation. Topology Diagrams can include a ton of information. They will typically tell you what each piece of equipment is, how everything is interconnected and they will often include extra details such as IP addresses or other configuration parameters.
A network topology map diagram is also an invaluable troubleshooting tool. And when something is wrong with the network, you’ll be glad you have one. Let’s, for example, say there is a report of poor performance between a workstation and a server. A network diagram would quickly let you figure out what devices are on the path, giving you a starting point for troubleshooting.
Some will say that Network topology diagrams are not needed. After all, nothing beats the mental image an administrator has of its network. While this might hold some truth, it’s also a risky prospect. As time goes by, we can forget the smaller details. The Chinese say that the lightest ink is better than the best memory. While one may still have a pretty good mental picture of how that five-year-old network, they might not remember all the minute details. And to make matters worse, other administrators may have done some unknown changes.
Documentation is really the very best way to keep track of everything and, when it comes to networks, a topology map is certainly the best type of documentation one can have. But networks, like most other things in life, do evolve and changes are regularly—if not constantly—done. Devices are added, circuits are upgraded, configurations are modified. All these changes should be documented. Like the network it depicts, the network topology map should be a constant work in progress and great care must be taken to keep it up to date. Nothing can be more frustrating than trying to debug network issues with outdated diagrams.
Different Types Of Tools
Network topology mapping and diagram tools vary greatly. Part of that has to do with the different needs of network administrators. But, more importantly, there is not really any consensus among the community on what they are exactly. Some vendors view them simply as drafting aids which can replace the drafting tables, squares, rulers, and mechanical pencils of days bygone. To others, they are advanced software that will automatically discover devices, plot their interconnections, download their configuration, and more, leaving little work left to the user. Others yet see them as complete management systems with very advanced features. For our purposes, we’ve identified two basic type of tools: topology mapping tools and drawing tools.
Topology Mapping Tools
Topology mapping tools typically do much more than just help you draw network topology maps. Some can use SNMP and/or other protocols such as the Cisco Discovery Protocol (CDP) to poll your devices and discover their interconnections. They will use that information to automatically build a graphical representation of your network, a network topology map.
While these tools can save you a tremendous amount of time, they can be far from perfect and their drawings will often need some degree of manual editing. You could, for instance, want to overlay the topology map on a building floor plan. For that purpose, many of the topology mapping tools include some editing facilities. Others will let you export the generated diagrams and edit them using a more conventional drawing tool of your choice.
The more advanced tools in this category resemble management systems more than documentation systems. You can use them to monitor devices status and performance. In some instances, they can even allow you to manage devices right from within the tool.
Network Diagram Tools
The second type of tools is the network drawing tool. They differ from the tools in the previous category in that they will only help you with the actual drawing of your network maps. You’ll have to do the research and figure the interconnections. They’re essentially the computerized version of a drafting table and set of drawing tools. Don’t let that diminutive description fool you, though. These are certainly not useless tools. And anyone who has done manual drafting in the past and now does it on a computer will tell you how more practical it is.
Some of the more advanced tools offer quite interesting features beyond simple drafting. Features like letting you script actions to perform when clicking certain objects on your drawing. A clever administrator can turn such a tool into a management system. For instance, a network topology map could be set up so that clicking a device opens a terminal connection to it or pulls its most recent configuration file from a database.
The Best Topology Mapping Tools
We’ve scoured the market for some of the best network topology mapping tools we could find. While some are “just” topology mapping tools others have extended features that turn them into monitoring tools. But to be included on this list, that had to include at least one major feature, automating the process of mapping network topology.
SolarWinds has acquired a solid reputation in the field of network administration tools. In the past 20 years, the company has made quite a few excellent network administration tools. Its flagship product, the Network Performance Monitor is one of the best SNMP monitoring tools. But the company is also well-known for its free tools. They are smaller tools which typically address one specific need of network administrators. Examples of these free tools include a subnet calculator or a syslog server.
The SolarWinds Network Topology Mapper (also called NTM) is an evolution of LanSurveyor, a relatively old tool that was acquired by SolarWinds a while ago. This tool can automatically discover your LAN, your WAN or both and generate comprehensive, easy-to-view, and easy-to-comprehend network topology diagrams. Those diagrams typically integrate Layer 2 and Layer 3 information. The NTM uses an innovative concept called topology databases. The network scanning process does populate these databases which are, in turn, used to create the topology diagrams. This is great as it does allow many different maps to be built from a single scan of the network, thereby saving time and resources.
Something else we liked about the SolarWinds Network Topology Mapper is that it can automatically keep diagrams up to date. It regularly re-scans the network looking for changes in topology and for new devices, adding the new information to existing diagrams. The product can also help with network security. It can, for instance, detect rogue devices that have been connected to the network.
Even better, this tool can assist with PCI/DSS and other regulatory compliance requirements. And it can be used as a networking equipment inventory management system. And if you want to share the tool’s topology diagrams with the rest of the world, you’ll be able to export them in Microsoft Visio format, a standard in business diagrams.
The SolarWinds Network Technology Mapper sells for $1 495, not much considering all it can do for you. And if you’d rather try the product before purchasing it, a free 14-day evaluation is available.
Intermapper from Help Systems is an interesting tool that’s available for Windows, Mac, and Linux. This tool, like the previous one, will auto-discover all of your physical and virtual equipment and place it on a map showing all their interconnections. After that, you simply need to edit the maps to better depict your real-life network. You could, for instance, change the layout, customize the icons or change the background images.
Intermapper is not just a topology mapping tool, it is also a pretty good monitoring solution. It possibly won’t rival with some of the better network monitoring tools but it has some unique features. For instance, it’s got live color-coding and animation which highlights the status of your devices. For example, the color of device icons will go from green (all good) to yellow (warning) to orange (alert) to red (down). Likewise, animated traffic indicators will alert you of any segment where traffic exceeds a predefined threshold.
Intermapper is available in a free version that is limited to 10 devices. For larger installations, you can choose between annual subscriptions or permanent licenses. Prices do vary according to the number of discovered, mapped, and monitored devices. A free 30-day trial is also available.
Like the previous product on our list, NetProbe offers quite a bit more than network topology mapping. In fact, its publisher calls it “a real-time device monitoring tool”. And this is really what it is. This tool will monitor any network-attached device in real time. It has a rich graphical user interface which is available as a stand-alone application or via a web interface.
NetProbe’s graphical layout includes much more than just the devices. Alarms and trackers are also integrated. All drawing elements have been kept as simple as possible making for a simple, quick, and neat representation of the monitored environments. Auto-detection of devices is another excellent feature of this tool. And although it will scan your network to detect devices and add them to its diagrams, this is not all it will do. It will also automatically add alarms and graphs that are pertinent to each device.
NetProbe is available in four license tiers which range from the free standard license which only allows for eight devices to the Enterprise license which is good for up to 400 devices.
4. Network Notepad
We weren’t sure if we should include the Network Notepad in this category or the next one. It is, in essence, a drawing tool. However, useful add-ons are available that will make the product perform somewhat like other tools in this list. First things first, As a drawing tool. This one has all the features one would normally expect including multi-page diagrams, custom shapes, grouping and locking—allowing you to combine existing shapes to create new ones, auto-alignment, and of course, templates.
But as we said, and this is why it ended up in this category, Network Notepad get the bulk of its power when on starts using its add-ons. One of the most interesting is undoubtedly the CDP Neighbor Tool, a sort of auto-discovery utility. This add-on uses the Cisco Discovery Protocol (CDP) to automatically identify and document devices interconnections. All you need to do is right-click any device in your diagram, select “Discover Neighbors“, and the add-on will use the SNMP protocol to fetch data from the device’s CDP table. It will get a list of all devices connected to the selected one and their interconnection interfaces. Subsequently clicking the “Paste” button will add any missing connected objects to your diagram.
The Network Notepad is available as a feature-reduced Freeware version or as a Professional version which you can purchase for only 18 British Pounds once the 30-day trial period expires. At that price, it is a pretty good deal, considering its features.
The Best Tools To Create/Edit Network Diagrams
Next are simpler drawing tools that are meant to be a replacement for the drafting table tools of the past. We’re saying simple but some of them are actually quite complex and feature-rich. Those tools will help you draw topology maps of your network but you will have to provide the background information and draw the interconnections and relationships between devices yourself. Our list contains a mix of wide-range CAD tools and highly specialized network topology drafting tools.
5. Microsoft Office Visio
It is hard to talk about business drawing tools without talking about Microsoft Office Visio—or, more simply, Visio—as it has been the de facto standard for a while. The software was introduced way back in 1992 and was acquired by Microsoft in 2000 when it was integrated as an optional component of the Microsoft Office Suite.
The main differentiating feature of Visio is its use of objects stencils as the primary way to add objects to a drawing. There are sets of stencils for all sorts of use built right into the product, including many for network equipment or network symbols. Furthermore, many major manufacturers—such as Cisco Systems, for example—offer downloadable Visio stencils which contain custom shapes that you can use in your network diagrams.
The pricing structure of Visio is complex and price varies whether you purchase it as a component of Microsoft Office or a standalone product. It is available as an online-only option starting at $5/month or as a locally-installed product starting at $15/month. These prices are for a one-year commitment.
Dia is a free, open-source tool that closely resembles Visio. Some dare to call it a Visio clone. We’re including it on our list for the more business-conscious of you. Dia will give you the Visio look-and-feel—and a lot of its functionality—without spending a dime. This tool is obviously based on Visio albeit with a slightly reduced feature set. But most of the Visio features which are missing from this product are not really needed for making network topology diagrams.
Dia uses stencils and networking equipment stencils are available, just as are many more templates. Diagrams created with it can be saved in a custom XML format and can also be exported to several other vector or bitmap formats such as EPS, SVG, XFIG, and PNG. What’s mostly missing from the tool is a way to import from and export to Visio format. Dia is released under the GPL license and its available for free. It is available for Linux, Unix, OS X, and Windows.
Last on our list is LanFlow, a dedicated network topology diagramming solution. You can use this tool to create many different types of LAN, Internet, telecommunications and computer network diagrams. Imagination and inspiration are the only limits to what information can be included in a LanFLow diagram. You can use this tool to draw a network topology map, show cabling and wiring, and document flows and processes.
LanFlow boasts both 2D and 3D networking symbols, outline symbols, and some basic block diagram symbols. Custom clip-art representing your specific networking equipment can easily be added to this tool. If all your drawing needs have to do with networks, this is one of the easiest and fastest solutions available.
Prices for LanFlow start at $99 for a single user and varies according to the number of user licenses you purchase. If you’d like to try the software before buying it, a free 30-day trial version can be downloaded.