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Beware the quick draw

Design software can be one of the most valuable tools in the network architect's arsenal - provided it's accurate.

By JEFFREY FRITZ
Network World, 05/03/99

Network diagramming products are prone to evolution by natural selection. Simple drawing programs are losing shelf space to more sophisticated packages that include IP autodiscovery in their feature sets. This newest generation of network diagramming software can scan a network, determine its topology and draw a graphic depiction.

But don't expect 100% accuracy from these discovery features, which still have some evolving to do. None of the three network design packages we evaluated was able to identify all the components of our test network. The product that came closest was our Blue Ribbon winner, Visio Enterprise 5.0 from Visio, which performed the most comprehensive - albeit most time-consuming - network discovery. It also delivered the best user interface and topped its competitors' drawing capabilities and options for exchanging files with other applications.

Securing second place in our tests was NetFormx SE 3.5 from NetFormx. A solid performer, NetFormx makes it easy to create new objects to add to your network diagram and allows you to restrict the discovery process to particular areas of your network. However, we were disappointed with the product's sparse import and export capabilities.

How we did it

We tested each package's ability to discover and diagram networks by installing the packages on identical Dell Optiplex GXi 200-MHz Pentium II PC workstations with 64M bytes of RAM, running Windows 95 and Windows NT 4.0.

We connected both workstations to a Cisco Catalyst 5500 Fast Ethernet switch that we connected to the management segment of West Virginia University's (WVU) enterprise network.

To test the discovery features, we told each program to survey the devices operating on WVU's campus network.

To test the drawing capabilities of each package, we attempted to create, from scratch, an ATM backbone network. This backbone was derived from the actual network that connects WVU main and regional campuses scattered throughout the state.

This drawing was not particularly difficult for any of these packages, but it was complex enough to stretch their muscles.

To check import and export capability, we attempted to import and export the various file types supported by each package.

Finally, NetSuite Professional Series 5.0 from NetSuite Development gets the job done, provided you work your way through a tedious installation and registration procedure. We weren't too impressed by the 5-minute discovery process we witnessed, which was unfortunately as incomplete as it was fast.

Not quite full disclosure

Before you start drawing, you need to take stock of the equipment on your network. An autodiscovery program can save you time. To find and identify the elements on your network, network diagramming software sends pings, SNMP gets, or a combination of the two. Reporting methods vary: Some programs distinguish routers, subnets and nodes in their discovery process; others simply report the number of devices and network segments discovered. The software then maps how the devices are connected.

To test proficiency, we let each package dig around on the West Virginia University enterprise network, which consists of an ATM backbone with four routers, and an FDDI backbone with eight routers. There are 159 subnets connected to the backbone network and more than 13,000 nodes.

None of these packages was able to discover our entire network. Not surprisingly, the fastest to complete the discovery process was the least accurate, and the slowest was the most accurate.

Visio Enterprise took its time mapping our network. We started the product's discovery process early in the afternoon, and it was still running seven hours later when the last of us went home. When we came in the next morning, Visio Enterprise was finished and had discovered 19 routers, 120 subnets, one FDDI ring and three token-ring networks. The router count was high because, without being told to do so, Visio Enterprise scanned and discovered devices on a neighboring network connected to our enterprise.

Launching Visio Enterprise's autodiscovery process isn't tough once you unearth the program's Advanced Discovery Agent, which is found three layers down in the menu hierarchy. We'd prefer to see Visio place this agent where it can be more easily accessed.

Visio Enterprise allows you to create multilayer diagrams using linked pages. Unfortunately, Visio Enterprise's discovery agent seemed unaware of this capability and placed all the discovered devices on a single layer of the drawing. This created an overwhelmingly complex diagram that was virtually unreadable. To reduce the clutter, we used Visio's Hyperlink function to create related drawings that allowed us to drill down into the network. Although not too taxing, the cutting and pasting we had to do to create the linked drawings was an unfortunate waste of time. It would help if Visio prompted users to request multilayer drawings before the program initiates the lengthy discovery process.

NetFormx discovered 12 routers, 71 subnets and 2,130 nodes in 1 hour and 35 minutes. Although it did not discover the complete network, that's a decent showing in a reasonable amount of time. We appreciated the level of user control that NetFormx builds into its discovery process, which is the most flexible of the three products' processes. You can opt to identify and draft the entire network, local subnets or a specific subnet, and you can choose to exclude subnets and devices from the scan process. This selective scanning feature is a real timesaver when you only need to deal with subsets of large enterprise networks.

The undisputed speed champ, NetSuite, completed its discovery process in less than 5 minutes. However, it identified only 39 segments on our enterprise and found the fewest number of devices. One reason for this poor showing may be that the version of NetSuite we tested limits its discovery process to 1,000 hosts, which left much of our test network undiscovered. According to NetSuite, the number of nodes discovered depends on the size of the NetSuite Node Pack you purchase. NetSuite sent us a 1,000-host Node Pack. However, customers can buy NetSuite packages that will discover an unlimited number of nodes. The feature sets are the same; only the number of nodes discovered varies.

Launching NetSuite's discovery process is overly complicated, we found. To run NetSuite discovery you must access the Professional Audit application, which is bundled with the company's Advanced Professional Design module. (Without a Node Pack, NetSuite's Professional Audit application cannot discover any nodes.) Once run, NetSuite's design module won't automatically create a design based on its discovery of the network. Instead, you have to execute multiple commands to transfer the discovered segments from the Audit module to the design module.

Information exchange

Though autodiscovery is helpful, it's obviously not your only source for network information. If you've created previous diagrams using another drawing package, you'll want to be able to import that data into your new diagramming program. In addition, export capabilities will enable you to share discovery data with other packages, perhaps with more capable databases or more sophisticated graphics.

Visio Enterprise's import and export capabilities are the most comprehensive, followed by those of NetSuite. NetSuite tops Visio Enterprise in one area: NetSuite can import device objects from database programs such as Microsoft's Access and FoxPro programs; it also can import from and export to Excel spreadsheet files.

Import and export functionality within NetFormx is very limited. You can import Visio projects and export network diagram elements to Excel to run simulations and perform network calculations, and that's about it.

Draw it up

Once your discovery is complete and the data imported, it's time to draw. But let's face it - network architects are rarely artists. When it comes to diagramming networks, they need intuitive, easy-to-use drawing tools and a comprehensive library of devices and network symbols.

Visio Enterprise offers extensive drawing capabilities, a large library and decent design tools. Using Visio's stencils, you can select specific network devices and drag them to your drawing. The stencil window offers a graphic preview of each device.

When you create a new graphic object, Visio Enterprise opens a dialog box that allows you to describe the device. Unfortunately, Visio Enterprise doesn't automatically add the device name to the drawing, so you have to label the device manually. The product automatically enlarges the device graphic and the text box, which makes entering device titles easier.

Visio Enterprise's Connector tool does a decent job of connecting network devices. While Visio Enterprise takes great pains to avoid running connectors through other objects on the diagram, it makes no attempt to avoid text labels. Often you have to adjust the lines to avoid a messy diagram.

NetFormx offers a decent selection of drawing tools. You can drag devices from the browser window directly into the drawing window. A description of the device, which you can edit, appears below the device. We had one complaint: NetFormx inexplicably reduces the size of the text to about seven points when you're editing an object's text, making it extremely hard to read what you're typing.

If a device does not exist in the library that ships with NetFormx, you can create your own device by basing it on an existing object. If that isn't good enough, you can create a new library element from scratch. That can be handy for newly released devices that may not have made it into the library.

Curiously, NetFormx doesn't include a save command - databases and drawings are automatically saved as projects containing all the elements of the design, including the graphics and database entries. By default, NetFormx stores these projects on the same drive partition as the main program. While protective, this feature is also restrictive. NetFormx users are sophisticated enough to decide where and when to store files, and the application should give them that opportunity.

With NetSuite, you create designs in the Advanced Professional Design module. NetSuite's graphics are less detailed than the other packages' graphics, and devices are not drawn to scale. In addition, the library browser doesn't allow you to preview graphics. NetSuite claims that library elements are not just bitmaps, but detailed simulations that behave like the devices being modeled. The intent is to prevent the user from installing an unsupported card or protocol.

NetSuite's device library is not as comprehensive as that of Visio Enterprise or NetFormx. If you can't find the desired device, you can use a generic device. However, the generic ports and configuration may be different from those of the device you are trying to model. Alternatively, you can download additional devices from NetSuite's Web site. Otherwise, NetSuite's Toolkit, which is bundled in NetSuite Professional Series 5.0, includes a utility called Foundry that lets you create your own devices from scratch.

While Visio Enterprise and NetFormx allow you to link properties after you create the connection, NetSuite allows you to link while you are specifying the connection. You must select the first device to be connected, press F5, and then select the second device. This brings up the Create Connection dialog box, in which you reselect the devices and specify the connection type. At first this process seemed awkward, but the more we used it, the more we liked that it allowed us to specify and format a link in one operation.

Up and running

Getting started with Visio Enterprise was tricky; the installer loads the complete custom installation - all 427M bytes - by default. We overrode the default choice and selected the "Typical" installation option, which installs the most commonly used components and claimed 145M bytes on our hard drive.

Installing NetFormx was a breeze. The typical installation will claim roughly 71M bytes on your hard drive.

Launching any of the NetSuite applications is a different story. You first need a license key that you must obtain from NetSuite's Web site by clicking through a series of screens and eventually entering the CD-ROM serial number, a registration ID generated by the program and address information. Once loaded, NetSuite's typical installation requires 82M bytes of hard drive space.

Documentation is critical if you plan to take advantage of the full capabilities of these complex design tools. Visio Enterprise's documentation is easy to read and helpful, but daunting. The company provides the 460-page Developing Visio Solutions, 203-page Using Visio Enterprise, and 258-page Modeling in Visio Enterprise guides.

Except for a printed 22-page NetFormx starter guide, NetFormx places all of its standard documentation on CD-ROM. A printed copy of the 297-page users guide is available, but it costs an extra $40. With a product this complex, we expect all documentation to be printed and included with the package.

NetSuite comes with three well-written volumes:

A 162-page guide for the Professional Audit module
340-page guide for the Advanced Professional Design module
A 212-page guide for the NetSuite Toolkit.

All in all, these diagramming packages will make life easier for network designers and improve the quality of network documentation. But make sure that you know the strengths and weakness of a package before you invest in its future.