The Cisco CCNA certification is a great way of starting a career path in networking. With the CCNA under your belt you will have some great practical knowledge of how networks operate and the different types of hardware and technologies that drive them.

If you are studying for the CCNA you want to ideally be able to practice configurations that you come across in your course material, to do this you have one of two options. You can either buy some old Cisco routers and switches from eBay and setup your own home lab environment or you can use some virtual lab software like the network visualizer 6.0. The first option can get expensive, especially if you want to practice some of the more advanced configurations where you need to multiple routers and switches. The second option on the other hand is a lot cheaper, a lot easier and takes up a lot less room!

With the CCNA Network Visualiser you can put a complex network together in a matter of minutes; it uses a simple drag interface with single buttons to add each device. The list of devices you can add are:

• Host PC
• 2621 Router
• 2811 Router
• 1900 Switch
• 2950 Switch
• 2960 Switch
• 3550 Switch
• 3560 Switch

The interfaces on the devices vary but generally you will be using the Fast Ethernet and Serial interfaces to link your network together.

There is no real limit to how many devices you can add so you can technically create some very large networks! When you click on a device you will presented with a larger view of the device and you can then click an interface to connect it up to another device. The level of detail is more than sufficient for the CCNA objectives. For example clicking a serial device will prompt you for whether you want to have it as a DTE or DCE device, depending which you choose you might have to provide clocking in your configuration.

If you are adding hosts you can assign them a static ip address and bring up a command prompt to test connectivity between hosts. The only working commands for the command prompt that I could find to use were ping and telnet. In all fairness these are the only two that you will really to test connectivity in your network.

Configuring the devices is a simple as double clicking them to bring up the console window. The console window will look and act just like a real Cisco router. You are able to use the function shortcuts (like CTRL+A to go to the start of the line) and typing a ? will bring up a list of available commands.

Like I said, configuring the devices is exactly the same as it would be with a real Cisco device. You can setup telnet access and configure it from another router or from a device; you can change hostnames and perform basic router changes.

But the stuff you’re really going to want to do is configuring routing protocols like RIP, OSPF and EIGRP. Providing you configure all your devices correctly these routing protocols will work and propagate routing tables throughout the network. The same thing goes for setting up vlans and vlan routing between devices, if they are configured properly they will operate just as they would in a normal network.

Sadly there are a few commands that you might come across that you want to try out but can’t even though they are covered in the CCNA objectives. The ones I found were changing the encapsulation type on a VLAN trunk link, it will not allow you and will come up with ‘Unknown Command’ (Even though if you use the ? it will show you the command is there!). You will also not be able to use the crypto command to setup SSH access. For the most part though you should be able to complete all the test labs you need for the CCNA exam – basic router commands, routing protocols, vlans, spanning-tree, access-lists, nat, WAN (Frame relay) and ipv6. Even though every single command is listed using the ?, you will not be able to use a lot of them; only the ones covered in the ccna objectives.

Summary – Overall this is a great little piece of software, it allows you to quickly design and configure networks of all sizes, you can add some pretty scalable configurations in here with as many devices as you want. 95% of what you need for the CCNA objectives are covered with the commands you can use here. However if wanted to play around with other commands or for those that are covered in the CCNP you will struggle with this. But for the CCNA this is perfect and could save you a lot of time, space and money.

Check out the CCNA Network Visualizer 6.0 at the official routersim homepage.