As we have seen in part one of this series a fully fledged hardware based lab is going to cost in the region of £1000 and in part two we saw that going for an online rack rental will cost anywhere between $900 and $2700, so when you take into account the exam costs then we are talking about £2500-3500 for this exam. But is there another option, one to bridge the gap in online and having your own rack full of routers and switches?
Here we are going to see just how far we can go with mixing the various Cisco simulation, or simulator, software offerings that are around, and possibly extending it with real live equipment.
The options we have for software based emulation are Cisco's PacketTracer, GNS3, Cisco IOS on Unix (IOU), and Boson NetSim.
PacketTracer we should all be aware of, as its been with us through CCNA and the CCNP (but if its not familiar then it's Cisco's own router simulator software, which you can download for free from here). Its going to fall short at CCIE level though. Similarly with Boson NetSim, great for all the way up to CCNP, but again not suitable for CCIE level.
So there we have two simulators, that, although serving us well for sometime now can cut the mustard at this level. Certain things like HSRP, BGP and route maps just don't play well on simulated hardware, and they don't unfortunately offer a way to connect to real-live equipment to bridge that shortfall.
So lets move away from simulators and look at emulators, namely GNS3 and IOU.
The GNS3 simulator is great for routers, but due to the ASICs found in Cisco switches this falls short. It will take an IOS image, and can replicate a real router and all of its functions, but as you know from reading the exam topics for the CCIE, routing is only half the story (also the clue is in the title "Routing And Switching". The benefit of the GNS3 simulator is that you can connect the emulated routers to real-live switches, something we'll look at in another post.
**Update** - Please see here for how to connect GNS3 to a real switch.
GNS3 takes a little time to get used to, but with a suitably beefed up PC (or Mac, or Linux) it will run 1700s, 2600s, 2691s, 3000, 3700 and 7200 series routers and also Pix and ASA firewalls. The switching side lets it down though, and although it offers Ethernet switches, ATM switches, Frame-Relay switches and EtherSwitch routers these really don't perform anywhere near like the real thing. The downside of using GNS3 is that it can be very resource intensive, hence the need for a fairly powerful machine. On a standard machine running 8 different routers will certainly slow things down.
That said, properly breaking out GNS3 into a real-live switch does open a whole world of possibilities. With GNS3 you don't get everything you need out of the box, it's down to you to find the images needed to make it run, useful if you have a CCO login with the appropriate privileges.
The case with the lack of proper switch emulation is the same with Cisco IOU, but, and thankfully, again we can connect a cloud device to real live equipment. Support for routers is superb (as you would expect with this being Cisco's product. We have covered the basics of IOU here, and in a future post we'll cover connecting it to proper hardware switches to extend our routing labs out. IOU is much better at resource management than GNS3 and with the same number of virtual routers running on the same equipment the negative effect it will have on performance is noticably reduced, making it much better for a large scale lab.
So many people have reported excellent success preparing for the CCIE lab with a mixture of emulated and real hardware with either GNS3 (which does seem easier to get into, and certainly easier to find!). But really, at the end of the day, what is possible is not always necessarily what you want to do. Many I know will actually prefer to spend out on getting the proper hardware. But if you can buy £400 worth of switches and do the rest via either GNS3 or IOU then great! Its certainly very possible. You pocket will certainly thank you for it.
So to sum up.
- Forget PacketTracer or Boson, they really arn't up to the job.
- There really isn't a best cisco simulator software available
- If you want to go for the full hardware solution then it will match closer to the lab environment than emulated.
- Switches suck in an emulated environment.
- If you want to go for emulated/real hardware solution and your google-fu sucks then go for GNS3 (if your computer is powerful enough).
- Cisco IOU is better tuned for "standard" computers.
- Fully emulated will get you some of the way but don't rely on it to get you 100% of the way through the lab.
*Edit 23/10/2013 - Although I still say that switches suck in GNS3 and IOU, HSRP does actually work on them*