The Case for Network Emulators

In the near future, Cisco IOS will no longer run on the Dynamips emulator. Although a lot of people are using Dynamips for learning and study, it’s also a tool used in many large companies to create test networks, and build proof of concept testing. A like the first rule of the Fight Club, no one is talking about it.

It’s time to start a conversation with your Cisco Account Manager, and for larger customers to demand that Cisco provide emulators for IOS, NXOS and ASA platforms. The same argument also applies for Juniper and HP Networking since both companies also have emulators of the Network OS’s internally today.

Test Benching and Asset Dilemma

Large companies often have a policy of purchasing preproduction network equipment. That is, for every piece of equipment in the network, a spare set is also bought for a lab environment so that configuration and upgrades can be tested. For mature equipment, we can often build test environments using older kit as it rotates out of deployment but when it comes to adoption of new equipment we have a much bigger problem.

The first purchase order of a new piece of equipment must include the test lab as well. So a purchase of two Nexus 7010 would become a purchase order for four Nexus 7010 plus modules, software etc. Unsurprisingly, this means that adoption of new technology requires a large and very well funded project and these don’t happen often, and currently not at all.

Operational Handover

Another headache to adopting new technology is that Operational Teams now have the ability to refuse to accept new technology into their portfolio until certain criteria are met. A key criteria is that skills and training must be provided for new technologies. For a networking team of fifteen people, you are talking about really serious money not just for training courses but for time lost while people are attending.

Access to the an emulator can solve this problem by allowing for internal “train the trainer” programs and providing access to a system where Ops Staff can validate their knowledge and build confidence.

Confident Engineers are creating value

The level of confidence in a solution or product is key to making the most of an asset. In certain ways, this has been the greatest success of the Cisco’s training programs. Engineers who believe that they have the skills will attempt to use them, mostly successfully. This leads to good outcomes for customers who are making value out of their networking assets.

Customers who don’t understand, or not confident in configuring their Network, will end up overspending on WAN bandwidth, or more switches, or bigger switches. Perhaps your staff will be afraid to make configuration changes for fear of unintended consequences.

Access to an emulator can help to build this confidence and engineers can deliver good outcomes to the business.

Change Control and Risk Management

The advent of change control to reduce risk of network changes means that engineers get limited time to work on live systems. In large companies, we must submit change requests that attempt to quantify risk. For many network changes we do not have high levels of confidence without test units, or an emulator to prepare the configuration changes.

In many companies, the engineer must prepare the entire configuration process without access to any box. If a deviation is found then the change must be abandoned. When planning longer and more complex changes, it’s very valuable to be able to test specific features or even the entire network to KNOW that it will work as planned. Meeting business goals is simple enough, do what you say you will – and be reliable.

The emulators exist already.

It’s my understanding that emulators exist for all platforms including NX-OS, IOS and ASA. So far, Cisco has released some emulators to customers who specifically asked for them. Those customers are large and aggressive and are able to force Cisco into a given direction. It’s also probably that business who have tightly bound their futures to Cisco might also get preferential access. gns-3-0.7-1.jpg

Either way, the emulators exist and are in use inside and outside Cisco. Why not make them generally available ?

And the smaller networking vendors have their own versions. They could make a significant impact on the market by releasing their emulators.

The Limitations of Emulators

Obviously, an emulator is not a perfect test bench tool. It’s doesn’t accurately represent a comprehensive test of all components,but if you have tested your configuration, or rehearsed the change, then you can rapidly move to resolving the hardware problem since your confidence on the software is much higher.

Consider a Nexus 7K with M series modules. Certain commands are specific to this module, and other features are tied to hardware specific isssues. For example, consider creating an EtherChannel on two different modules that have different hardware QoS which requires additional commands (no mls qos channel-consistency ) to suppress the QoS consistency check. It’s unreasonable to expect the emulator to detect this, and the the user should understand and comprehend the limitations of the emulator.

Casting an Eye at VMware

Many companies have large labs of VMware, used specifically to test MS Windows desktops and servers. This has had the effect of massively growing the Windows market. It’s Paul Maritz, VMware CEO, who stood in front of an audience and apologised for the growth of Microsoft servers in customers’ data centres. Put simply, because Windows Administrators could test and validate (and some other stuff around better deployment etc) they were able to accelerate the use of technology and grow the market. Microsoft sales of Windows Server has grown substantially as the virtualisation market has grown.

The EtherealMind View

So why don’t we have official emulators today ? We have emulators for Cisco (Dynamips/Dynagen/GNS3 ) and JunOS (Olive) that have a sort of unofficial blessing, not supported but tolerated it seem clear that they are very popular, well used and a vital part of knowledge development and learning. So why are the vendors not delivering an emulators to their customers ? If there is so much value to both vendors and customers, surely they have already considered this.

The Legal Department

One problem is the Legal Department. Lawyers are not focussed on customers they are focussed on shareholders and protecting their investments. And the lawyers are probably scared of copyright law or patent laws – the bane of of the technology industry. Additionally, once a vendor endorses and releases an emulator, at least some resources will be needed to support and develop it and that costs money. Yet, all the vendors have huge profit margins, and have equally as much to gain in terms of the overall market growing in total size. So the money issue is really down to which department is going to fund something that will take three to five years to make a return, and be hard to measure. Of course, I would point out the Cisco’s Training Program took at least five years to deliver financial benefits to Cisco, but no one thinks about long term growth any more.

Lack of Qualified People

I constantly hear about the lack of qualified and skilled people. In fact much of Cloud Computing is a reaction to the lack of resources and attempting to reduce the cost of those resources. Access to tools will create more skills and more growth.

Time to Ask your Account Manager

It’s time for customers and resellers to start demanding that vendors make emulators available. If enough customers ask, demand, insist, request and generally make the issue a priority, then the vendors will be forced to act.

It’s time to ask your Account Manager, Sales Engineer to put in the feature request. It’s time to ask the Product Managers at briefings and launches. It’s time to blog and tweet about wanting an emulator that helps you get your job done. It’s time to get other people to join in requesting and demanding tools that can help you get the job done.

I have, and now it’s your turn.

  • Brannen

    Preach it!

  • Skybaba

    Couldn’t agree more.
    I remember when people needed all sorts of hacks to get CallManager 4 working on VMware.
    But the story has changed in the newer versions. CUCM can now be installed in VMWare without all the headaches.
    Cisco obviously won’t support it, but it’s great for lab and setting up environments that would mirror production.

  • Colin

    F5 is a good example of this. LTM VE is brilliant for lab/test/dev work. It’s just a pity ASM can’t be used in it yet. And it’s annoying they’ve tried to make it VMware specific so far.

    Vyatta’s virtual editions run well on pretty much any virtualisation platform.

    I like diversity but if Juniper or Cisco was to beat one or the other to market with a fully supported emulation platform they would be the vendor I’d give preference to and the lions share of future purchases.

  • Blake Erickson

    I couldn’t agree more. Thanks for the great post and I’ll be pushing for this too!

  • shivlu jain

    You are absolutely right. Even for the new CCIE labs, everything would be on IOS-XR or NX.

  • Calin

    Even if I (and others) agree with you, knowing Cisco’s way of doing business, I don’t think that they will allocate time, money and efforts to develop and sustain such a product. As you said, maybe for some big corporation that can influence their business, but not for end (home) users.
    For the rest of us the only feasible story would be that such a product (developed for corporation) to leak out and to be available on the market. Of course this would be unsupported. It’s too early to discuss about the legal point of using such a product..:)

  • anon

    It’s disappointing to see how vendors expect their customers to set up testbed networks, practically duplicating the production networks and therefore (surprise) buying double the amount of network devices.
    Not having a testbed network makes a good excuse for the vendor’s support service to slow down the progress of tickets.

  • andrewkthx

    I don’t exactly if there are any limitations but you can run ios 15 on dynamips but only with mainline 7200 platform

  • Alex S

    I am not sure if those companies would really require to invest substantial amount of money into developing virtualisation and virtualised products if they already have some for their internal purposes. And I bet those are not just some volunteer employees’ past-time activities. Some money – yes, for distribution and support, but not development.

  • http://www.PeaceAfrique.Org J. Julu

    Hey Greg,

    You are just too right:

    “Itís time to start a conversation with your Cisco Account Manager, and for larger customers to demand that Cisco provide emulators for IOS, NXOS and ASA platforms.”

    You are a 1000 times right buddy! I agree with you a million times!

    Keep it up and we support your cause!

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  • Anonymous

    Hey Greg, IosOnUnix is leaked out Cisco last monday, check it out!

    It’s on torrent…

    Jeremy Gladdis is suiciding his certifications on it!

    Try it out, the installation is a little messy because of libraries, but you can run a hundred of routers on a simple laptop!

    goodbye dynamips!


  • Oleg

    I think it’s not that simple. Big clients can already have it or will simply buy some stuff for the lab (budget is big). Nobody cares about small enterprise. Here is my vision for those who care :)

    Hope it’s ok to share.

  • john harrington

    I think Arista are leading the way here. You can download EOS as a VM (if you’re a customer), and they show you how to install on all the major hypervisors.

  • Paul Stewart

    This article is more than two years old, but still as relevant as the day it was written. I think the legal teams need realigned with organizational goals. It is ridiculous that customers may need to purchase 7 figures worth of lag gear and keep maintenance on it for learning/poc/change management. Nothin will change until someone starts winning market share by helping their customers in this way.