Q&A on GNS3 WorkBench v8.6

I got some great questions from Rob Methven so I thought I’d answer them here in the form of a “Q&A”.

Q. I got the Etherswitches and VPCs pinging each other no problem. However, when I do a show mac-address table on the switches, the CAM table either show up as completely empty or with just the last couple of MAC addresses. Repeated show mac-address-table show that the table gradually removes the entries until it’s empty, normally within 30 seconds. I’m using the recommended IOS for the c3725 (T10), but I’ve also tried with the T14 release and observed the same behaviour.

A. This is a known problem with dynamips and has been reported on the GNS3 Forum. I’ve asked Flàvio (maintainer of dynamips) to look into it again.

Q. RE VPCS: When I load the exercises, am I right in thinking that I have to manually configure the IP addresses on the individual VPCs? I’ve done it no problem, and saved the config so I can quickly load it, but I’m just checking that I’m not doing anything wrong!

A. Some exercises will require that the IP addresses for the VPCs, others will have pre-configured exercises. To be honest, there are a couple of places where I meant to have IPs already configured but didn’t. What happens when you load a snapshot is that the contents of the snapshot’s configs directory gets copied to the current project’s configs directory. If I remembered to put the relevant startup.vpc file in the snapshot’s configs directory then the VPCs will start with the correct addresses.

Q. When I load a snapshot for a topology, I get a message saying that the IOS image can’t be found. I get an option to choose the correct image, which is invariably the same file. The only difference that I can see is the path. The images that I can use have the full paths (C:\Users\Rob\GNS3\Images\imageName.image) to the image listed in the dialog , even though it’s in my specified “Images” folder. I can fix this by editing the topology file to point to the full path, so again, it’s not a massive issue. Just wondering if I’m doing something wrong!

A. This is a real bummer – this problem was solved back in GNS3 0.8.3 and re-introduced somewhere between v0.8.3 and v0.8.6 – and since Jeremy is now busy working on GNS3 v1.0, I’m guessing there won’t ever be a real fix for this. Unfortunately going back to GNS3 v0.8.3 is NOT an option, because that version doesn’t support he Help features and the Snapshot features that GNS3 WorkBench now relies on. If you look at the toplology.net files that are supplied in the Windows/OS X version of GNS3 you will see that there is NO path specified in the

image = c3725-adventerprisek9-mz.124-15.T10.image

lines in all the exercises and snapshots. I’ve just written a script to allow a user fix this for Linux based systems (may work on OS X) but don’t have anything for Windows yet (any Windows script writers out there wanting to take a bash script and “Windoize” it please contact me!).

What you need to do is the windows equivalent of the linux command:

find . -type f -name topology.net -exec sed -i "s#c3725-adventerprisek9-mz.124-15.T10.image#C:\full\path\to\c3725-NEWIMAGE.image#" {} \;

but I don’t know if Windows has such commands.

Q. Just show me where to donate!

A. I do this to help the community. I had at one stage thought of trying to set up a link to a charity, but it got too hard. You could of course buy my book if you think it will be useful, or sign up for SlideShark using this link where you’ll get an extra 25MB free for using the link.

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Posted in dynamips, GNS3, GNS3 WorkBench | Tagged , , , , , | 1 Comment

GNS3 WorkBench v8.6 is finally out

Executive OverviewSample3

The next version of GNS3 WorkBench is out.  You can download it several forms:

  • An entire Virtual Machine as a single blob (although split into two files 2.5G-3G in size)
  • The same Virtual Machine as individual files (in case you can’t get the big files)
  • A “self-serve” script to allow you to install everything you need to create your own Appliance on whatever flavour of Linux you like (so long it is Mint 16.0)
  • Just the WorkBench labs and exercises along with their instruction files.  These can be added to your existing Windows or OS X install of GNS3 to give you the essential elements of the WorkBench in the comfort of your own favourite Operating System.  This version is only possible because of the great work Jeremy did in fixing the Snapshot function and Instructions features in GNS3 v8.6

The Features in a Nutshell

  • Labs are now based on GNS3 Snapshots – so you don’t need to run a script to load the appropriate exercise, you can open exercises/labs from within GNS3
  • The help system is now html based, and is integrated into the Help | Instructions feature that was introduced into GNS3 v0.8.5
  • Since GNS3 now has VPCS incorporated into the Tools | VPCS menu, there is no need to load VPCS via a startup script to run labs/exercises.
  • The above three features have removed now make it possible to deliver a Windows/OS X version of GNS3 WorkBench.
  • Labs have been updated to more closely reflect the September 2013 changes to the CCNA exams.
  • Over 20 new labs/extensions to labs.  Mostly troubleshooting exercises added to tried and true labs.
  • Total of 50 different Labs/Scenarios
  • Total of approx 140 different exercises/solutions (Snapshots) shared between these labs.
  • Ability to add your own exercises – just save your own snapshots and add your own instructions.

More Details for the Nerd at Heart

When I first published GNS3 WorkBench, I had four objectives in mind:

  1. To produce a set of exercises/labs that could be loaded into GNS3
  2. To be able to present a page of instructions to accompany each exercise/lab
  3. To be able to reset the exercise/labs after use
  4. To integrate VPCS into the process

Thanks to the changes made to the Snapshot function, the Tools | VPCS option and the  and Instructions features in GNS3 v0.8.6, my objectives 2-4 above have been pretty much integrated into GNS3 (at last – thanks Jeremy).  So I’ve had to completely re-focus on what I want GNS3 WorkBench to be.

So the new GNS3 WorkBench is mostly about supplying the instructions in a much nicer web-based format, and re-working every lab to create snapshots, more instructions and VPCS startup files to fit the new format.  And while creating these, keeping in mind that I’d like to make the set of exercises/labs device independent – in other words to be able to produce a set of exercises/labs that could work on Windows or OS X.  I also wanted to add some automation to the addition of ASA and Juniper routers, so scripts to help in this regard are part of the package.  And finally, I wanted some of the Open Source extensions built into GNS3 WorkBench – like Linux running under Qemu and Vyatta routers running under Oracle VirtualBox.

And the results don’t look too bad either! (Even if I do say so myself).

Screen Shot 2014-04-07 at 11.39.38

I’ve created three flavours of GNS3 WorkBench comes this time, including an all-time-first Windows/OS X version.

Flavour #1 – The VM Appliance.

Everyone’s favourite. I built the Appliance on Linux Mint 15.0.  You can download it as a monolithic 5.6G file (in two parts because SourceForge won’t allow files larger than 5G) or as the individual VM files.  If you want a ready-made VM appliance then choose either method, the end result is exactly the same.

I built the appliance on Linux Mint v15.0 – because Mint just had the feel and features that I expect from Linux.  Like being able to right-click in a file-browser and choose “Open in Terminal” and “Open as Root“.  That’s my kind of environment.

Flavour #2 – Self-serve script.  The Bespoke Linux install.

When I was building the master copy of the Appliance I built a GNS3 environment which had copies of several routers, including Juniper, ASA and Vyatta routers as well as Microcore Linux running under Qemu.  To achieve this I had to install many applications on my copy of Linux Mint.  By to keep a record of what I had installed, I  built a script that could reproduce the environment again from a fresh Linux install – so that script became the second way to install GNS3 WorkBench.  And I used it over and over to test fresh copies of GNS3 WB.  In fact, I created the master copy of the Appliance by running my script on a fresh install of Linux Mint 15.0.

The self-serve script allows you to choose various features that you might want to add to GNS3, like installing Qemu, Wireshark and even downloading some prepared Qemu and VirtualBox Images.  Originally it was designed and tested on Linux Mint 15.0 but unfortunately, Mint 15.0 is based on Ubuntu Raring…. “unfortunately support for raring has been dropped from Launchpad (the peril of a 3rd party system!), as support ended in January.” (http://forum.gns3.net/topic6426-28.html) Which means that my self-serve install suddenly stopped working about March 28 – the day after I had finalised my script! However, the good news is that it seems that the script works OK on Linux Mint 16.0 (32 bit), and that there might be some changes afoot to give the GNS3 repository a more permanent home which will make the script work agin on Mint 15 (and probably Ubuntu Raring as well).

The install script carries out the following tasks:

  • Updates your Linux OS with the latest patches and adds the repository where GNS3 resides.
  • Downloads and installs the scripts to enable support for ASA and Juniper
  • If you have downloaded the ASA image, it will be prepared for use in GNS3
  • Downloads and installs the following:
    • NIO tap adapter
    • Qemu
    • open-ssh server
    • CPU Limit utility
    • Oracle VirtualBox emulator
    • Wireshark
    • terminal applications Xterm, PuTTY and Konsole
    • dynamips
    • GNS3
    • the Virtual PC Simulator (VPCS)
    • a specially prepared Qemu freeBSD image for use with Juniper routers
  • if you have Juniper image available, the script then takes you through the tedious Juniper install process.
  • Downloads a collection of Virtual Box VMs that are used in the GNS3 WorkBench
  • Downloads the GNS3 WorkBench exercises and sets up the default settings in GNS3 and your desktop
  • Fixes file permissions so you can run the labs smoothly

The script is pretty rough – very little error checking, and if you end up with a wrong version of something or some application fails to install, then… well… you are welcome to re-write the script!

Flavour #3 – Windows/OS X Install.

Not exactly the full GNS3 WorkBench (it will not put pretty icons on your desktop) but so long as you have GNS3 installed along with Qemu and Virtual Box, you will get all the exercises/labs – except you are on your own to make the Juniper/ASA labs work.

So good luck. Let me know if you have any problems – rednectar.chris is my gmail account.

Chris Welsh

Posted in CCNA, Certifications, Cisco, dynamips, GNS3, GNS3 WorkBench, ICND1, ICND2, Labs, Mac OS X, Microsoft, Routing, Wireshark | Tagged , | 2 Comments

Using an iPad to improve Webex presentations – especially the Whiteboard

I had to do some Webex presentations recently – and I found the Webex interface clunky and dated – especially the annotation functions and the Whiteboard function.  Here is how I managed to at least spruce up the Whiteboard function using a free iPad app and a cheap application on my laptop.

Firstly, understand that Webex is an ancient online video collaboration tool with enough basic features to allow you to present PowerPoint slides (so long as they are saved in the correct format) to a live online audience who either listen online or over the telephone after signing in to the meeting online.  When you present slides in Webex, your PowerPoint slides loose all animation and the best annotation tool available is a pointer that displays your name. 


Fig 1: Webex Interface. The best annotation tool available is a pointer that displays your name.

While presenting your PowerPoint slides, you can click on part of your slide to make you pointer visible to the other participants.  The presenter also has the power to grant other meeting participants privileges to also click their pointers on the screen, or use the basic annotation tools which consist of typing text, drawing lines and boxes and a highlighter/scribbler.  However, it is particularly the annotation tools that fall down.  You can click on your slide and drag to draw a line, but neither you or any other participant sees the line until you lift your mouse/finger to finish the line.  And once drawn, you can’t move it, change its colour or direction.  Copy and paste the line to another part of the screen? Not supported.  Typing text is even more frustrating – you create a text box and begin typing.  Now even ancient NetMeeting (think Windows 95) had the ability to present the text you were typing in real time to the other participants in the meeting, but not Webex – oh no, with Webex, the typing does not appear on the other participants’ screens until you click away from the text.  Need to change the text, correct a spelling mistake? Increase the font size?  Too bad – Webex does not allow any of that.  The most useful tool is the eraser, which at least allows you to delete an entire block of text or object in a single click.  Oops! Wrong one deleted?  Too bad there is no “undo”.


Fig 2: Even ancient NetMeeting (think Windows 95) had the ability to present the text you were typing in real time to the other participants in the meeting

The Webex Whiteboard function gives you exactly the same ugly animation tools but on a blank canvas.  And it was this lack of functionality that made me think of using a shared whiteboard drawing tool that I might be able to access from my iPad.

My search for a decent “whiteboard” application let me down a couple of paths.  At first I thought I’d found the perfect answer – http://awwapp.com/draw.html – I could draw on my iPad with simple tools and share this content with anyone by sending them a link like http://awwapp.com/draw.html#47e146d0.  And since Webex has a “Share Web Content” option I thought this would be ideal – I could share this webpage just like the whiteboard and presentations, but be doing the drawing on my iPad.


Fig 3: At first I thought I’d found the perfect answer - http://awwapp.com/draw.html

But of course my first mistake was that I expected it to work.  Sure – Webex lets you share a webpage like http://rednectar.net, but NOT a page like http://awwapp.com/draw.html#47e146d0 – the hosting computer sees “404-not found”, while remote PC clients see a blank whiteboard.  Remote iPad clients using the iPad Webex app see an informative message saying “The content of the presentation is not supported” – or translated “You should have more sense than to expect Webex to support html content on the iPad – after all, the iPad has only been around for four years“.  (The iPad Webex app can’t even display pages like http://cisco.com if shared on Webex from another computer).

Result of sharing awwapp.com

Fig 4: My first mistake was that I expected the Webex “Share Webpage” to work.  Sure – Webex lets you share a webpage like http://rednectar.net, but NOT a page like http://awwapp.com/draw.html#47e146d0 – the hosting computer sees “404-not found”

Next stop – share my browser instead.  I’d have my iPad displaying the shared awwapp page, and my Webex host PC displaying the same page – which was shared over Webex.  Now the result was “successful” but less than “satisfactory”. The content shared OK, but the drawing was a little laggy – and well, the web based app had less drawing options than Webex – but at a pinch – if you really wanted to draw on your iPad and display in your Webex meeting, you could.

Undaunted, I thought I’d explore the iPad Webex app a little further, and passed the host role to where I was logged in on my iPad to see if the animation tools and Whiteboard would be better on the iPad.  As it turns out, they are not only “not better” they are “non-existant”.  The iPad Webex app simply does not even have the most basic of annotation tools available.  In fact it is worse than bad – the iPad can’t even take control of an already uploaded presentation – all it can do is share content (not apps – so I couldn’t share a whiteboard app).  And when you do share a PowerPoint presentation, it gets turned into a continuous scrolling pdf file, so it not only looses animations, gets reformatted so that only about 90% of the slide fits on the screen and, it looses the ability to move through a “page” at a time.  This lack of pagination means that if you are presenting from the iPad, be prepared to wait minutes for your remote screens to catch up if you scroll through a lot of pages quickly.  The one good thing about sharing from the iPad is that it does have a very neat and responsive “laser pointer” that shows up on the participants screen when you touch your finger on the screen.

Webex On iPad

Fig 5: Only about 90% of the slide fits on the screen using the Webex iPad app, but it does have a very neat and responsive “laser pointer”

So I gave up on the iPad Webex app. I had to find a better approach.  I began thinking “Is there a way to display my iPad screen on my computer?” Because if I could do that, I’d be able to share the app that did that on Webex.  And I know there is a plethora of drawing applications for the iPad.

Enter “Reflector“.  What a great little app this turned out to be.   After trialling it for a few minutes, I forked out the $12.99 and bought it.  I have a Mac, but it is available for Windows as well.  And it turns your computer into an Airplay device – and of course it is dead easy to send the screen of your iPad to any Airplay device (so long as both are connected to the same wireless network).

So now I can tell Webex to share my Reflector application, and my audience sees my iPad screen – and if I display a whiteboard application on my iPad, my audience can see it – there is a bit of a lag, so it is not as good as if Webex had have provided the tools their customers deserve, but it is still streets ahead of the native Webex whiteboard – so long as you can find a good Whiteboard app for your iPad.  I found several, and have a summary of them at the end of this article.


Fig 6: Now I can tell Webex to share my Reflector application, and my audience sees my iPad screen

An added bonus is that I can now use Slideshark on my iPad to present my slides (including animations) – just like I do in a face to face class. SlideShark also has some basic annotation tools – not brilliant, but easier to use than Webex because they are finger/stylus controlled on the iPad rather than mouse controlled on your computer.  The disadvantage of this approach as apposed to uploading your PowerPoint slides to Webex is that there is a longer lag between switching slides than there is if the slides are uploaded – but at least your slide animations will work!  SlideShark also has a feature where you can hold down your finger on a slide to produce a moving “laser dot” pointer – but to be honest I found the lag so bad I didn’t use it.

I’m sure there are better web based lesson presentation tools out there, (GoToMeeting?) but I have to use the tools that my customer wants, and the customer that wants me to use Webex is not going to want to use anything else, so I’m stuck with Webex.  So my recommendation for using Webex are:

  • Use a computer rather than an iPad to present slides.
  • Upload your slides and any other content you want to share before the meeting starts.
  • Use Webex to present slides unless you have slides that have animations.
  • Buy Reflector so you can send content from your iPad to your computer via AirPlay (assumes you have access to a wireless network and an iPad of course)
  • Find a good whiteboard/drawing app for your iPad, and use it via the shared “Reflector” application to present whiteboard materials.

Here’s the iPad whiteboard/drawing applications I tried.  You may find something better, but you can see the features that I wanted listed in the table.  I’ll do a more thorough review of the these apps in a future post.


Feature/App InkPad ShowMe Jot!Free Vittle Free Educreations WB Mojo







Simple UI







Realtime Typing

Edit Text




Snap to grid

Select and move





Multiple Boards



No Adds

ShowMe has the closest feel to a real whiteboard.  A good selection of colours a single tap away, and flicking between multiple whiteboards is easy – unless you have too many of them.  Apart

InkPad is quite powerful, but typing text and drawing shapes is clumsy – you have to change tools after drawing a shape or text if you want to resize it – once you get used to it is pretty good if you want to work with shapes – so long as you don’t want to resize them.  It has support for multiple drawings, but you have to return to a gallery page to change drawings.  I’ve used it to produce semi-animated content where I fill and empty shapes to show how flash memory works.  Inkpad takes a bit of getting used to, but is quite powerful once you are.

Jot!Free has adds, and no amount of cajoling would let me even pay for an upgraded version – the link from the free app didn’t work.  However, I guess if you pay the $5.49, you’d loose the adds.  You have to know the secret code (tap two fingers) to be able to add text, but doing so is easy.  And line or text can be easily moved about or deleted by holding down a finger on the object/text

Vittle Free has by far the most awesome resize feature.  You use a tool to select an area by dragging your finger around, and you can then either move, rotate or resize the selected portion.  The paid for version ($8.49) probably has more features, but the free version wasn’t bad.

Educreations is also a great app – and free.  It has a scroll up/down function, but no zoom – so it is possible to scroll your work off the screen, and can be a bit hard to find it again.  Its text writing and moving capabilities are great, but you can’t cut or move any drawing lines.  Lines are of fixed size – just like a whiteboard, so to me that’s not a problem.  Having a few more feat

WB Mojo is the only drawing app I paid money for – a whole $1.99.  But it has a powerful set of features as well as being able to do simple drawing stuff easily enough.

So if you have to use Webex, and want to use some of the features of your iPad, there is an answer, use the Reflections app on your computer, and send the output of your iPad to your computer screen using AirPlay.  By sharing your Reflections app on Webex, people can see whatever you display on the iPad.

Happy Webexing


Posted in Webex | Tagged , , , , , , , , , , , | 2 Comments

What is 100Base-Tx and 1000Base-TX

I came across a question in the Cisco Learning Network which highlighted a source of confusion that many people have.

Call me pedantic, but I thought I’d set the record straight – and let you know that when people refer to 1000Base-TX, they are PROBABLY referring to the IEEE 1000BASE-T standard. NOT the TIA (the people who set cabling standards) version of the standard which they cleverly called “1000BASE-TX”, and “standardised” it as ANSI/TIA-854:

“A Full Duplex Ethernet Physical Layer Specification for 1000Mbit/s (1000BASE-TX) Operating over Category 6 Balanced Twisted-Pair Cabling,” published in March 2001, provides a data rate of 1000 Megabits/second, similar to the IEEE 802.3ab Gigabit Ethernet standard. The main difference is that it requires category 6 cabling instead of category 5e cabling.  http://www.leviton.com/OA_HTML/ibcGetAttachment.jsp?cItemId=22256&label=IBE&appName=IBE

The TIA were banking on the price of the 1000BASE-TX transceivers falling, and therefore justifying selling people more expensive Category 6 cable rather than Cat5e.  I’m afraid this is one of those things that get my goat up – Why would you run Category 6 cabling to the desktop when category 5 (the IEEE standard says 5, the TIA say 5e) is more appropriate?  Do you REALY believe you will need 10Gb/s to those desktops in the life of the building?  Category 6 is soooo much harder to terminate that you probably end up with a sub-cat5 cabling system anyway even after paying all that money.

But I digress – what I really wanted to discuss is that the Ethernet standards are set by the IEEE, and a little history will help.  All quotes are from the freely downloadable IEEE standards for 802.3 Ethernet

In the beginning was 10BASE5. The “IEEE 802.3 Physical Layer specification for a 10 Mb/s CSMA/CD local area network over coaxial cable (i.e., thicknet). (See IEEE Std 802.3, Clause 8.)”

Later came 10BASE-T. The “IEEE 802.3 Physical Layer specification for a 10 Mb/s CSMA/CD local area network over two pairs of twisted-pair telephone wire. (See IEEE Std 802.3, Clause 14.)”

Note that there is no such standard as 10BASE-TX.  Note also that the IEEE specifies the cabling specifications as nBASEyy – the BASE is in ALL CAPS.  I don’t know why – especially when you think that BASE refers to “Baseband”.  IEEE thing I guess.

So the T is for “Twisted Pair”.  Fair enough.  So why is there both a 100BASE-T and a 100BASE-TX specification?

The standards spell it out:

100BASE-T is the “IEEE 802.3 Physical Layer specification for a 100 Mb/s CSMA/CD local area network. (See IEEE Std 802.3, Clause 22 and Clause 28.)”  A closer look at Clause 21 gives more insight: “100BASE-T uses the existing IEEE 802.3 MAC layer interface, connected through a Media-Independent Interface layer to a Physical Layer entity (PHY) sublayer such as 100BASE-T4, 100BASE-TX, or 100BASE-FX.”

Curious to note that 100BASE-FX is included, so we can’t assume that the “T” in 100BASE-T has anything to do with “twisted pair”

100BASE-TX is the “Physical Layer specification for a 100 Mb/s CSMA/CD local area net- work over two pairs of Category 5 twisted-pair cabling. (See IEEE Std 802.3, Clause 24 and Clause 25.) ” but it is not the ONLY twisted pair cabling standard for 100BASE-T.

100BASE-T4 is the “Physical Layer specification for a 100 Mb/s CSMA/CD local area net- work over four pairs of Category 3, 4, and 5 twisted-pair cabling. (See IEEE Std 802.3 Clause 23.)”.  However, very few vendors produced equipment to match this standard.

Now, at the same time at the 100Mb/s standards were released, the auto-negotiation specs were published. Or more precisely, “Physical Layer link signaling for 10 Mb/s and 100 Mb/s Auto-Negotiation on twisted pair”.   Mostly this was implemented as negotiation of 10BASE-T/100BASE-TX – although the standard specifies the “Auto-Negoti- ation function also provides a Parallel Detection function to allow 10BASE-T, 100BASE-TX, and 100BASE-T4 compatible devices to be recognized, even though they may not provide Auto-Negotiation”

Not surprisingly, vendors took to abbreviating the auto-speed negotiated Ethernet as 10/100BASE-T or 10/100BASE-TX – or often as 10/100Base-TX.

When the 1000BASE-T gigabit “Physical Layer specification for a 1000 Mb/s CSMA/CD LAN using four pairs of Category 5 balanced copper cabling. (See IEEE Std 802.3, Clause 40.)” case out, it was added to the auto-negotiation clause and vendors began referring to 10/100/1000Base-TX.

But there is no IEEE 1000BASE-TX standard


Posted in 1000BASE-T, 1000BASE-TX, 100BASE-T, 100BASE-TX, 802.3, Ethernet, IEEE | 3 Comments

Big Data Defined

OK – I stole it. But it was too good not to share:

Big data defined:

Big data is like teenage sex:

Everybody talks about it

Nobody really knows how to do it

Everyone thinks everybody else is doing it..

so everyone claims they are doing it.!

If anyone knows who I should attribute this to – let me know.  The earliest reference  (although not complete) I could find was here.

Posted in big data, blog | Leave a comment

FCoE versus FC Farce

RedNectar Chris Welsh:

Tony Bourke has just posted a great leveller to shed some illumination on the flawed methods used by the Evaluator Group in their report “Comparing Enterprise Storage Networking Options FC vs. FCoE Lab Validation”

Originally posted on The Data Center Overlords:

Updates 2/6/2014:

  • @JohnKohler noticed that the UCS Manager screenshot used (see below) is from a UCS Emulator, not any system they used for testing.
  • Evaluator Group promises answers to questions that both I and Dave Alexander (@ucs_dave) have brought up.

On my way back from South America/Antarctica, I was pointed to a bake-off/performance test commissioned by Brocade and performed by a company called Evaluator Group. It compared the performance of edge FCoE (non-multi-hop FCoE) to native 16 Gbit FC. The FCoE test was done on a Cisco UCS blade system connecting to a Brocade switch, and the FC was done on an HP…

View original 2,099 more words

Posted in Cisco, Data Center, Data Centre, UCS | Leave a comment

How to add Instructions to GNS3

Have you clicked the new menu item - Help | Instructions on GNS3?  This article explains how to make use of this feature, as well as point out some pitfalls along the way. 

Getting Started

If you want a page of instructions to appear when you click Help | Instructions in GNS3, this is what you need to do.

  1. Build a topology and make sure you have saved it.  Let’s assume you built a topology called Project_Name and saved it in the default location off you Projects directory.
  2. Create a new directory called instructions (case sensitive) off your Project_Name directory.
  3. In this directory, create a file beginning with the letters  instructions (case sensitive) – it could be  instructions.txt or  instructions.doc or even just  instructions - but for this example, let’s assume it is  instructions.html. [Caveat: The file you create MUST have a default application that can open it on your operating system.  If your OS can't open .doc files, or files with no extension at all, there is no point naming your file instructions.doc or instructions - see Pitfall#2]
  1. Now you’ll have to write some instructions appropriate to your topology.  If this is a profiling topology, you might want to include instructions on how to start the routers and what to check in the configurations.  But if you want to create a professional looking web-page, you will probably use one of the following three methods:

Method 1: Keep it simple

There is no reason why you can’t put some simple plain text in the document.  You don’t need to be an html guru to create some simple instructions.  Just look at this example taken from the old version of GNS3 WorkBench.

* You should see another window where the GNS3 program is running.           *
* In that window, click on the green "Start" icon - looks like a "Play" icon.*
* When all the devices have started, click on the black "Console" icon (to   *
* left on the "Play" icon). Your terminal session(s) will start in tabs next *
* to this screen.                                                            *

This lab is designed to explore the features of the VPCs program.  You should 
see the tab for the VPCs program next to this screen.

Click on that tab, and explore the options that are presented to you.

This configuration can be very useful for exploring other features too.R1 is set up as an IPv4 DHCP server and does IPv4 NAT
R2 is set up as a DNS server, and also does IPv4 NAT to the internet. For 
this to work, your first adapter from the virtual machine running
GNS3 WorkBench must be connected to a DHCP server. (Assuming original 
GNS3 WorkBench configuration)

Nothing here but plain text – but it will appear just fine in a web-page so long as you called it instructions.html - perhaps not with exactly the same font or character spacing – but for that you’ll need to explore Method 2: html text.

Method 2:  html text

To ensure that your text is nicely formatted, you might want to pack the preceding page with some html tags – nothing fancy – the following would do. Just add some html tags around the text:

* You should see another window where the GNS3 program is running.           *
* In that window, click on the green "Start" icon - looks like a "Play" icon.*
GNS3 WorkBench must be connected to a DHCP server. (Assuming original 
GNS3 WorkBench configuration)

There you go – just a few <xxx> </xxx> tags around your text and you have some html formatted text.  Of course you already understand that multiple spaces are insignificant in html unless enclosed in a <pre>…</pre> block, but to make more significant pages, you will need to either become an html encoding expert, or use an html editor.

Method 3: html editor

There are hundreds of html editors around – you can even use MS Word as an html editor.  But for my purposes of trying to create a simple and clean (=still decipherable in a text editor) web pages for GNS3 WorkBench, I used the free, html online editor at quackit.com, after starting with one of their free templates.

The template I chose used frames, and the website provides an excellent tutorial about frames, so it wasn’t hard to adapt the page to display a copy of the topology.png screenshot (that is automatically created when you save a GNS3 topology) into the instructions.  Pretty soon (an hour or two) I had instructions pages that looked like this:

GNS3Wb Help Screen0 GNS3Wb Help Screen1

And I had built myself a template that I could use over and over for other exercises too.

But if editing html is not your cup of tea – you may prefer to create your instructions page on an external website, such as WordPress.com, then redirect the instructions page to your public online webpage(s).

Method 4:Redirect to a public webpage

For this example, I’ll show you how I make René Molenaar’s GNS3-Vault exercises appear when you load one of his exercises in GNS3 WorkBench. In this case, all I do is create the instructions.html document (as described above) and place the following text in the document – in this case, the exercise was the PPPoE exercise:

<meta http-equiv="REFRESH" content="0;url=http://gns3vault.com/HDLC-PPP/ppp-over-ethernet-pppoe.html">

Note that all I do is use the meta http-equiv expression to make the page re-direct to the appropriate gns3vault.com page.  That’s it!  Of course, you will have to then create you sexy webpage at the site you re-direct to, but at least your target site will probably give you the tools and templates you need to create a smashing help page for GNS3!


There are a couple of things to watch out for when creating your glorious instructions.

Pitfall #1: Multiple files beginning with the letters instructions.

GNS3 (v.8.6) doesn’t actually look for files like instructions.doc or instructions.html.  Instead it looks first in the Project_Name directory for a file beginning with instructions. (note the . is included in the name).  So if you have both instructions.html and instructions.jpg in your Project_Name directory – you have a random chance of getting one or the other when you click on Help | Instructions.

If no files beginning with instructions. exist in your Project_Name directory, then GNS3 looks to see if you have a directory  called instructions in your Project_Name directory.  If you followed my instructions above, you should have.  However, GNS3 now goes through the same process in the  instructions directory, and again, if you have multiple files beginning with instructions. you will have the same problem.

I first discovered this pitfall when I was editing a file called instructions.html in Open Office.  I dragged a graphic into the document which Open Office kindly reproduced for me in the same directory as instructions.html and called it instructions_some_random_number.jpg – and you can guess what happened when I clicked on Help | Instructions - I got the .jpg appearing, but NOT the file I wanted.

Moral #1: Always create a directory called instructions in which you place your instructions.html file, and make sure your .html file does not have any dependants/links to files beginning with instructions.

Pitfall #2: No default application for your instructions file

If you decide to call your instructions file simple instructions, then there is a good chance that your operating system can’t open the file, even if it exists – simply because Windows doesn’t like opening files without extensions.  Similarly, if you call it instructions.doc and copy it to a system that does not understand what .doc files are, it will not open the file.

Moral #2: Always call your file instructions.html because there will always be a default application that will open .html files.

Pitfall #3: Your instructions file gets changed

Remember that if you decide to call your instructions file instructions.txt, then the default application to open this file is a text editor.  So if you are creating the file to be used in a shared environment, then anyone who access Help | Instructions can change your file.  If, of course you are using the feature to document your profiles topology, you might want to be able to edit the file, and perhaps no-one else has access, or you have password protected the file.

 Moral #3: If you want to protect your instructions, use instructions.html.  If you want to use the instructions file to keep documentation about a topology, use and editable format suitable to your OS – such as instructions.docx  - but remember that if this topology is shared, someone else may be able to edit and change it, so password protections might be a good idea.


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