203-Bad number of parameters (1 with min/max=2/2)

I received a couple of messages from people who had trouble loading some of the labs I built in GNS3, this is the error they reported:

203-Bad number of parameters (1 with min/max=2/2)

Fortunately it’s easy to fix if you doing what you are doing.

First you have to create a new project in GNS3, just click and drag a single router and boot it. Configure a hostname or a loopback or something and type write memory in the console. Now go to GNS3 and click on file and save project as, don’t forget to click on the save IOS startup configurations. Close GNS3 and open your topology .NET file in wordpad. it will look pretty much the same as my example:

autostart = False
    workingdir = C:\DOCUME~1\VMWare\LOCALS~1\Temp
    udp = 10000
        image = C:\Documents and Settings\VMWare\Desktop\C3640-JK.BIN
        ghostios = True
        chassis = 3640
    [[ROUTER R1]]
        model = 3640
        console = 2003
        cnfg = configs\R1.cfg
        x = -100.0
        y = -56.0
    configs = configs

Now open up my topology file in wordpad, as an example I took the EIGRP Beginner lab i created sometime ago. It’s not the entire file just a part of it:

autostart = False
    workingdir = /tmp
    udp = 10000
        image = /Data/IOS Images/c3640-jk9s-mz.124-16.bin
        idlepc = 0x6059c528
        ghostios = True
        chassis = 3640
    [[ROUTER R1]]
        model = 3640
        console = 2001
        slot0 = NM-1FE-TX
        f0/0 = R2 f0/0
        slot1 = NM-1FE-TX
        f1/0 = R3 f0/0
        x = -355.0
        y = -225.0
    configs = EIGRP Beginner_configs
    m11 = 1.41421356237
    m22 = 1.41421356237
    [[NOTE 1]]
        text = Y
        x = -479.418397644
        y = 7.79898987322
        color = "#1a1a1a"

Do you see the difference? The localhost might be different, it’s probably in your topology file. The workingdir is different for sure and so is the image location.

Let me compare them:

EIGRP Beginner: [localhost:7200]

New Project: []

EIGRP Beginner: workingdir = /tmp

New Project: workingdir = C:\DOCUME~1\VMWare\LOCALS~1\Temp

EIGRP Beginner: image = /Data/IOS Images/c3640-jk9s-mz.124-16.bin

New Project: image = C:\Documents and Settings\VMWare\Desktop\C3640-JK.BIN

And you might have to check the configs directory structure. I’m also probably using another idlepc value so it’s good to copy yours in the topology file.

So how to fix it? Easy! Just copy and paste your information in my topology file and save it. Open it in GNS3 and voila…….a working lab!

If you want a real life example just watch this video I created:

If you have any questions or think this is useful please let me know by leaving a comment.

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René - CCIE #41726 is the creator of GNS3Vault.com where he shares CCNA, CCNP and CCIE R&S labs. He also blogs about networking on http://networklessons.com


  1. It works, Great!.

    Only issue is the hostname is not replace, we see 2 hostname’s in topology

  2. hi all
    can someone help please? I am trying to open the lab sim but keep getting this error mssg in gns3 ?
    I have downloaded the right ios image.


    1. Hi Cysag,

      Did you get this resolved? 90% of the GNS3 errors are related to filenames, foldernames and/or IOS images.

      Can you run your own topologies? Did you try editing the .NET topology file to see if it makes any difference?


  3. Rene:
    When using someone else’s .NET file here’s a little tip I use.
    Edit the "workingdir =" and don’t put a destination path. Just put "workingdir=working". Also, in the GNS3 Data section put "workingdir=working" and "configs=configs". Don’t put a path, . If there is a path in either line change it to "working" or "configs". When you do both of these and save to a Project directory GNS3 will create a directory with your Project name and two subdirectories:
    "working" and "configs". If you ever want to look at the working directory you know it always in the Project you named.

  4. Installed GNS3 successfully,Able to bring routers,possible to switch on routers. But for config console is hanging and not opening? suggest a solution,Pl.

  5. I dont know if this is the correct place to ask about GNS3. When I open GNS3 and add 2 or more routers (2600 series for example), CPU goes to 100% and the memory too!! GNS3 freeze and my laptop has a low response.

    Intel CPU (2 Core) U4100 (1.30 GHz)
    8 GB RAM
    64 bits
    500GB Hard Drive (190GB Free)
    Windows 7 Professional

    Do you have a suggestion for this issue? Some time is impossible work with GNS3

    Thanks in advance!

    1. You need to right-click the router and select Idle PC value …. GNS3 will search for a value and display it for you to choose. check that in the drop down menu there are values with * next to them – these are the best Idle PC values.
      Select a value and check your CPU – if the use drops to 2-6 % you have the right Idle PC value; if not, you have to keep searching for the right Idle PC value.

      Hope this helps

  6. I have downloaded he gns3, but IOS image is not there. Please let me know the process and send me the link for ios image. I have to practice some EIGRP and BGP lab.

  7. Hi Rene.

    I am a regauler user of GNS3VAULT… Yesturday I made some changes in laptop.. After that its giving bellow error… plz help.

    hypervisor manager massage :

    Can’t connect to the hypervsor on localhost port 7201: [ Err no 10061 ] No connection could be made because the target machine actively refused it…….

    Thanks in advance.

  8. Hi Rene,

    First of all thanx for ur lab scenarios. I want to connect virtual box in GNS3 with Windows XP iso. But when i run that iso it gives me error of " Fatal Error System can’t boot ". I also tried virtual box with ubuntu it works fine…but with this windows iso it gives mesuch error.So, whats the problem is there any iso issue…? So can u just give me that link to download that windows iso….or give some suggestion. Thanx in advance. God bless u.

  9. hi .when i downlod any lab nothing is been preconfigured.just got the topology and routers with the interfaces but the ip address not assighned ? !!

  10. when i issue reload command on router it fails to reboot even other command do not work so what can i do?

  11. Hey There. I found your blog using msn. This is a very well written article.
    I will make sure to bookmark it and come back to read
    more of your useful information. Thanks for the post.
    I will certainly comeback.

  12. 203-Bad number of parameters (1 with min/max=2/2)

    this problem comes because the folder of IOS may have some files with names too long…. I have arranged the problem so….my GNS3 works ok.

  13. Hi every one

    I really need help about my GNS3 I have just refreshed my windows 8 now my GNS 3 dosnt work properly and my router icons not active any more what shall i do please

    with many thanks

  14. Renee, (or anyone else?)

    Can someone tell me how to open the topology files? do you need version 1.0?

    I have a working version of 8.7 that I’ve used for awhile. I download various startup file links and “open with” the topology files directly with GNS3 and it only opens with a white desktop on GNS3, no routers nothing.

    When I tried the above procedure, even though I wasn’t getting that error per se…..the .NET files opened with Wordpad don’t look like the above. They don’t start with typical…

    autostart = False
    workingdir = C:\DOCUME~1\VMWare\LOCALS~1\Temp
    udp = 10000
    image = C:\Documents and Settings\VMWare\Desktop\C3640-JK.BIN
    ghostios = True
    chassis = 3640

    Instead they start like this:

    “name”: “OSPF Virtual Link”,
    “resources_type”: “local”,
    “topology”: {
    “ellipses”: [
    “border_style”: 2,
    “fill_color”: “#ffff7f”,
    “height”: 200.0,
    “width”: 357.79603128,
    “x”: -347.896536344,
    “y”: -149.19953083,
    “z”: -2.0
    “border_style”: 2,
    “fill_color”: “#aaff7f”,
    “height”: 126.572113832,
    “width”: 133.643181644,
    “x”: -311.834090503,
    “y”: -270.821897194,
    “z”: -2.0

    can someone tell me what I am supposed to do? Or do i just need to upgrade to 1.0 to get them to work?


    1. i am facing the same problem. When i unzip the startup config file it was showing .gns3 file istead of .net file..So how to open that file

      1. Hi Jay,

        I know you may have already figured it out by now, but the newer GNS3 looks to open .gns3 files by default. Rene, has gone through most of his labs and converted the files .gns3 files.

        For the ones that are still downloading as .net files, GNS3 can still open them. You just have to make sure that when you attempt to open a project, the file type you have selected is set to “all files *.*” By default, the file type will be set to “GNS3 project files”, which is why .net files won’t show at first.

        It’ll open the .net file and then immediately prompt you to allow it to recreate it and rename it into a .gns3 project.

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