August 8, 2020

How To Configure Access Router In GNS3 LAB

When you are working in a Cisco Lab environment you cant keep on changing the console cable from one router to another for configuration for this purpose an access server is used.  Access server has several config cables coming out from a single port. These cables can be connected to different routers in the network. Now while only logging into a single router we can configure all the other routers that are connected using the special cable.

Now this is the case with real routers, when you are using GNS3 as simulator then it also becomes a hassle to manage the console of each router.  Tools like puttycm and secureCRT can be used but still these have multiple consoles.

There is one cool way to use a router as an ACCESS server in GNS3

Now to configure ACCESS router in GNS3 follow the steps :-


Step1.) This requires the installation of a microsoft loopback adapter. Access server will use this adapter as a mean to connect the other routers.

Step2.) To add a microsoft loopback adapter open device manager. In windows 7 you can right click the my computer icon -> click properties then a window appears now click on device manager.

Step3.) Now in device manager goto ACTION tab and click on add legacy hardware. A screen like this will appear.

How To Configure Access Router In GNS3 LAB

Now click on NEXT.

Step4.) Now select . Install the hardware manually from list.

How To Configure Access Router In GNS3 LAB

Step5.) Select Network Adapters from the list.

How To Configure Access Router In GNS3 LAB

Step6.) Select the Microsoft from the Manufacturer’s list and loopback adapter from the network adapters list.

How To Configure Access Router In GNS3 LAB

Step7.) Now after finishing the install Reboot the computer. For loopback adapter to work correctly it is necessary to reboot.


Step1.) Now open GNS 3 and drag a cloud. Right click the cloud and click on NIO ethernet tab.

How To Configure Access Router In GNS3 LAB

Step2.) Now select the microsoft loopback adapter from the list of ethernet cards and click on add. Now connect the router to cloud using a fastethernet connection.

Step3.) Now add the routers to the scenario to which you want the access server to connect. I am adding two routers R2 and R3.

Now the scenario should look something like this.

How To Configure Access Router In GNS3 LAB

Step4.) Right click the routers R2 and R3 and click on change console port. You will get the screens like this. Note down the port numbers. These port numbers will be used by access server in gns3 to connect to router R2 and R3 using router R1 which is access server.

How To Configure Access server Router In GNS3 LAB

Step5.) Now start the Router R1 and login to global configuration mode.

R1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#int fast
R1(config)#int fastEthernet 0/0
R1(config-if)#ip address
R1(config-if)#no shut

Step6.) Now navigate to control panel-> Network and sharing centre-> change adapter setting. Select the microsoft loopback adapter and right click. Click on properties and select the IPv4 again click on properties. Now enter the following ip address information.

How To Configure Access server Router In GNS3 LAB

Step7.) Now switch on router R3 and R2 and goto console of R1 and enter the following commands.

Note:- After entering the Ip information in the loopback interface just try pinging the ip address of loopback from the Router.

R1(config)#ip host R2 2001

R1(config)#ip host R3 2002

The command syntax is ip host <hostname> <telnet port> < ip address>

in our cases the host names are R1 and R2 , Telnet port are 2001 and 2002 ( Checked using step 4 of part2.) and ip address is of the loopback adapter.

Final Step.) Now to goto the R2 or R3 from the console of R1 exit the global conf mode and just type R2 or R3 and its done.

You have just configure access server on GNS3 🙂 if you have any problems setting this access server in your gn3 leave a reply.

Akash Deep Singh

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45 thoughts on “How To Configure Access Router In GNS3 LAB

    1. Hi praveen you can connect gns from one system to another system. I will come up with an article soon may be tonight if I get time.

  1. Hi i am in need of help, i am preparing for my ccna, ccnp, ccsp, ccie security, can you please let me know what are the equipments needed to pass ccna, ccnp, ccsp, ccie-security, even if i am not able to buy it alteast i could join a institute where they have all these equipments. There are many institutes, have to find the right one kindly help. Looking forward for your reply.

    Thank you

    1. Hi jeshel sorry for late reply,,

      You have long list of certifications lined up. Conquer them one by one its good than you have a goal. I dont know you belong to which country, If you belong to asian continent buying hardware for practice is quite expensive. If you live in north america then you can buy some cheap hardware for practice,\

      In both cases if you dont want to spend money you can use GNS3.You cant use GNS3 for switching ( only for routing ) you can find the gns3 article here

      Now about institutes, you can join them but only few Institutes have hardware equipments rest provide you with simulators.

      My choice is to use GNS3 for your ccna when you clear your ccna then you can decide whether you can go for h/w equipment or not. I read Todd Lammle’s ccna study guide ( Sybex) which I think is the best guide for CCNA start with it and let me know if you need any further help.

  2. hi dear
    i did all that you said. but, i keep getting this message:

    Translating “r2”
    Trying r2 (, 2001)…
    % Connection refused by remote host

    thanx in advance

    1. Hey ramzi. Strange try enabling telnet in the routers. Ping from console router to windows loopback and from windows command line try pinging the console router’s I.P.

  3. i am able to ping from both sides from windows to router interface
    but i am unable to reach to other routers in the topology

  4. Hi,
    My name is Dave, and i am using GNS vbox edition in core 2 duo with 2 gig Ram,
    After configuring the access server , i have lost connection to R1 and error i have recevied is lost communication to dynamips server.
    Please guide me, how to sort this out.

  5. Hi,

    I am also facing same error while accessing R2 and R3 routers.

    Translating “r2″
    Trying r2 (, 2001)…
    % Connection refused by remote host

        1. Loopback Adapter is pain in MAC. I will find a way if possible. I am contacting my friend who has a mac. I had to sell my mac just to buy a new lab for my VMWARE environment.

  6. Translating “r2″
    Trying r2 (, 2001)…
    % Connection refused by remote host

    I have done all of the above configuration.. I can ping from Accserver to my loopback and vice-versa..
    The problem is I cant connect to neither R2 or R3.. I tried many solutions for 2 3 days but still its the same problem.. I used 2600 2690 3600 3700 7200, and still the same problem. Used with putty and securecrt.. I have windows 7 64bit and have the latest gns3n 0.8.6

    1. If you are getting a message which says CONNECTION REFUSED then it means your request is reaching the remote router but not being handled. Looks like you havent enabled TELNET on those routers.

  7. I dont see that you have enabled anything on the R2 and R3.. although i did try to enable telnet on them still its saying the same thing..

  8. Please i am encountering the same issue, configuration is well done, but i still get “connection refused by remote host” i am using GNS3 0.8.6 under Windows 7 64bit.

    1. The only thing that I can think of right now is the issue with telnet. Connection refused means the service is not active. Just check whether the telnet is active on your router images.

  9. Thank you for your prompt response.
    It seem to be working when i change GNS3 version, from 0.8.6 to 0.7.3, without any config change .
    The issue seem to be concerning 0.8.6 ver on win 7

    1. Oh sorry My mistake. In access router there should be no concept of telnet as we are going through loopback in GNS3. I have to dig around this issue with the version you mentioned.

      My advise for right now is to go back the version where it worked for you.

  10. Hi Akash,
    I am also having the same problem as you people are talking about. I am also using gns3 0.8.6 on windows 7. Every steps/tests(like ping test form router to loopback and reverse) went well as you have mentioned in this document.

    1. Hello Grish,

      I guess then you have to downgrade the version of your GNS3. This post is quite old and I dont have the setup to try it again.

      1. Thank you Akash for your response. I also have tested it with lower version of gns3 v0.8.4 on ubuntu 14.04 but still getting the same problem. have you tried it on ubuntu before? if yes plz help me out. i am lingering with this problem since 4-5 days.

  11. hey Akash,
    i have installed lower version of gns3 v0.7.3 on windows7 and it working fine.
    thaks alot for your help dude!!

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