The following will be applicable for Microsoft Windows.

To configure a Terminal Server for a Lab in GNS3, I am just discussing the topic only, not how to install GNS and get the IOS images for the routers you use in this lab.

Install Microsoft Loopback Adaptor, and assign an IP address to it. I am using 192.168.10.1 in my example.

Open your GNS3, as an administrator, and create a cloud. Select your Microsoft Loopback Network Adaptor from drop down list as the Generic Ethernet NIO and Add it.

Now add a router in GNS3 that will act as your Terminal Server. After necessary (fast)ethernet port configuration, connect this router to the cloud. Configure an IP address in the Router interface and ping the host. You can try to ping from the host as well. For me the Router interface IP address is 192.168.10.2.

Now enable telnet or ssh on your router and configure the hosts that you want to access from this Terminal Server, as follows:

ip host R2 2002 192.168.10.1
ip host R3 2003 192.168.10.1

You may need more. Configure each host like this. Further, to avoid any mismatched host take much time to resolve, you may consider this:

no ip domain lookup

That’s it! No, at least not yet. You have to confirm if the ports you defined for your hosts match. For this, right click on each of the routers and click on Change console port and verify.

Once you’ve done, you are now ready to telnet to your Terminal Server from your host.