networking - Fully open source network simulators?

06
2014-04
  • Gergely Buday

    I would like to teach networking using a network simulator. I learned of GNS3 but that requires commercial ios binaries.

    Is there a fully open source simulator with a graphical interface that allows the user to define a network topology and run routing experiments? Fully as in requiring no commercial software and preferrably including all the necessary ingredients.

    • Answers
  • chris

    You can use Cisco packet tracer, it is fully equipped with networking devices and configuration.


    • Related Question

    networking - How to route traffic to website using a specified network connection on Windows 7?
  • rwetzeler

    I want to route all traffic to a website over my wireless connection while the rest of the traffic using my lan. What I tried was first finding out the IP address of the website I want to go to. For example, lets say pandora.com. I found it resolves to 208.85.40.20. I have entered that entry into my hosts file. I then added that route using route add 208.85.40.20 mask 255.255.255.255 WirelessIP. It doesn't seem to work however. Instead of using the IP address, is there a way that I can just say.. this URL to route over that connection? Does anyone know of a program that I can install that will do this.. possibly some sort of proxy or a software load balancer that can do this?


    • Related Answers
  • rwetzeler

    Actually.. what worked for me is:

    route add qq.rr.ss.tt mask 255.255.255.255 WIRELESS_GATEWAY metric 1

    Specifying the interface may have worked.. but it worked for me the way I specified above so no need to specify interface condition

  • Seth

    Your route add command should work. But, you'll probably need to specify the interface and metric options: 

    route add qq.rr.ss.tt mask 255.255.255.255 metric 1 if uu.vv.ww.xx
                                   a low metric --^    ^-- your wireless ip

    If you don't specify the metric and the interface, Windows will figure out those values in such a way as to use your LAN connection.

    Windows will use the route with the lowest metric value. Metric is assigned based on relative speed. The LAN will always have a lower metric because it's a "faster" connection (100 Mbps or 1000 Mbps) than the wireless (54 Mbps).