ping issue in Mininet custom topology

Question

I have build custom network topology in mininet 105 switches connected with each other by speficied logic, and every switch has a node connected with that.

the problem is when i ping s2 --> s94 packet reaches to the destination but when i invoke ping from h2 --> h94 it shows total packet loss.

can anyone guide me why is that? its important since i have to generate traffic over network.
i am using Mininet Vm http://mininet.org/download/

Answer 1

For Mininet 2.0.0, the default controller for the mn command is ovs-controller (which can be installed automatically in Ubuntu.) Unfortunately ovs-controller only supports up to 16 switches. If you want to use more than 16 switches, you should use a controller that supports more than 16 switches .

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Solution: Try POX controller!

GITHUB download link

Documentation

Answer 2

Use a pox controller. In the controller terminal,

$cd pox $./pox.py openflow.discovery forwarding.l2_learning

Now try a pingall

Answer 3

If the topology contains loops I'm not sure if pox will do the job. Previously had a similar issue when I basically needed STP or similar. The Onos controller can do this for you.

What could be mentioned here is that switches in mininet are running in the host net namespace (as apposed to hosts that are running in their own namespaces). So pinging from s2 is likely to give you weird results anyway. If you for example would do s2 ifconfig you would see all interfaces of all switches. My point is, testing connectivity by using the switches can be misleading.

Also, as the other posts tell you, you obviously need a OF controller.