Mininet: iperf fails + can't add flows in user-space switch

Question

I am new to mininet and SDN. Following is an issue I came across while exploring iperf command.

1) Set up a topology with three hosts and a user-space switch with following command:

$ sudo mn --topo single,3 --mac --controller remote --switch user

2) No flow routes have been added.

3) Run a reference controller (POX) with following command:

$ controller ptcp:

4) iperf testing with following command:

mininet> iperf (on mininet console)

Error #1: iperf testing fails because flow routes are not defined. This is followed by a complete cleanup.

5) To fix this, I tried to add flow route with following command:

$ ovs-ofctl add-flow s1 in_port=1,actions=output:2

Error #2: I get following error message:

ovs-ofctl: s1 is not a bridge or a socket

Can anyone tell me what is my mistake? How can I fix this?

Reference: https://github.com/mininet/openflow-tutorial/wiki/Learn-Development-Tools

Answer 1

Try this: controller ptcp:6633

If that doesn't work let me know what the output is.

I fell good about that controller command. Go to pox directory and try this:

./pox.py forwarding.tutorial_l2_hub

I assumed that you have pox already installed if you dont follow either of the instructions here:

1. This uses presetup VM: http://sdnhub.org/tutorials/pox/

2. Directly cloning it:

   $ git clone http://github.com/noxrepo/pox
   $ cd pox

I hope it helps. Let me know if you need more help.

Some usefull resources: https://openflow.stanford.edu/display/ONL/POX+Wiki#POXWiki-InstallingPOX

Answer 2

Also remember that based on user account privilege you may need to use sudo before the command. So if something doesn't work try it with sudo as well.

Have a look at following output. let me know what part is different.

ubuntu@sdnhubvm:~/pox[14:38] (eel)$ ls 
debug-pox.py@  LICENSE  pox/     README     tests/
ext/           NOTICE   pox.py*  setup.cfg  tools/
ubuntu@sdnhubvm:~/pox[14:38] (eel)$ pwd
/home/ubuntu/pox
ubuntu@sdnhubvm:~/pox[14:38] (eel)$ git remote -v
origin  http://github.com/noxrepo/pox (fetch)
origin  http://github.com/noxrepo/pox (push)
ubuntu@sdnhubvm:~/pox[14:38] (eel)$ ./pox.py forwarding.tutorial_l2_hub
POX 0.5.0 (eel) / Copyright 2011-2014 James McCauley, et al.
INFO:core:POX 0.5.0 (eel) is up.

Answer 3

Use xterm h1 then call iperf -s or iprf -c.

Answer 4

Running iperf by itself in the topology in the tutorial attempts to run the test between h1 and h3. You need to create the flow entries between those two hosts:

dpctl add-flow tcp:127.0.0.1:6634 in_port=3,idle_timeout=120,actions=output:1

dpctl add-flow tcp:127.0.0.1:6634 in_port=1,idle_timeout=120,actions=output:3

Change the timeouts from 120 to something higher if you want. iperf should run just fine after this.

Answer 5

I also got

ovs-ofctl: s1 is not a bridge or a socket

It disappeared when I executed

mininet@mininet-vm:~$ export XAUTHORITY=~/.Xauthority