Hi,

I followed up Openflow-tutorial and installed Ubuntu-desktop with using this prompts:
$ sudo apt-get update
$ sudo apt-get install xinit ubuntu-desktop virtualbox-guest-dkms
(restart vm - I am using virtualbox)
$ startx

But only what I got, was empty background. So I found on ubuntusk.com this prompt:
rm ~/.gconf ~/.gconfd ~/.metacity ~/.compiz-1 ~/.config/compiz-1 ~/.config/dconf -rf

After that my launcher showed. But after restart VM it was hidden again.

So I would ask how I can fix this?

And is it possible set this VM for running GUI after start or restart VM? Now I start VM and see terminal and after typing credentials (mininet/mininet) I have to type startx for GUI.

I'm not exactly Linux-person but I try learning SDN technology for my diploma.

Thank you for your help!

Klaris

So I am following the instructions here https://github.com/mininet/openflow-tutorial/wiki/Learn-Development-Tools

I am at the part where I need to start WireShark.

I ran the command to start it, it does start, but scrolling does not work. By scrolling, I mean using the scroll on part of wireshark window that has scrollbar.

I managed to use keyboard to select l0 and press start as instructed, but also nothing seem to happen.

Any idea what to do?

I am running on:

Host Os: Ubuntu 18.04.3 LTS
VirtualBox 5

I was going through the OpenFlow tutorial today and had difficulties with the section Start Controller and view Startup messages in Wireshark.

The command controller in $sudo controller ptcp:6633 could not be found. For me, the correct command is ovs-testcontroller, but this depends on the distro according to this comment.

Furthermore, it might be worth mentioning that the controller process runs in the foreground after executing the command. I was waiting for some message to appear and it took me some time to realize that the controller was already in ready state.

It would be great if you could adjust the tutorial accordingly.

How can we generate enough traffic to stress mininet switch for benchmark testing

In chapter Router Exercise, it seems that the image that shows the basic topology is trasparent something that causes the following problem when GitHub's dark theme is enabled:

Greetings,

I've installed Mininet-VM. I was advised to add an additional host-only network adapter so I can use log in to the VM image. But this is what I get when I try to add the host-only adapter

Any help would be appreciated,

thanks,
Maryah

Page: https://github.com/mininet/openflow-tutorial/wiki/Set-up-Virtual-Machine

It says: C:> putty.exe -X openflow@[Guest IP Here]

It should say C:> putty.exe -X [user]@[Guest IP Here]

as the user may be mininet

Following the wiki and forgive me if this is the wrong location,
using the mininet vm on a host-only network
in mininet/openflow-tutorial/wiki/Learn-Development-Tools#benchmark-controller-wiperf
at the location
"
Start the same Mininet with the user-space switch:

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

Run one more iperf test with the reference controller:

mininet> iperf
"
when running iperf in a mn session with --controller remote --switch user having already set up controller ptcp: mininet crashes with the following output

mininet> iperf
*** Iperf: testing TCP bandwidth between h1 and h3 
no route to 10.0.0.3:
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.0.0.0        *               255.0.0.0       U     0      0        0 h1-eth0
--------------------------------------------------------------------------------
Caught exception. Cleaning up...

Exception: Could not connect to iperf on port 5001
--------------------------------------------------------------------------------
*** Removing excess controllers/ofprotocols/ofdatapaths/pings/noxes
killall controller ofprotocol ofdatapath ping nox_core lt-nox_core ovs-openflowd ovs-controller udpbwtest mnexec ivs 2> /dev/null
killall -9 controller ofprotocol ofdatapath ping nox_core lt-nox_core ovs-openflowd ovs-controller udpbwtest mnexec ivs 2> /dev/null
pkill -9 -f "sudo mnexec"
*** Removing junk from /tmp
rm -f /tmp/vconn* /tmp/vlogs* /tmp/*.out /tmp/*.log
*** Removing old X11 tunnels
*** Removing excess kernel datapaths
ps ax | egrep -o 'dp[0-9]+' | sed 's/dp/nl:/'
***  Removing OVS datapaths
ovs-vsctl --timeout=1 list-br
ovs-vsctl --timeout=1 list-br
*** Removing all links of the pattern foo-ethX
ip link show | egrep -o '([-_.[:alnum:]]+-eth[[:digit:]]+)'
( ip link del s1-eth1;ip link del s1-eth2;ip link del s1-eth3 ) 2> /dev/null
ip link show
*** Killing stale mininet node processes
pkill -9 -f mininet:
*** Shutting down stale tunnels
pkill -9 -f Tunnel=Ethernet
pkill -9 -f .ssh/mn
rm -f ~/.ssh/mn/*
*** Cleanup complete.

Hi. This might be a very basic issue, but I have been trying to configure a host-only network interface without success. I added host-only interface to VM and I can see it in mininet, but then when I execute sudo dhclient eth1, it kind of freeze and the command line disappears. When I use ifconfig-a, I don't see IP address with eth1, but I do see one in the settings.

Any help is appreciated!

Is it possible to dynamically adjust the rate at which packets are sent in python?

In the page Learn Development Tools, the flow generally goes like this:

• Start up Mininet for use with a remote controller.
• Do some experiments and learn how it works without a controller.
• Start Wireshark.
• Start the remote controller.
• Look in Wireshark for OpenFow messages exchanged by the controller and the switch.

This doesn't work, because the switch must reach out to the controller, and it can't do this if the controller is started later.

To make this work, you must:

• Shut down Mininet.
• Start the controller.
• Start Mininet again.
• Observe in Wireshark that the controller and the switch are communicating.

The goal of this issue is to accomplish one of the following:

1. Get the section "Start Controller and view Startup messages in Wireshark" changed to include the instructions shown immediately above.
2. Get an explanation of why my understanding is incorrect (which it very well may be).

Create a Learning Switch

The switch should give more bandwidth than a hub, but when I run Iperf after creating a controller based Ethernet switch, I get bandwidth at par with a hub.

Whereas a Flow-accelerated learning switch gives bandwidth in Gbits and is justifiable.

Or is it justifiable by the fact that, since for controller based ethernet switch, we are not installing any flows for the switch and as a result each incoming packet switch receives is sent to the controller, thereby resulting in lower bandwidth?

Can someone justify?

which version of open vswitch supports open flow 1.3 and 1.4 version

we use linear topology using this command.
sudo mn --topo linear,3 --switch ovsk --controller remote -x --mac
Why OpenFlow send multicast packet-in message (using this address 33:33:00:00:00:00:fb) continuously.

i created 3-tiers architecture used in datacenters in Mininet using learning switches without any controller, i added hosts at the access layer and tried to ping 2 hosts ( i tried it once with hosts connected to different switches in the access layer and i tried it with 2 hosts connected to the same access layer switch ) and the ping didn't work in both cases. i'm kinda new to networking so please help me understand WHY the ping didn't work ? and if the problem is because there is no routing protocols in the switches, please help me know how to configure learning switches without using controllers (because all the documentation found in the internet is about configuring switches in an SDN environement ).
Thanks.