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Openstack dashboard release IP for project/tenant

This took me couple of hours to figure it out in UI. Hence documenting:

To release floating IPs from a tenant or project of openstack.

  1. Login to dashboard
  2. Compute –> Access & Security –> Floating IPs
  3. You should can sort by Status (‘Down’)
  4. Select the ones with pt 3 and click on ‘Release Floating IPs’ button
  5. You should see that these floating IPs are released for other tenants to pickup.
Categories: General


The opensource project I’ve been actively working on. I took a video today on this.



Categories: General

Connecting two Open vSwitches to create a L2 connection between sites

Remi Bergsma's blog

Recently I played with Open vSwitch and it’s awesome! Open vSwitch is a multilayer virtual switch and it brings a lot of flexibility in the way you can create interfaces and bridges in Linux. It’s also a Linux distribution independent way to configure these things. Switching in software!

To create a bridge, simply run:

You can also create another bridge on top of it, to handle a VLAN for example:

Even better, create a bond based on LACP:

This is all quite nice but still basic. It gets interesting when you realise you can connect two switches like you can put a patch cable between physical switches. To test how cross platform this works, I setup two boxes: a CentOS 7 box and a Ubuntu 15.04 one. This shows it in a picture:


We’ll create a new bridge and add a vxlan interface that connects to the other vswitch. Then create a…

View original post 871 more words

Categories: General

The need for Network Overlays – part II

The Network Way - Nir Yechiel's blog

In the previous post, I covered some of the basic concepts behind network overlays, primarily highlighting the need to move into a more robust, L3 based, network environments. In this post I would like to cover network overlays in more detail, going over the different encapsulation options and highlighting some of the key points to consider when deploying an overlay-based solution.

Underlying fabric considerations

While network overlays give you the impression that networks are suddenly all virtualized, we still need to consider the physical underlying network. No matter what overlay solution you might pick, it’s still going to be the job of the underlying transport network to switch or route the traffic from source to destination (and vice versa).

Like any other network design, there are several options to choose from when building the underlying network. Before picking up a solution, it’s important to analyze the requirements – namely…

View original post 1,684 more words

Categories: General

Adding ssh-keygen manually

February 23, 2017 Leave a comment

test@testenv:/# ssh-keygen -t rsa -b 4096 -C "karun.chennuri@test.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
90:b9:6d:84:9e:bc:71:80:19:12:ec:e4:5d:51:11:dc karun.chennuri@test.com
The key's randomart image is:
+--[ RSA 4096]----+
| .o.. .+++ |
| o. +.+. E |
| + .o.* . |
| o .o B |
| * S |
| = |
| . |
| |
| |

test@test-env:~$ ssh-add
Could not open a connection to your authentication agent.

# If you see above error then
$ eval 'ssh-agent -s'
SSH_AUTH_SOCK=/tmp/ssh-pxa9H7geUdOJ/agent.31326; export SSH_AUTH_SOCK;
echo Agent pid 31327;

$ SSH_AUTH_SOCK=/tmp/ssh-pxa9H7geUdOJ/agent.31326; export SSH_AUTH_SOCK;
$ SSH_AGENT_PID=31327; export SSH_AGENT_PID;

# Then again issue below command ssh-add this time it should work...

test@testenv:/# ssh-add -l
The agent has no identities.
test@testenv:/# ssh-add
Enter passphrase for /root/.ssh/id_rsa:
Identity added: /root/.ssh/id_rsa (/root/.ssh/id_rsa)
test@testenv:/# ssh-add -l
4096 90:b9:6d:84:9e:bc:71:80:19:12:ec:e4:5d:51:11:dc /root/.ssh/id_rsa (RSA)

Categories: General

VNCServer setup (Ubuntu desktop)

February 14, 2017 Leave a comment

Steps to Install VNCServer on any VM

ubuntu@karun-sec-4:~$ apt-get update
ubuntu@karun-sec-4:~$ apt-get install -y gnome-core xfce4 xfce4-goodies vnc4server tightvncserver

# If the folder .vnc not found, go ahead and create it manually & also xstartup file
ubuntu@karun-sec-4:~$ vi ~/.vnc/xstartup


gnome-panel &
gnome-settings-daemon &
metacity &
nautilus &
gnome-terminal &
startxfce4 &

# If the folder .config not found, go ahead and create it manually
ubuntu@karun-sec-4:~$ sudo chown -R ubuntu:ubuntu ~/.config

#If gray screen
sudo chown ubuntu:ubuntu ~/.vnc/xstartup
chmod 755 ~/.vnc/xstartup

ubuntu@karun-sec-4:~$ vncserver -geometry 1920x1080 -depth 24 :1

# TightVNC client open and
<ip address>::5901

password: <password>

Now click on connect button

#Note: to kill VNCserver
ubuntu@karun-sec-4:~$ vncserver -kill :1

Categories: General

Steps to create a new Interface on Ubuntu 14.04 VM of Openstack

February 9, 2017 Leave a comment

In your ubuntu VM execute steps 1 and 2 below
1. Add new /etc/network/interfaces.d/eth1.cfg
auto eth1
iface eth1 inet dhcp

2. sudo /etc/init.d/networking restart
Login to openstack dashboard now
3. On your instance select “Attach Interface” (In the popup chose a new network interface that you may’ve configured already)

4. Restart VM now, you should see your eth1 pick up an internal IP from the network.
Categories: General