LFNE GNS3 Appliances

This post will be a very short one, more like a note :)

Based on the LFNE Docker images (explained here https://ipnet.xyz/2023/11/lfne-linux-for-network-engineers) I’ve created the GNS3 Appliances for easy import into GNS3.

The GNS3 Appliances can be downloaded here https://github.com/yotis1982/lfne and imported into GNS3.

Have fun!

LFNE – Linux For Network Engineers

Formerly known as PFNE – Python For Network Engineer, the images developed to be more than just for Python learning. My choice was to call the new one more generic and pick the Linux For Network Engineers (LFNE)

Linux images build with all tools need by network engineers to perform various tasks ranging from simple python script to automation and testing.
Below is the list of installed applications on LFNE images. Pull one and start experimenting.

I’m using two main distributions to build these images – Ubuntu and AlmaLinux – pick your favorite flavor. I picked AlmaLinux as is the closest distribution to now (almost) defunct Centos.

LFNE based on Ubuntu 22.04

Pull the image:
docker pull yotis/lfne:ubuntu-22.04
Use the image:
docker run -i -t yotis/lfne:ubuntu-22.04 /bin/bash
If used with Portainer don’t forget to activate the option for Console : Interactive & TTY

LFNE based on AlmaLinux 9.2

Pull the image:
docker pull yotis/lfne:almalinux-9.2
Use the image:
docker run -i -t yotis/lfne:almalinux-9.2 /bin/bash
If used with Portainer don’t forget to activate the option for Console : Interactive & TTY

Some of the installed packages:

Net-tools (ifconfig…)
IPutils (ping, arping, traceroute…)
Host (DNS lookup tool)
Mtr (traceroute tool)
Telnet / SSH client
IPerf (traffic generator)
Python 2 (only on Ubuntu variant)
Python 3
Openssh Server

To use remote ssh connection to container

  • Enable it with “service ssh start”
  • Expose the desired port for the container (tcp/22 default)

MicroStack installation fails on Ubuntu 20.04

I needed an instance of Openstack in my home lab for some tests and the first attempt was to deploy it with DevStack all-in-one. Is one of the most common methods out there. However it kept on failing (still need to find out why), so I turned to MicroStack.

MicroStack describe itself as the most straightforward way to install Openstack. I don’t say this is the way to go for Enterprise grade installation, but would do if you want something simple like one or two nodes for testing, learning purposes.

MicroStack uses two commands to have an Openstack instance up and running:

sudo snap install microstack --beta
sudo microstack init --auto --control

You can read a more detailed “how-to” on the Ubuntu or MicroStack page. One note, the entire topic is in Beta stage.

I’ve tried deploying multiple time on fresh Ubuntu 20.04 installation and everytime I’ve ended up with the error below. I’m adding the entire text, just in case you encounter an error at certain installation stage and want to check if is the same like mine:

sudo microstack init --auto --control
2022-11-02 20:21:19,950 - microstack_init - INFO - Configuring clustering ...
2022-11-02 20:21:20,454 - microstack_init - INFO - Setting up as a control node.
2022-11-02 20:21:24,066 - microstack_init - INFO - Generating TLS Certificate and Key
2022-11-02 20:21:26,187 - microstack_init - INFO - Configuring networking ...
2022-11-02 20:21:42,675 - microstack_init - INFO - Opening horizon dashboard up to *
2022-11-02 20:21:43,807 - microstack_init - INFO - Waiting for RabbitMQ to start ...
Waiting for
2022-11-02 20:21:56,629 - microstack_init - INFO - RabbitMQ started!
2022-11-02 20:21:56,629 - microstack_init - INFO - Configuring RabbitMQ ...
2022-11-02 20:21:58,753 - microstack_init - INFO - RabbitMQ Configured!
2022-11-02 20:21:58,953 - microstack_init - INFO - Waiting for MySQL server to start ...
Waiting for
2022-11-02 20:23:08,775 - microstack_init - INFO - Mysql server started! Creating databases ...
2022-11-02 20:23:14,509 - microstack_init - INFO - Configuring Keystone Fernet Keys ...
2022-11-02 20:26:07,658 - microstack_init - INFO - Bootstrapping Keystone ...
2022-11-02 20:26:21,999 - microstack_init - INFO - Creating service project ...
2022-11-02 20:26:27,938 - microstack_init - INFO - Keystone configured!
2022-11-02 20:26:28,257 - microstack_init - INFO - Configuring the Placement service...
2022-11-02 20:26:49,572 - microstack_init - INFO - Running Placement DB migrations...
2022-11-02 20:27:09,282 - microstack_init - INFO - Configuring nova control plane services ...
2022-11-02 20:27:22,369 - microstack_init - INFO - Running Nova API DB migrations (this may take a lot of time)...
2022-11-02 20:29:02,089 - microstack_init - INFO - Running Nova DB migrations (this may take a lot of time)...
Waiting for
2022-11-02 20:39:31,994 - microstack_init - INFO - Creating default flavors...
2022-11-02 20:39:59,738 - microstack_init - INFO - Configuring nova compute hypervisor ...
2022-11-02 20:39:59,738 - microstack_init - INFO - Checking virtualization extensions presence on the host
2022-11-02 20:39:59,756 - microstack_init - WARNING - Unable to determine hardware virtualization support by CPU vendor id "GenuineIntel": assuming it is not supported.
2022-11-02 20:39:59,756 - microstack_init - WARNING - Hardware virtualization is not supported - software emulation will be used for Nova instances
2022-11-02 20:40:06,690 - microstack_init - INFO - Configuring the Spice HTML5 console service...
2022-11-02 20:40:08,564 - microstack_init - INFO - Configuring Neutron
Waiting for
Traceback (most recent call last):
  File "/snap/microstack/245/bin/microstack", line 11, in <module>
    load_entry_point('microstack==0.0.1', 'console_scripts', 'microstack')()
  File "/snap/microstack/245/lib/python3.8/site-packages/microstack/main.py", line 44, in main
  File "/snap/microstack/245/lib/python3.8/site-packages/init/main.py", line 60, in wrapper
    return func(*args, **kwargs)
  File "/snap/microstack/245/lib/python3.8/site-packages/init/main.py", line 228, in init
  File "/snap/microstack/245/lib/python3.8/site-packages/init/questions/question.py", line 210, in ask
  File "/snap/microstack/245/lib/python3.8/site-packages/init/questions/__init__.py", line 887, in yes
    check('openstack', 'network', 'create', 'test')
  File "/snap/microstack/245/lib/python3.8/site-packages/init/shell.py", line 69, in check
    raise subprocess.CalledProcessError(proc.returncode, " ".join(args))
subprocess.CalledProcessError: Command 'openstack network create test' returned non-zero exit status 1.

I’ve did some research and I found some hints about the need to manually install Python on a fresh Ubuntu 20.04 instance:

sudo apt install python python-dev

After installing Python all worked like a charm:

sudo microstack init --auto --control
# Skipped text #
2022-11-02 21:18:18,159 - microstack_init - INFO - Configuring the Spice HTML5 console service...
2022-11-02 21:18:19,503 - microstack_init - INFO - Configuring Neutron
Waiting for
2022-11-02 21:19:21,615 - microstack_init - INFO - Configuring Glance ...
Waiting for
2022-11-02 21:20:53,119 - microstack_init - INFO - Adding cirros image ...
2022-11-02 21:20:57,002 - microstack_init - INFO - Creating security group rules ...
2022-11-02 21:21:09,046 - microstack_init - INFO - Configuring the Cinder services...
2022-11-02 21:22:10,868 - microstack_init - INFO - Running Cinder DB migrations...
2022-11-02 21:23:31,155 - microstack_init - INFO - restarting libvirt and virtlogd ...
2022-11-02 21:23:42,260 - microstack_init - INFO - Complete. Marked microstack as initialized!

For some reason the MicroStack initialization process doesn’t detect Python installation or more like it the lack of.

If you have this error during installation, let me know if manual Python installation does the job.

Ubuntu 20.04 Docker image – Python For Network Engineers

This is an updated Docker image of Python For Network Engineers (PFNE) based on Ubuntu 20.04 (minimal server distro).

It contains all necessary tools for network / devops engineers to test automation and learn Python:

Python 2
Python 3

If you notice a missing package which could be a value added for the scope of the Ubuntu PFNE image, please let me know in comments below.

Before testing the new Ubuntu 20.04 PFNE Docker image, please pull it from Docker Hub:

docker pull yotis/ubuntu2004-pfne

To start using it:

docker run -i -t yotis/ubuntu2004-pfne /bin/bash

For more details about how to install, operate and create your own Docker images, please check my older article on How to create your own Docker image.

ESXi VM – The CPU has been disabled by the guest operating system

For some weeks now, a couple of my virtual machines on ESXi would stop working out of nowhere. They were completely unresponsive (including via the ESXi VM Console). Nothing would help, except a shutdown / start of the VM. Just to find out later that, randomly, the VM would become unresponsive again.

The only human readable information about these failures was in the ESXi host Events and was saying something like this (among other things):

 The CPU has been disabled by the guest operating system

One other thing which I should mention is that all my VM encountering this issue where Linux based, mainly Ubuntu 20.04 as OS distribution.

Not much to work with, but I gave it a try and searching for the error did point me to this VMware KB: https://kb.vmware.com/s/article/2000542

The KB is clearly accurate, just that it didn’t help me at all to resolve my problem. The troubleshooting process explain in the KB lead me to a dead end.

Other web resources (for the above error) pointed to articles which explained a procedure for VMware Workstation / Player. Not my case, since I’m using ESXi.

More research done, which took a while – that’s why I’m writing this article, hopefully others with this problem will find it easier – pointed to a BUG. Seems this BUG is a particular case between my VM Linux kernel and the version of the ESXi I’m using currently.

I’ve arrived to this VMware KB https://kb.vmware.com/s/article/2151480 which was a game changer. In my case this KB was hard to find, because the title – Linux VM fails with the error “kernel BUG at drivers/net/vmxnet3/vmxnet3_drv.c:1413!” (2151480) – is completely different than the error I was seeing and which I used searching the web.

Skipping the long output at the beginning of the KB, I saw something interesting in lower part of the page:

This issue occurs due to a bug in VMXNET3 vNIC backend which is part of the vmkernel. This issue occurs if the following conditions are met:

    Linux VM is running kernel >= 4.8
    HW version of VM is >=13
    ESXi version is 6.5

All the above fits my scenario, VMXNET3 as vNIC, Kernel 5.4, VM HW version 13 and ESXi 6.5

Like in most of BUG cases, the obvious solution is upgrade. Same here:

This issue is resolved in VMware ESXi 6.5 U1

Just that I cannot upgrade now for various reasons.

So, I’ve decide to look into the workarounds.

Second workaround on the page seems to be more simple and I don’t even have to restart the VM:

ethtool -G ethX rx-mini 0

Of course replace the ethX with your interface name.

Worked like a charm without any visible side-effects.

The other workaround is also doable, but I didn’t want to modify the .vmx file

Power off the virtual machine
Edit the vmx file and add the below parameter:
vmxnet3.rev.30 = FALSE
Power on the virtual machine

Now I’m just curious if I would encounter the same issues using another vNIC adapter type, like E1000 or E1000E instead of VMXNET3. Maybe I’ll give it a try…