Cumulus Linux Demo Framework

See the Layer 3 IP addressing

Virtualizing a Network with Cumulus VX

Cumulus VX is a virtual machine produced by Cumulus Networks to simulate the user experience of configuring a switch using the Cumulus Linux network operating system. Vagrant is an open source tool for quickly deploying large topologies of virtual machines. Vagrant and Cumulus VX can be used together to build virtual simulations of production networks to validate configurations, develop automation code, and simulate failure scenarios.

Vagrant topologies are described in a Vagrantfile, which is a Ruby program that tells Vagrant which devices to create and how to configure their networks. vagrant up will execute the Vagrantfile and create the reference topology using Virtualbox. It will also use Ansible to configure the out-of-band management network.

Using the Framework

The Cumulus Linux Demo Framework is built upon a Vagrantfile which builds the Reference Topology (pictured above). Using this topology, it is possible to demonstrate any feature in Cumulus Linux. It may not be necessary to use all links or all devices but they're present if needed by a particular demo.

This framework of demos is built on a two-tier spine-leaf CLOS network with a dedicated out-of-band management network. The topology built in this demo is the reference topology used for all Cumulus Networks documentation, demos, and course materials, so many demos will require you to build a topology using the code available in this repository.

Understanding What Is Provided

The following tasks are completed to make using the topology more convenient.

• DHCP, DNS, and Apache are installed and configured on the oob-mgmt-server
• Static MAC address entries are added to DHCP on the oob-mgmt-server for all devices
• A bridge is created on the oob-mgmt-switch to connect all devices eth0 interfaces together
• A private key for the Cumulus user is installed on the oob-mgmt-server
• Public keys for the cumulus user are installed on all of the devices, allowing passwordless ssh
• A NOPASSWD stanza is added for the cumulus user in the sudoers file of all devices

After the topology comes up, we use vagrant ssh to log in to the management device and switch to the cumulus user. The cumulus user is able to access other devices (leaf01, spine02) in the network using its SSH key, and has passwordless sudo enabled on all devices to make it easy to run administrative commands. Further, most automation tools (Ansible, Puppet, Chef) are run from this management server. Most demos assume that you are logged into the out of band management server as the cumulus user.

Note that due to the way we simulate the out of band network, it is not possible to use vagrant ssh to access in-band devices like leaf01 and leaf02. These devices must be accessed via the out-of-band management server.

Prerequisites

Before running this demo or any of the other demos in the list below, install VirtualBox, Vagrant, and Ansible using the installation instructions from their website. The version of Vagrant and Ansible available in your distribution's package manager may be out of date, so installing via the preferred sources is recommended. This example was last tested with Vagrant 1.8 and Ansible 2.0.1.

On an Ubuntu 16.04 box, this can be done with the following commands:

sudo apt-get install git virtualbox software-properties-common
sudo apt-add-repository ppa:ansible/ansible
sudo apt-get update
wget https://releases.hashicorp.com/vagrant/1.8.1/vagrant_1.8.1_x86_64.deb
sudo dpkgi -i vagrant_1.8.1_x86_64.deb 
sudo apt-get install ansible

Available Demos

Typically demos are built upon the Reference Topology shown here using this repository as a starting point and layering device configuration on top.

• Cldemo-docker-quagga -- This demo shows off two ways of putting Quagga into a Docker container to do Layer 3 networking on the hosts.
• Cldemo-automation-puppet -- This demo demonstrates how to write a manifest using Puppet to configure switches running Cumulus Linux and servers running Ubuntu.
• Cldemo-automation-ansible -- This demo demonstrates how to write a playbook using Ansible to configure switches running Cumulus Linux and servers running Ubuntu.
• Cldemo-automation-chef -- This demo demonstrates how to write a set of cookbooks using Chef to configure switches running Cumulus Linux and servers running Ubuntu.
• Cldemo-onie-ztp-ptm -- This demo demonstrates how to configure an out of band management network to automatically install and configure Cumulus Linux using Zero Touch Provisioning, and validate the cabling of the switches using Prescriptive Topology Manager.
• Cldemo-config-routing -- This Github repository contains the configuration files necessary for setting up Layer 3 routing on a CLOS topology using Cumulus Linux and Quagga.
• Cldemo-rdnbr-ansible -- COMING SOON -- This demo shows a topology using 'redistribute-neighbor' to add host reachability directly into a BGP routed fabric.
• Cldemo-roh-ansible -- COMING SOON -- This demo shows a topology using 'Routing on the Host' to add host reachability directly into a BGP routed fabric.
• Cldemo-config-mlag -- COMING SOON

Getting Started

To use one of the demos above, follow the instructions in the README for each repository.

To use the reference topology by itself outside of the above demos, follow the instructions below.

Provision the topology and logging in

git clone https://github.com/cumulusnetworks/cldemo-vagrant
cd cldemo-vagrant
vagrant plugin install vagrant-cumulus
vagrant up
vagrant ssh oob-mgmt-server
sudo su - cumulus

Managing the VMs in the Topology

The topology built using this Vagrantfile does not support vagrant halt or vagrant resume for in-band devices. This means that in order to keep your configuration across Vagrant sessions, you should either save your configuration in a repository using an automation tool such as Ansible, Puppet, or Chef (preferred) or use the hypervisor's halt and resume functionality.

For VirtualBox, these commands are: * VBoxManage controlvm leaf01 poweroff * VBoxManage startvm leaf01 --type headless

Factory-reset a device

vagrant destroy -f leaf01
vagrant up leaf01

Destroy the entire topology

vagrant destroy -f

Provision a Smaller Topology

vagrant up oob-mgmt-server oob-mgmt-switch leaf01 leaf02 spine01 spine02 server01 server02

Customizing the Topology

This Vagrant topology is built using Topology Converter. To create your own arbitrary topology, edit the file topology.dot and add the devices or cables you need and run topology_converter.py in this directory. This will create a new Vagrantfile for you, which is preferred to editing the Vagrantfile manually. For more details on how to make customized topologies, read that project's documentation.

vagrant destroy -f
wget https://raw.githubusercontent.com/CumulusNetworks/topology_converter/master/topology_converter.py
# edit topology.dot as desired
python topology_converter.py topology.dot

Cumulus Linux

Cumulus Linux is a software distribution that runs on top of industry standard networking hardware. It enables the latest Linux applications and automation tools on networking gear while delivering new levels of innovation and flexibility to the data center.

For further details please see: cumulusnetworks.com