VIRL and CML – Overview

Cloud Platforms, Networking & SDN, , ,

CML(Cisco Modeling lab) and VIRL(Virtual Internet and Routing lab) are Network modeling platforms from Cisco. I have been trying this out for the last 2 weeks and I am very impressed by what it can do. I feel that the potential for this platform is so huge that it will create a fundamental impact in the Networking industry. Currently, the simulation is limited mainly to Cisco devices though I have seen Juniper and Vyatta images in the VM list. In the next series of blogs, I will walk through some of the following topics:

  • What is CML, VIRL? Architecture and Software components.
  • How to get started? Installation and Quickstart.
  • Examples/Use cases that I tried. L3, L2, management.

Difference between CML and VIRL:

CML is a code branch of VIRL that has been enhanced to provide more scale, VIRL has a 15 node limit. CML customers get Cisco TAC support. CML is focussed towards Enterprise customers, while VIRL is focussed on individuals and training institutions. Obviously, VIRL is much cheaper than CML. VIRL has different prices based on personal or academic use.

Since I work in Cisco, I didnt have to pay any money to try out CML and VIRL. Going forward, I will use the term VIRL to describe the Network Modeling platform. If there are any CML specifics, I will mention those.

VIRL/CML Overview:

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VMWare Player and VM Networking

Storage & Virtualization,

VMWare Player is the Virtualization software/hypervisor provided free of charge by VMWare. Player is for personal use. Paid versions are available as VMWare Player Pro or VMWare Workstation. Following link covers the differences between different editions. I have used Virtualbox for most of my VM needs. There were few recent scenarios where I had to use VMWare Player and in this blog, I will share some things that I learnt as part of this process.

Networking Options:

  1. Bridged – This is equivalent to the Bridged option provided by Virtualbox. This is present by default. VMnet0 is used for this.
  2. NAT – This is equivalent to the NAT option provided by Virtualbox. This is available as VMNet8 in the host machine and is present by default.
  3. Host only – This is equivalent to Host only option provided by Virtualbox. The difference is that only 1 network is present by default. This is available as VMNet1 is the host machine. To change the default subnet created, we need vmnetcfg utility.
  4. Custom – This is a variation of Host only option where we can create more networks and associate with VMNet2, 3, etc. This is not available by default and we need vmnetcfg utility to create custom networks.
  5. LAN Segments – This is similar to Custom network. Here, there is no host connectivity and no dhcp servers. Advantage with LAN segment is we dont have limit on the number of networks.

vmnetcfg utility:

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OpenNSL – Thoughts

Networking & SDN, ,

Recently, Broadcom has opensourced API for their network switching asic as part of OpenNSL project. I tried to dig little deep into what it really means and this blog is a result of that.

What is really Opensourced?

Following picture from Broadcom OpenNSL project clearly illustrates this:

opennsl1
Following are some notes:

  • OpenNSL is a layer on top of Broadcom SDK. Broadcom SDK is not opensourced, only the OpenNSL layer is opensourced.

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Kubernetes and Google container engine

Cloud Platforms, Containers & Kubernetes, , ,

In this blog, I will cover the Google container engine service that I tried out.

Pre-requisites:

  • Need Google cloud account.
  • Install Google cloud SDK.

Google container engine is not available in the normal gcloud SDK installation. To use container engine service, we need to update preview component.

$ gcloud components update preview

I followed the 2 examples mentioned in the container engine documentation.
WordPress application:
In this example, we create a cluster which has a single master and single worker node. We create a pod running WordPress container in the cluster and expose the WordPress service to external world. Since there is only 1 pod, we dont create a service.
Following are the commands used:

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Kubernetes on Google cloud

Cloud Platforms, Containers & Kubernetes, , ,

In this blog, I will cover the steps to run Kubernetes on Google compute VM. I used the steps mentioned here.

Pre-requisites:

  • Need Google cloud account.
  • Install Google cloud SDK.

First step is to download and unzip Kubernetes tar file from here.
Next, we create the cluster using the provided script.

export KUBERNETES_PROVIDER=gce
./cluster/kube-up.sh

The above script creates the clusters with 1 master and 4 minions. Also, it sets up all necessary services both in master and minions node.
Lets look at the VMs created:

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Kubernetes – Overview

Cloud Platforms, Containers & Kubernetes, , , ,

Earlier, I had written a blog on Docker Orchestration. This is a pretty new area and different solutions are being developed to address this problem. Few weeks back, I had written a blog on AWS EC2 Container service. Kubernetes is a Docker Orchestration engine used to manage a cluster of Containers. Google initially developed Kubernetes, currently its an open source project and source code is available here. Google Cloud’s Container engine uses Kubernetes to manage Docker Containers. Kubernetes can be used standalone or with any Cloud service like AWS, EC2.

Kubernetes basics:

Following are basic building blocks within Kubernetes:

  • Cluster(master and minion) – This is the cluster of machines where Container services are launched on. There is 1 master node and the other nodes are called as worker nodes or minions. The master node runs etcd configuration database service, scheduler to schedule the containers, api server for external clients to talk to, replication controller to manage the state of containers. The minion node runs a slave agent to talk to the master node.
  • Pods – can be a single container or a collection of containers. Containers within a pod share same characteristics and are brought up and teared down together. They are normally launched on same minion. An example could be a pod containing redis master and slave database containers. Pod configuration is defined as a json file.
  • Service – Service is an abstraction over Pod that is useful for Service discovery and exposing environment variables to other services. Example could be a database service exposing port numbers to web service.
  • Labels – Labels are used with Pods and Services for easier management of Containers through filters. Rather than managing individual Pods and Services, Containers can be managed at Label level. For example, we can say destroy all “frontend” labels.

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Google Cloud – Getting started

Cloud Platforms, ,

I have used AWS for most of my Cloud related needs. Recently, I tried out Google Cloud and I will share some of my experiences with Google Cloud in this blog.

The easiest way to get started is to signup for the 60 day trial. This gives 300$ of credit to use Google Cloud for 60 days. It is necessary to register using a credit card.

Google cloud services can be accessed either using Developer’s console, CLI, SDK. It is needed to create atleast a single project to get started. First, I created a project using the Developer’s console. Developer’s console can be accessed from here.

Installing and using gcloud SDK:

Use the procedure here to install SDK.
Following are the steps that I did to install SDK in Ubuntu 14.04 VM running in Virtualbox:

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Opencompute Networking – Facebook Contributions

Networking & SDN, ,

Earlier, I had written a blog on Opencompute networking project. There were few recent contributions from Facebook to Opencompute. In this blog, I wanted to capture major Opencompute Networking contributions from Facebook. I see these contributions as pretty significant in the context of White box switches.

Wedge hardware design for TOR:

The goal here was to develop modular switches where any hardware component of the switch can be replaced independently. Servers in the TOR use the Group Hug architecture where standard connector is used to connect the servers to the motherboard. This can allow a easier change of processor.

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AWS ECS(EC2 Container service)

Cloud Platforms, Containers & Kubernetes, ,

I recently tried out AWS ECS(EC2 Container service). In this blog, I will provide overview of EC2 container service, some hands-on stuff I tried and my experiences with ECS. AWS ECS is available as a preview currently with only CLI interface. I assume general availability with web interface will be available soon. Amazon does not charge separately for the ECS service, instances used for containers will be charged appropriately. I have a AWS free-tier account and I was able to try the ECS with the free-tier account.

Pre-requisites:

  • Familiarity with Containers and Docker. You can refer to my blog on Docker series.
  • Familiarity with AWS services. You can refer to my previous blogs on AWS overview and how to access AWS services.
  • For the hands-on stuff, you need to have atleast a free-tier account with AWS. AWS cli needs to be installed since ECS is available only with a CLI interface currently.

Overview of ECS:

I had written a blog earlier on Docker Orchestration. ECS is a Docker Container Orchestration service that provides the following functionalities.

  • Allows to deploy Containers across a cluster of hosts using either AWS scheduler or integrate with third party schedulers like Mesos.
  • Allows management of an application that spans multiple containers rather than just managing containers.
  • Provides high availability for Containers by monitoring Container health.

Following are components of ECS:

  • Cluster – Logical entity that contains multiple EC2 instances. Instances within the container can be of different types.
  • Container instances – Each instance is an EC2 instance with Docker and Container agent pre-installed and is available as AWS AMI image. Container agent registers itself to the cluster and it monitors health of the Containers in the host. AWS is open-sourcing the Container agent project and its available in github.
  • Tasks – Tasks contains the application definition, resources needed and it can span multiple containers. Task definitions are specified in json format.
  • ECS Master – This manages everything. ECS master is responsible for scheduling the containers and also for talking to the container agent to get the health of container instances. When ECS master schedules the containers, it takes into account resources needed for the container and the resources available in the container instance.

ECS hands-on:

Most of the steps below are as mentioned in AWS ECS developer guide.

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