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Category Archives for "Networking"

Worth Reading: Everything you need to know about Linux containers

If you look at the dictionary’s definition of containers, it would be ‘an object for holding and transporting something’. In the same way, Linux containers (mostly abbreviated as LXC in technical language) help in providing virtualisation to the Linux operating system. Tough to comprehend? Wait! Let’s suppose that your enterprise requires to move your code from one environment to another, or that you want to keep your machines and servers tidy and clean. Whether these systems are for development or production purposes, or if you want to try out some different application or development stack on your regular machine without contaminating it, the solution is containers. Linux containers empower enterprises and companies in wrapping and isolating their products with all the necessary files used for running them. —Vinayak Vaid @ opensource.org

The post Worth Reading: Everything you need to know about Linux containers appeared first on rule 11 reader.

25 Under 25: Using the Internet to Make a Difference in Communities

On September 18th in Los Angeles, California, the Internet Society will celebrate a selected group of exceptional young people under the age of 25 who are using the Internet to make a difference in peoples’ lives.

I had the privilege of reading hundreds of submissions and nominations, many of which left me feeling humbled and inspired. The incredible impact these individuals have already had in such a short time is a model for youth around the world and for those of us who already have some years of experience!

Toral Cowieson

On the ‘web: What’s Wrong with BGP

Our guests are Russ White, a network architect at LinkedIn; and Sue Hares, a consultant and chair of the Inter-Domain Routing Working Group at the IETF. They discuss the history of BGP, the original problems it was intended to solve, and what might change. This is an informed and wide-ranging conversation that also covers whitebox, software quality, and more. Thanks to Huawei, which covered travel and accommodations to enable the Packet Pushers to attend IETF 99 and record some shows to spread the news about IETF projects and initiatives.

You can jump to the original post on Packet Pushers here.

The post On the ‘web: What’s Wrong with BGP appeared first on rule 11 reader.

Finding an Efficient VNF Architecture for Next-Generation Telecom Infrastructure

Efficient VNF Architecture Download the HPE White Paper, “”. Global IP traffic expected to triple over the next five years, driven by large-scale mobility, the rise of the Internet of Things (IoT), emerging applications like 4K video and virtual/augmented reality, and smart everything, from connected cars to connected waste-management systems for cities. Telecom providers are facing a broken... Read more →

Libraries Stand for the Internet’s Future and Join the Call to End Shutdowns

Human development cannot happen without inclusive access to information.

This, along with reading and applying knowledge helps us to make better decisions and to create and innovate.

The Internet has brought this much closer. It is easier to create, communicate, and collaborate than ever before. E-commerce has given us new markets, e-journals are allowing us to learn, and e-health is keeping us fit. 

Libraries have seized the opportunity not only to promote online access to information, but to help their users get the best out of the Internet. The welcoming environment and targeted support that they offer is almost as important as the resources to which they provide access. Libraries are also key to improving levels of digital literacy.

Internet access is a prerequisite for achieving this mission. With information providers from the United Nations to local newspapers cutting back on physical printing, the possibility to get online is more essential than ever. Where connections are unreliable, or do not exist, people may even be in a worse position than before. Because of this, all 196 of the UN’s Member States endorsed giving everyone the possibility of Internet access in the 2030 Agenda.

It is therefore unacceptable that governments Continue reading

Libraries Stand for the Internet’s Future and Join the Call to End Shutdowns

Human development cannot happen without inclusive access to information.

This, along with reading and applying knowledge helps us to make better decisions and to create and innovate.

The Internet has brought this much closer. It is easier to create, communicate, and collaborate than ever before. E-commerce has given us new markets, e-journals are allowing us to learn, and e-health is keeping us fit. 

Stephen Wyber

Worth Reading: When the cloud deletes our data

When we talk about people losing their data in the cloud, the conversation typically revolves around hackers, violating terms of service or sites going out of business. However, it is important to remember that in a cloud world we rarely have many rights when it comes to the data we upload or create in the cloud environments provided by many consumer companies and that data can be deleted without us even knowing until after it is far too late. Making matters more complicated, even the biggest brand names don’t necessarily operate their own cloud environments or own the underlying data that makes their services run, meaning that a change anywhere in this pipeline can result in irreplaceable data being lost. —Kalev Leetaru @ Forbes

The post Worth Reading: When the cloud deletes our data appeared first on rule 11 reader.

Episode 11 – Shaking The Status Quo

The network engineering community can get a bit stuck on ideas from time to time, and we take a stab at challenging some of these deeply held beliefs in Episode 11 of Network Collective. Join Ethan Banks, Mike Bushong, and the Network Collective crew as we talk about certifications, multi-vendor environments, orchestration, disaggregation, SDN, cloud, and the network industry hype cycle. Yeah, all of that in one 50 minute package. You’re not going to want to miss this one.

—–
Outro Music:
Danger Storm Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

Ethan Banks
Guest
Mike Bushong
Guest
Jordan Martin
Co-Host
Eyvonne Sharp
Co-Host
Phil Gervasi
Co-Host

Outro Music:
Danger Storm Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

The post Episode 11 – Shaking The Status Quo appeared first on Network Collective.

Episode 11 – Shaking The Status Quo

The network engineering community can get a bit stuck on ideas from time to time, and we take a stab at challenging some of these deeply held beliefs in Episode 11 of Network Collective. Join Ethan Banks, Mike Bushong, and the Network Collective crew as we talk about certifications, multi-vendor environments, orchestration, disaggregation, SDN, cloud, and the network industry hype cycle. Yeah, all of that in one 50 minute package. You’re not going to want to miss this one.

—–
Outro Music:
Danger Storm Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

Ethan Banks
Guest
Mike Bushong
Guest
Jordan Martin
Co-Host
Eyvonne Sharp
Co-Host
Phil Gervasi
Co-Host

Outro Music:
Danger Storm Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

The post Episode 11 – Shaking The Status Quo appeared first on Network Collective.

52% off 299-Piece All-Purpose First Aid Kit – Deal Alert

This full-fledged, easy-to-tote first aid softpack is designed to save time and frustration in the midst of an emergency. It's compact and portable, but contains 299 physician-recommended supplies.  Among the items neatly organized inside the zippered kit is a first aid guide, vinyl gloves, bandages, cold compress, gauze pads, trauma pad, cotton-tipped applicators, first aid tape roll, antiseptics and all three common OTC pain medications. The kit is currently a #1 best seller on Amazon, averages 4.5 out of 5 stars from over 280 customers, and its typical list price of $26.74 has been reduced 52% to just $12.80. Click over to Amazon to see this deal.To read this article in full or to leave a comment, please click here

Save A Whopping $100 on Amazon Echo Right Now By Going Refurbished – Deal Alert

You can pick up Amazon Echo for VERY far below list price, if you're comfortable buying refurbished. Which you can be -- certified refurbished products are tested and certified to look and work like new, and come with warranties. Echo typically lists for $180, or $165 refurbished, but right now it looks like Amazon's letting them go for just $80. Amazon Echo is a hands-free speaker you control with your voice. Echo connects to the Alexa Voice Service to play music, provide information, news, sports scores, weather, and more—instantly. All you have to do is ask. Echo has seven microphones and beam forming technology so it can hear you from across the room—even while music is playing. Echo is also an expertly tuned speaker that can fill any room with 360° immersive sound. When you want to use Echo, just say the wake word “Alexa” and Echo responds instantly. If you have more than one Echo or Echo Dot, Alexa responds intelligently from the Echo you're closest to with ESP (Echo Spatial Perception). See the certified refurbished Amazon Echo on Amazon.To read this article in full or to leave a comment, please click here

Wireless ISPs Spectrum Problem

Wireless ISPs also known as WISP mostly use unlicensed frequency spectrum. Frequency spectrum is the most critical asset for the Mobile and Wireless networks and it is sold in auctions for 100s of millions of dollars.   Frequency spectrum is managed by the governments and governments in general, sell frequency spectrum in auctions.   And […]

The post Wireless ISPs Spectrum Problem appeared first on Cisco Network Design and Architecture | CCDE Bootcamp | orhanergun.net.

NSX-T: Routing where you need it (Part 1)

 

Network virtualization has come a long way. NSX has played a key role in redefining and modernizing networking in a Datacenter. Providing an optimal routing path for the traffic has been one of the topmost priorities of Network Architects. Thanks to NSX distributed routing, the routing between different subnets on a ESXi hypervisor can be done in kernel and traffic never has to leave the hypervisor. With NSX-T, we take a step further and extend this network functionality to a multi-hypervisor and multi-cloud environment. NSX-T is a platform that provides Network and Security virtualization for a plethora of compute nodes such as ESXi, KVM, Bare Metal, Public Clouds and Containers.

 

This blog series will introduce NSX-T Routing & focus primarily on Distributed Routing. I will explain Distributed Routing in detail with a packet walk between the VMs sitting in same/different hypervisors, connectivity to physical infrastructure and multi-tenant routing. Let’s start with a quick reference to NSX-T architecture.

 

NSX-T Architecture

NSX-T has a built-in separation for Management plane (NSX-T Manager), Control Plane (Controllers) and Data Plane (Hypervisors, Containers etc.). I highly recommend going through NSX-T Whitepaper for detailed information on architecture to understand the components and  functionality of each of the planes.

 

Couple of interesting points that I want to highlight about the architecture:

  • NSX-T Manager is decoupled from vCenter and is designed to run across all these heterogeneous platforms.
  • NSX-T Controllers serve as central control point for all the logical switches within a network and maintains information about hosts, logical switches/routers. 
  • NSX-T Manager and NSX-T Controllers can be deployed in a VM form factor on either ESXi or KVM. 
  • In order to provide networking to different type of compute nodes, NSX-T relies on a virtual switch called “hostswitch”. The NSX management plane fully manages the lifecycle of this “hostswitch”. This hostswitch is a variant of the VMware virtual switch on ESXi-based endpoints and as Open Virtual Switch (OVS) on KVM-based endpoints.
  • Data Plane stretches across a variety of compute nodes: ESXi, KVM, Containers, and NSX-T edge nodes (on/off ramp to physical infrastructure).
  • Each of the compute nodes is a transport node & will be a TEP (Tunnel End Point) for the host. Depending upon the teaming policy, this host could have one or more TEPs.
  • NSX-T uses GENEVE as underlying overlay protocol for these TEPs to carry Layer 2 information across Layer 3. GENEVE provides us the complete flexibility of inserting Metadata as TLV (Type, Length, Value) fields which could be used for new features. One of the examples of this Metadata is VNI (Virtual Network Identifier). We recommend a MTU of 1600 to account for encapsulation header. More details on GENEVE can be found on the following IETF Draft. https://datatracker.ietf.org/doc/draft-ietf-nvo3-geneve/

 

Before we dive deep into routing, let me define a few key terms.

Logical Switch is a broadcast domain which can span across multiple compute hypervisors. VMs in the same subnet would connect to the same logical switch. 

 

Logical Router provides North-South, East-West routing between different subnets & has two components: Distributed component that runs as a kernel module in hypervisor and Centralized component to take care of centralized functions like NAT, DHCP, LB and provide connectivity to physical infrastructure.

Types of interfaces on a Logical Router

  • Downlink- Interface connecting to a Logical switch.
  • Uplink– Interface connecting to the physical infrastructure/physical router.
  • RouterLink– Interface connecting two Logical routers.

 

Edge nodes are appliances with a pool of capacity to run the centralized services and would be an on/off ramp to the physical infrastructure. You can think of Edge node as an empty container which would host one or multiple Logical routers to provide centralized services and connectivity to physical routers. Edge node will be a transport node just like compute node and will also have a TEP IP to terminate overlay tunnels.

They are available in two form factor: Bare Metal or VM(leveraging Intel’s DPDK Technology).

 

Moving on, let’s also get familiarized with the topology that I will use throughout this blog series.

I have two hypervisors in above topology, ESXi and KVM. Both of these hypervisors have been prepared for NSX & have been assigned a TEP (Tunnel End Point) IP, ESXi Host: 192.168.140.151, KVM host: 192.168.150.152. These hosts have L3 connectivity between them via transport network. I have created 3 Logical switches via NSX Manager & have connected a VM to each one of the switches. I have also created a Logical Router named Tenant 1 Router, which is connected to all the logical switches and is acting as a Gateway for each subnet.

Before we look at the routing table, packet walk etc., let’s look at how configuration looks like in NSX Manager. Here is switching configuration, showing 3 Logical switches.

Following is the routing configuration showing the Tenant 1 Logical Router.

 

Once configured via NSX Manager, the logical switches and routers are pushed to both the hosts, ESXi and KVM. Let’s validate that on both hosts. Following is the output from ESXi showing the Logical switches and router.

 

Following is the output from KVM host showing the Logical switches and router.

 

NSX Controller MAC learning and advertisement

 

Before we look at the packet walk, it is important to understand how remote MAC addresses are learnt by the compute hosts. This is done via NSX Controllers.  As soon as a VM comes up and connects to Logical switch, local TEP registers its MAC with the NSX Controller. Following output from NSX Controller shows that the MAC addresses of VMs on Web VM1, App VM1 and DB VM1 have been reported by their respective TEPs. NSX Controller publishes this MAC/TEP association to the compute hosts depending upon type of host.

Now, we will look at the communication between VMs on the same hypervisor.

 

Distributed Routing for VMs hosted on the same Hypervisor

 

We have WEB VM1 and App VM1 hosted on the same ESXi hypervisor. Since we are discussing the communication between VMs on same host, I am just showing the relevant topology below.

 

 Following is how traffic would go from Web VM1 to App VM1.

  1. Web VM1 (172.16.10.11) sends traffic to the gateway 172.16.10.1, as the destination (172.16.20.11) is in different subnet. This traffic traverses Web-LS and goes to Downlink interface of Local distributed router running as a kernel module on ESXi Host.
  2. Routing lookup happens on the ESXi distributed router and 172.16.20.0 subnet is a Connected route. Packet gets routed and is put on the App-LS.
  3. Destination MAC lookup for MAC address of App VM1 is needed to forward the frame. In this case, App VM1 is also hosted on the same ESXi, we do a MAC address lookup and find a local MAC entry as highlighted in diagram above.
  4. L3 rewrite is done and packet is sent to App VM1.

Please note that the packet didn’t have to leave the hypervisor to get routed. This routing happened in kernel. Now that we understand the communication between two VMs (in different subnet) on same hypervisor, let’s take a look at the packet walk from Web VM1 (172.16.10.11) on ESXi to DB-VM1 (172.16.30.11) hosted on KVM.

 

Distributed Routing for VMs hosted on the different Hypervisors (ESXi & KVM)

 

  1. Web VM1 (172.16.10.11) sends traffic to the gateway 172.16.10.1, as the destination (172.16.30.11) is in different subnet. This traffic traverses Web-LS and goes to Downlink interface of Local distributed router on ESXi Host.
  2. Routing lookup happens on the ESXi distributed router. Packet gets routed and is put on the DB-LS. Following output show the distributed router on ESXi host and it’s routing table.

  1. Destination MAC lookup for MAC address of DB VM1 is needed to forward the frame. MAC lookup is done and MAC address of DB VM1 is learnt via remote TEP 192.168.150.152. Again, this MAC/TEP association table was published by NSX Controller to the hosts.

  1. ESXi TEP encapsulates the packet and sends it to the remote TEP with a Src IP=192.168.140.151, Dst IP=192.168.150.152.
  1. Packet is received at remote KVM TEP 192.168.150.152, where VNI (21386) is matched. MAC lookup is done and packet is delivered to DB VM1 after removing the encapsulation header.

A quick traceflow validates the above packet walk.

This concludes the routing components part of this blog. In the next blog of this series, I will discuss multi-tenant routing and connectivity to physical infrastructure.

Continue reading

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