Cisco offers ACI alternative for Nexus 9000 switches

Cisco is adding a new control plane capability to its Nexus 9000 switches for customers not yet opting for or needing a full-blown application policy infrastructure.Cisco’s BGP Control Plane for VXLAN is designed to appeal to operators of multitenant clouds looking for familiar BGP routing protocol features with which to scale their networks and make them more flexible for the demands of cloud networking. VXLAN, which scales VLAN segmentation to 16 million endpoints, does not specify a control plane and relies on a flood-and-learn mechanism for host and endpoint discovery, which can limit scalability, Cisco says.To read this article in full or to leave a comment, please click here

Path MTU discovery in practice

Last week, a very small number of our users who are using IP tunnels (primarily tunneling IPv6 over IPv4) were unable to access our services because a networking change broke "path MTU discovery" on our servers. In this article, I'll explain what path MTU discovery is, how we broke it, how we fixed it and the open source code we used.

Tunnel

source

First there was the fragmentation

When a host on the Internet wants to send some data, it must know how to divide the data into packets. And in particular it needs to know the maximum size of packet. The maximum size of a packet a host can send is called Maximum Transmission Unit: MTU.

The longer the MTU, the better for performance, but the worse for reliability, because a lost packet means more data to be retransmitted and because many routers on the Internet can't deliver very long packets.

The fathers of the Internet assumed that this problem would be solved at the IP layer with IP fragmentation. Unfortunately IP fragmentation has serious disadvantages and it's avoided in practice.

Do-not-fragment bit

To work around fragmentation problems the IP layer contains a "Don't Fragment" bit on every IP packet. Continue reading

A Baker’s Dozen, 2014 Edition

bakersdozen-f

As is our annual tradition, this blog provides a year-end review of how the Internet providers at the top of our IP Transit Intelligence global rankings (formerly, Renesys’ Market Intelligence) fared over the previous year.  The structure and performance of the Internet remains a huge blind spot for most enterprises, even those critically dependent on it for business operations.  Whether it’s the next 3 billion people coming online, poor performance due to suboptimal routing, or security breaches of a trust-based Internet infrastructure, Dyn provides critical insight into the structure and performance of the Internet, both real-time and historical, via its Internet Intelligence products.  More importantly, our services help our customers make the changes necessary to optimize Internet availability, reliability, and reach.  This blog reviews a single very small slice of our data related to the sizes of the top global players as it pertains to the markets and customers they serve.

Back in 2008, we chose to look at the 13 providers that spent at least some time in the Top Ten that year, hence the name “Baker’s Dozen“.  We repeated that exercise in 2009, 2010, 2011, Continue reading

From VIRL to IOU and Back

When VIRL first came out everyone jumped on the bandwagon, including myself. Some of us have had it before it was officially released to the public. Cisco’s VIRL is really a good piece of software,...

[[ Summary content only, you can read everything now, just visit the site for full story ]]

From VIRL to IOU and Back

When VIRL first came out everyone jumped on the bandwagon, including myself. Some of us have had it before it was officially released to the public. Cisco’s VIRL is really a good piece of software,...

[[ Summary content only, you can read everything now, just visit the site for full story ]]

From VIRL to IOU and Back

When VIRL first came out everyone jumped on the bandwagon, including myself. Some of us have had it before it was officially released to the public. Cisco’s VIRL is really a good piece of software,...

[[ Summary content only, you can read everything now, just visit the site for full story ]]

Data-Driven RESTful API Testing for Java

This post is a Zombie that I'm resurrecting from my drafts. I"m not doing any Java these days, but hopefully this post might be useful to somebody

In my quest to get better code coverage for the OVSDB project in OpenDaylight I started to look at increasing coverage for the REST API. It's pretty difficult to test this in an efficient way (lines of code) and frameworks like Robot would have been easier to use. The disadvantage with using an external test framework is that code coverage (using a plugin like JaCoCo) would not be logged. Therefore I harnessed my Junit-Jitsu and found a solution that lives in the JVM

Data-Driven RESTful API Testing for Java

This post is a Zombie that I'm resurrecting from my drafts. I"m not doing any Java these days, but hopefully this post might be useful to somebody

In my quest to get better code coverage for the OVSDB project in OpenDaylight I started to look at increasing coverage for the REST API. It's pretty difficult to test this in an efficient way (lines of code) and frameworks like Robot would have been easier to use. The disadvantage with using an external test framework is that code coverage (using a plugin like JaCoCo) would not be logged. Therefore I harnessed my Junit-Jitsu and found a solution that lives in the JVM

The Scenario

Lets take a very simple example REST API

GET, PUT: /v2/foo

Step 1: The Solution Components

The solution uses the following components

The parameterized runner will run run a test multiple times given a bunch of parameters. This way we can write one test, specifiy our parameters in YAML and let JUnit do the hard work!

Step 2: Writing the YAML file

Here's a sample YAML file:

---
- name: testGetAllFoo
  operation: GET
  uri Continue reading

From VIRL to IOU and Back

When VIRL first came out everyone jumped on the bandwagon, including myself. Some of us have had it before it was officially released to the public. Cisco’s VIRL is really a good piece of...

[[ Summary content only, you can read everything now, just visit the site for full story ]]

Data-Driven RESTful API Testing for Java

This post is a Zombie that I'm resurrecting from my drafts. I"m not doing any Java these days, but hopefully this post might be useful to somebody

In my quest to get better code coverage for the OVSDB project in OpenDaylight I started to look at increasing coverage for the REST API. It's pretty difficult to test this in an efficient way (lines of code) and frameworks like Robot would have been easier to use. The disadvantage with using an external test framework is that code coverage (using a plugin like JaCoCo) would not be logged. Therefore I harnessed my Junit-Jitsu and found a solution that lives in the JVM

Explaining the Game of Sony Attribation

Attribution is a blame game. It’s not about who did it, but who is best to blame. Ambulance chasing lawyers sue whoever has the most money, not who is most responsible. I point this out because while the U.S. “attributes” the Sony hack to North Korea, this doesn’t mean North Korea did the attack. Instead, it means that North Korea was involved enough to justify sanctions. It still leaves the question of “who did it” unresolved.

The situation is comparable to the recent terrorist attack on Charlie Hebdo in France. Two brothers committed the crime, but “Al Qaeda of the Arabian Peninsula” (AQAP) claims credit. The precise facts are murky, but we have a good idea what happened. While AQAP probably provided some training, it appears the attack was conceived, planned, financed, and executed by the two brothers themselves without AQAP help. The brothers took out bank loans and purchased the weapons from the criminal (not terrorist) underground. They appear to have planned the attacks with a friend from ISIS (the Islamic “Caliphate”), an organization hostile to AQAP. It appears most of their training was in France rather than during their trip to AQAP camps in Yemen. AQAP waited Continue reading

Cisco MDS Port-Security with Auto-Learning

I have been learning about Cisco MDS port-security recently and I have been struggling with this feature because it was different from what I expected. What I was expecting was something very similar (and easy) like the good old Ethernet Port-Security feature. This is clearly not the case and I will show you how to […]

A lesson in the corrupt press

In the last few days, both President Obama and Republican presidential candidate Chris Christie made similar statements about vaccination. They both said that parents should absolutely vaccinate their children, but that it's still ultimately the parent's choice (and not government's). While the statements were similar, the press reported these stories completely differently. They praised Obama for calling for vaccination, and lambasted Christie for siding with anti-vaxxers on parental choice.

The White House's statement is the following:
The President certainly believes that these kinds of decisions are decisions that should be made by parents, because ultimately when we’re talking about vaccinations, we’re typically talking about vaccinations that are given to children.  But the science on this, as our public health professionals I’m sure would be happy to tell you, the science on this is really clear.
Christie's statement is the following:
Mary Pat and I have had our children vaccinated and we think that it’s an important part of being sure we protect their health and the public health. I also understand that parents need to have some measure of choice in things as well, so that’s the balance that the government has to decide.
The thing is, not only is Continue reading

Why Network Engineering Is a Top Job for 2015

Why Network Engineering Is a Top Job for 2015

by Brian Boyko, Contributor - February 3, 2015

According to career marketplace Glassdoor, one of the top 25 best jobs in America for 2015 is “network engineer.” No surprises here. Network engineering is a high growth industry: interesting and challenging work, tons of autonomy in how to solve problems and come up with solutions, well paying, and most importantly, the knowledge that you’re building something and bringing creations to life.   

Indeed, the complexities of modern networks make network engineers indispensable, with the mix of virtual and real servers, cloud services and data centers, and of course, the integration of SDN into your network. On a good day, you get that rush of power from doing what is essentially mad science. 

It should be noted that network engineering was one of eight IT-based jobs to crack the top 25. Clearly, technical skills are in demand. 

You know, it brings me back to Nicholas Carr’s books “Does IT Matter?” and “The Big Switch,” which expanded on a 2003 article he wrote in Harvard Business Review claiming that “IT Doesn’t Matter.” Essentially, Carr predicted Continue reading

Using ansible and dynamic Amazon EC2 inventory management on #AWS

Screenshot_2015-02-03_13.00.10Brandon Chavis, an AWS Partner Solutions Architect, has a great post over on the AWS blog titled "Getting Started with Ansible and Dynamic Amazon EC2 Inventory Management" today.

From the post:

Today, the options for configuration and orchestration management seem nearly endless, making it daunting to find a tool that works well for you and your organization. Here at AWS, we think Ansible, an APN Technology Partner, provides a good option for configuration management due to its simplicity, agentless architecture, and ability to interact easily with your ever-changing, scaling, and dynamic AWS architecture.

Instead of having to push an agent to every new instance you launch via userdata, roll an agent into an AMI, or engage in similarly management-intensive deployments of your config management software, the Ansible framework allows administrators to run commands against Amazon Elastic Compute Cloud (Amazon EC2) instances as soon as they are available, all over SSH. This document intends to examine ways that your Amazon EC2 inventory can be managed with minimal effort, despite your constantly changing fleet of instances.

Read the full post here.

 

NFD8 Recap: Nuage Networks – One to Watch

Last fall, I attended the Tech Field Day NFD8 event, and one of the presenting companies was Nuage Networks. This was actually the second time I’d seen Nuage present at an NFD event, the first one being NFD6 a year earlier. Upon my return from NFD8, I did a short write-up of each presenting sponsor for my coworkers at H.A. Storage Systems to keep them informed. The following is my recap of Nuage Networks after their presentation in which I explain why I think Nuage is really on-target with their SDN solution and is definitely a solution to keep an eye on.

Nuage Networks is definitely an SDN company to watch. They are a subsidiary of Alcatel-Lucent (sort of like Cisco’s Insieme but apparently there are no current plans to spin them back in), so they have good financial backing — better than many startups. They have a very mature vision of complete end-to-end SDN with automated deployment tools and fabric-wide management, but they’ve gone beyond what several of the competitors have to look at massive, massive scaling as a core requirement.
Rather than using VXLAN or some other new protocol for things like federation between fabrics, they simply use Continue reading

The Cisco Network Programmability (SDN) Intro Course

Four network programmability certs, two exams for each cert (with matching video courses for each exam) – plus one introductory video. Today’s post discusses that introductory video course, namely:

  • Introducing Network Programmability Fundamentals

No muss, no fuss – jump into the post for more details.

Overview

Cisco recommends their “Introducing Network Programmability Fundamentals” course to anyone who is:

  • New to SDN
  • New to network programmability

Basically, before diving into the other exams and courses, this introductory course sets the stage. Do you have to watch it to get the certifications? No. Can you benefit? Sure. But if you do want to use this course, take it first in sequence, before taking the other Cisco network programmability courses.

 

Figure 1: Big (and Obvious) Progression from the Introductory Course

 

Covering the bases, this list gives the highlights of the course:

  • Six videos of approximately 1 hour each
  • Six different presenters (one per video)
  • 6 month lease
  • $59 (at least when I looked just now)
  • No exam associated with the course – it’s just fundamental background
  • My recollection (with no way to confirm) is that the version of the course I see when writing this post came out late 2013.

To Continue reading

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