I am glad to announce that Russ White and I have been preparing a CCDE Practical Exam ( Lab Exam ) Scenario. This is the most realistic scenario available anywhere.Because it is not just prepared by a CCDE but one of the founder of the exam involved. Disclosure : This is not asked in the CCDE… Read More »
The post Russ White – Orhan Ergun CCDE Practical Exam Scenario appeared first on Network Design and Architecture.
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If software developers and network driver writers can make their own packets, can’t you? Ah, right...you’re not a developer. Your coding-fu is weak, as is mine. Still, there’s hope for us in an open source tool called Ostinato. Ostinato calls itself “Wireshark in reverse.” With Ostinato, you can make your own packets, custom crafting them any way you like. Today on the Packet Pushers Priority Queue, we’re talking with one of the Ostinato creators, Srivats P.
The post PQ Show 52 – Using Ostinato To Craft Your Own Packets appeared first on Packet Pushers Podcast and was written by Ethan Banks.
Of course, routing on a per application (or a per packet) basis provides more optimization, but it also adds more state in the control plane, and it increases the speed at which that state changes. In my forthcoming book on network complexity, I’m going to work around a model of state/speed/surface, with a side of optimization, to gain an understanding of network complexity and how to manage it.
The post Worth Reading: SD-WAN and Per Application Routing appeared first on 'net work.
Last week during a casual conversation I overheard a colleague saying: "The Linux network stack is slow! You can't expect it to do more than 50 thousand packets per second per core!"
That got me thinking. While I agree that 50kpps per core is probably the limit for any practical application, what is the Linux networking stack capable of? Let's rephrase that to make it more fun:
On Linux, how hard is it to write a program that receives 1 million UDP packets per second?
Hopefully, answering this question will be a good lesson about the design of a modern networking stack.
CC BY-SA 2.0 image by Bob McCaffrey
First, let us assume:
Measuring packets per second (pps) is much more interesting than measuring bytes per second (Bps). You can achieve high Bps by better pipelining and sending longer packets. Improving pps is much harder.
Since we're interested in pps, our experiments will use short UDP messages. To be precise: 32 bytes of UDP payload. That means 74 bytes on the Ethernet layer.
For the experiments we will use two physical servers: "receiver" and "sender".
They both have two six core 2GHz Xeon processors. With hyperthreading (HT) enabled Continue reading
The Packet Pushers discuss Smart Labs on AWS & Google using Ravello's nested virtualization with Gil Hoffer, VP of R&D, & Navin Thadani, Sr. VP of Products.
The post Show 241 – Smart Labs on Public Cloud with Ravello – Sponsored appeared first on Packet Pushers Podcast and was written by Ethan Banks.
Before we proceed with TDD framework build it is important to have the development environment setup. In our case it will consist of two major components:
To simplify things I will run both of these environments on the same Virtual Machine. For network simulation I will use UnetLab, a wonderful product developed by Andrea Dainese. Currently, UnetLab is distributed as an OVA package and is available for free download on the website. To simulate network devices I will run IOU which will be interconnected to form a simple network. Finally, I will show how to setup development environment with Ansible, git and Python.
Continue readingOne of the most interesting things about SD-WAN is the level of real differentiation between the different vendors that has actual business outcomes. Let me explain, most SD-WAN vendors are using overlay networks to bypass the restrictions and limitations of IP routing. A few of the features in common are: multi-path networking dynamic and temporal […]
The post Differentiation in Software Defined WAN appeared first on EtherealMind.
We’ve secretly replaced Tom with Mike Rowe. Let’s see if anyone notices…
Cisco Live 2015 is in the books. A great return to San Diego. A farewell from John Chambers. A greeting from Chuck Robbins (@ChuckRobbins). And a few other things.
The absolute best part of Cisco Live is the community that has grown from the social media attendees. More than once I heard during the week “I can’t believe this used to be 20-30 people!”. The social community continues to grow and change. Some people move on. Others return from absence. Still others are coming for the first time.
The Cisco Live social community is as inclusive as any I have seen. From the Sunday night Tweetup to the various interactions throughout the week, I’m proud to be a part of a community that strives to make everyone feel like they are part of a greater whole. I met so many new people this year and marveled at the way the Social Media Hub and Meetup Area were both packed at all hours of the day.
That being said, the community does have some concerns. Some of them are around Continue reading
