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Category Archives for "Networking"

In Praise of Support Lifecycles

If you’re just starting out working with ‘Enterprise’ products, you may not have come across Support Lifecycles. It’s important to know what these are, and how it affects you. They can have both a positive & a negative impact on when and why you choose to upgrade systems.

What Are Support Lifecycles?

Developers would like to only support the latest version. But customers can’t/won’t always run the latest version. They need to know that they can expect a certain level of support for the version they’re running. As a compromise, software vendors will publish a support lifecycle policy. This will outline the levels of support a product gets, from new product introduction, through to being superceded, and finally moved to end of support. Typical phases include:

  • General Support: Product is in General Availability phase, and is fully supported. You can log support cases, search KB articles, and expect both functionality enhancement and bugfix patches. The current product version will always be in this phase, and typically 1-2 major versions behind will also be included.
  • Limited Support: You can log a support case, and we’ll try to help, but we’re not planning any new patches, and you’ll probably get a suggestion Continue reading

Network Break 19

Continuing our regular look at the news in Networking and Cloud.

Author information

Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus.

The post Network Break 19 appeared first on Packet Pushers Podcast and was written by Greg Ferro.

Shellshock: One Month On

Shellshock was released a little over a month ago, to wide predictions of doom & gloom. But somehow the Internet survived, and we lurch on towards the next crisis. I recently gave a talk about Shellshock, the fallout, and some thoughts on wider implications and the future. The talk wasn’t recorded, so here’s a summary of what was discussed.

Background: NZ ISIG: Keeping it Local

The New Zealand Information Security Interest Group (ISIG) runs monthly meetings in Auckland and Wellington. They’re open to all, and are fairly informal affairs. There’s usually a presentation, with a wide-ranging discussion about security topics of the day. No, we don’t normally discuss “picking padlocks, debating whose beard or ponytail is better or which martial art/fitness program is cooler.”

Attend enough meetings, and sooner or later you’ll be called upon to present. I was ‘volunteered’ to speak on Shellshock, about a month after the exploit was made public. I didn’t talk about the technical aspects of the exploit itself – instead I explored some of the wider implications, and industry trends. I felt the talk went well, mainly because it wasn’t just me talking: everyone got involved and contributed to the discussion. It would be a bit Continue reading

The Etymology of Elephant and Mice Flows

Over the past 3-4 years, the term elephant flows has been used to refer to east-west (machine-to-machine) traffic, such as vMotion, Migration, Backup, and Replication. The term mice flows is used to refer to north-south (user-to-machine) traffic. Why are we using these terms all of a sudden and did they come from? Wikipedia states “It is not clear who … Continue reading The Etymology of Elephant and Mice Flows

White Box switch readiness for prime time

Matthew Stone runs Cumulus Networks switches in his production network. He came on the Software Gone Wild podcast recently to talk about his experiences. Cumulus, Pica8, and Big Switch are the three biggest proponents of white box switching. While Pica8 focuses on the Linux abstractions for L2/L3, Pica8 focuses more on the OpenFlow implementation, and Big … Continue reading White Box switch readiness for prime time

JNCIE-ENT Prep Guide has been published!

Just a quick note on a Friday afternoon about The Unofficial JNCIE-ENT Pre Guide to let you know that it has now been published. You may order a copy at LeanPub, and to kick it off here is a 25% off coupon – http://fryguy.me/JNCIEENTWB The guide is is over 500 pages of JNCIE study goodness for […]

The Network Iceberg

The impact of compute virtualization on the data center network has been profound. There are more virtual ports then physical ports. That simple measurement overshadows any other disruption in networking. We arrived at this transformation as a result of significant adoption of OS virtualization. The next revision of compute virtualization is the application. The last significant bastion of efficiency is to ... The post The Network Iceberg appeared first on NetworkStatic | Brent...

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Plexxi Pulse—Don’t Be Spooked by Big Data

We are getting into the Halloween spirit here at Plexxi—check out this Plexxi pumpkin carved by our talented marketing manager, Khoa Ma!

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Jack-o-lanterns aside, we know the thought of navigating trends like the Internet of Things and Big Data can be frightening, especially if you are unsure of how to approach them. As these trends gain popularity and deployments increase, IT architects often worry about increased activity on already taxed infrastructures. Our own Mike Bushong is our resident expert on this topic and he penned an interesting blog post this week on networking’s atomic unit and “going small to scale up.” Creating smaller units of capacity makes the network easier to manage, and most importantly, scale. It’s definitely worth a read before heading out to trick-or-treat.

In this week’s PlexxiTube of the week, Dan Backman explains failure scenarios in case of hardware or software outages in a Plexxi pod design.

Don’t Engineer a Mess

Network architect Brian Heder contributed an article to Network World this week on the importance and challenges of simplicity in computer network design. While I think Heder’s list is solid, I would add an additional obstacle to network simplicity: customization. Avoid making your network environment Continue reading

Musing: Subscription License Economics


The rise of software licensing in networking changes some of my assumptions about the 5 year cost of ownership of products. Roughly, lets assume that you are buying virtual appliances like firewalls, DNS/DHCP, IDS/IPS, proxy servers and load balancers and that you pay some type of yearly license to use the product. Capital Upfront The legacy […]

The post Musing: Subscription License Economics appeared first on EtherealMind.

Calculating burst size for class-of-service

Burst sizes need to be calculated if you are implementing policers or shapers on Junos devices so that the policer or shaper can control the flow of traffic appropriately.  Too small a burst size and TCP applications will have terrible throughput.  Too large a burst size and the policer won’t be very effective – the bursts are so large they cancel out the effect of the policing because as one burst ends another one is just about to begin.

The situation is described reasonably well on the Juniper site here, and also in O’Reilly’s excellent MX book.  But in both places the mathematics of the calculation is hidden in a paragraph of text – not written out properly and showing the workings.  That makes for confusion in my mind.

It’s actually a fairly easy calculation, but isn’t presented well.  I finally sat down to work out what it meant.

The easy way to calculate burst size for low bandwidth (i.e. T1/E1 etc) interfaces is 10 times the MTU of the interface.   The problem with this is (as you see in figure 3 in the Juniper link above) that on 1500-byte Ethernet this Continue reading

Halloween Career Advice from the Damned

“Now, as you look through this document you’ll see that I’ve underlined all the major decisions I ever made to make them stand out. They’re all indexed and cross-referenced. See? All I can suggest is that if you take decisions that are exactly opposite to the sort of decisions that I’ve taken, then maybe you […]

Author information

Glen Kemp

Professional Services Consultant at Fortinet, Inc

Professional Services Consultant. Designing & deploying “keep the bad guys out” technologies. Delivering elephants and not hunting unicorns.

Please free to add me on , follow me on Twitter or check out my other blogs on Fortinet Blog, sslboy.net and SearchNetworking.

The post Halloween Career Advice from the Damned appeared first on Packet Pushers Podcast and was written by Glen Kemp.

PDU-12C

"After all, what's the best part of Halloween?" Jimmy pleaded over the phone. He was trying yet again to convince Tom to skip work for the night and head over to the party he was throwing. Tom and Jimmy were good friends, but he already knew how the conversation was going to end.

"I dunno, the candy?" Tom played dumb.

"No, the eye candy! I'm telling you bro, you don't want to miss it. Rachel will be there." Jimmy sang the last bit tauntingly.

"I told you," Tom countered. "I've got work." It was around 6pm now, and he was just pulling into the parking lot outside the data center where he planned to spend the night recabling several racks of equipment. The scariest part of his Halloween would be picking through years' worth of undressed patch cabling.

"I don't get why you have to do that shit at night anyway. Why can't you do it during the day when you're stuck at work anyway?" Jimmy prodded.

Tom parked across from the building's entrance and turned off his car. Other than a couple vehicle belonging to the operations staff, the parking lot was deserted. He Continue reading

Happy Tenth Anniversary Arista Networks!

Every year at Arista has been filled with milestones and enriching memories. I want to acknowledge and thank each and every Arista well-wisher for contributing to this incredible experience. So let’s take a walk together down memory lane and look back on our journey from start-up to a now public company. I think of Arista’s first decade as being comprised of three phases:

2004+ Our Humble Beginnings:

Funded in a unique fashion, without traditional venture capital investment, Arista (first called Arastra, located on Arastradero road in Palo Alto) was placed in a unique position. Our founders, Andy and David, were our funders, too, and they cared deeply about building the company with the right technology foundation. Ken Duda, also a founder and our EOS software genius, brought a radical, resilient and programmable network-OS for modern, disruptive applications. Bringing some of the best and brightest engineering minds together resulted in an innovative network-wide operating system that challenged legacy enterprise switching vendors. Andy Bechtolsheim and I launched the company officially in October 2008. With just 50 engineers we gained 50 customers by the end of 2008, proving what small focused teams could accomplish. Our early adopters welcomed us as a breath of Continue reading

Show 210 – SPB Implementation Fundamentals

Dominik and Ricki Cook join Packet Pushers Greg Ferro and Ethan Banks in a hands-on exploration of Shortest Path Bridging, IEEE 802.1aq. Most of us have had our hands on Avaya gear that does SPB — Ethan in the lab, and Dominik + Ricki in production environments. We go through the basic goals, setup, and commands […]

Author information

Ethan Banks

Ethan Banks, CCIE #20655, has been managing networks for higher ed, government, financials and high tech since 1995. Ethan co-hosts the Packet Pushers Podcast, which has seen over 2M downloads and reaches over 10K listeners. With whatever time is left, Ethan writes for fun & profit, studies for certifications, and enjoys science fiction. @ecbanks

The post Show 210 – SPB Implementation Fundamentals appeared first on Packet Pushers Podcast and was written by Ethan Banks.