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Positioning an IT Conversation

About a week ago, I took my wife’s van to the shop. The main issue was it was making a popping noise in the front end. I only observed the noise when steering sharply and the vehicle was in motion. Typically this occurred when parking. Although I was nearly certain this was an issue with a CV joint, I only told the mechanic about the symptoms we had observed.

The reason I didn’t lead the conversation to the CV joint is that I wanted the mechanic to look at the problem objectively. I knew he was the expert and I wanted him to solve the problem instead of replacing a part. In order to shift the responsibility, I needed the mechanic to diagnose the problem and create a plan of action.

Positioning IT Conversations to Solve Problems

At this point in my career, I have worked in various areas of technology. Over the years, I’ve had customers that tell me exactly what they think they need. In some cases, they’re correct. However, there are times that their solution does not fully solve the problem they are observing. On the other hand, some customers take a smarter approach and explain the problem they are trying to solve.

When Continue reading

Secret Sunday – Jeff Fry

Today’s Secret Sunday is a shout out to the excellent Jeff Fry, aka @FryGuy_PA on Twitter. Jeff blogs at FryGuy.net where among other things he has previously broken the news on upcoming Cisco products a couple of times by close … Continue reading →

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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 This will outline the levels of support a product gets, from new product introduction, through to being superceded, and finally moved to end of support.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

Adding protocols to masscan

The unique feature of Masscan is that it has it’s own TCP/IP stack, bypassing the kernel’s stack. This has interesting benefits, such as being able to maintain a TCP connection with all 30 million HTTPS servers on the Internet simultaneously. However, it means that (at the moment) it’s difficult to write your own protocols. At some point I’m going to add LUA scripting to the system and this technical detail won’t matter, but in the meanwhile, if you want to write your own protocols, you’ll have to know the tricks.

Scalability

The issue Masscan solves is scalability, such as maintaining 30 million concurrent TCP connections. In a standard Linux environment, the system requires about 40 kilobytes per TCP connection, meaning a system would need 1.2 terabytes of RAM to hold all the connections. This is beyond what you can get for standard servers.

Masscan reduces this. At the moment, it uses only 442 bytes per TCP connection – including the memory for difficult protocols like SSL. That’s less than 16-gigabytes of RAM for 30 million concurrent connections.

This is a little excessive, because connections are quick. Even a fast scan of the Internet takes long enough that at any Continue reading

Lync – This Still Blows My Mind

This stuff still totally blows my mind. I was at a restaurant for lunch recently with some colleagues. Service was slow, and as a result I was going to be late back to the office, and I had to join a … Continue reading →

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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 →

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 →

Appropriate Halloween costumes

There has been some debate over Halloween costumes, whether ISIS terrorist garb or hazmat suites are appropriate. Of course they are. Culture responds to current events; everything is fair game.

An example of this are Afghan "war rugs", as pictured below. The one on the left is in response to the old Soviet invasion, and the one on the right is in response to the post-9/11 invasion by the U.S. Rug weavers incorporated things from their environment into the rugs. In particular, the design of the rug on the right comes from leaflets we carpet bombed the country with before invading them.

Indeed, the entire "Halloween" theme is about death. It's just that it got incorporated in our culture long before the Internet enabled wimpy nitpickers from debating what was, or wasn't, appropriate. I'm not sure if the holiday would've survived in the modern politically correct climate.

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 […]

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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!

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

Junos Apply-Path – A Step Closer To Heaven

I have a list of things I mean to blog about, and the Junos Apply-Path feature has been on there for way too long without being actions. As I said when I kicked off the “30 Blogs in 30 Days” … Continue reading →

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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 Google +, 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.

Response: I’m Terrified of My New TV

Smart Televisions are tracking everything you do and sending that data to unknown services: The amount of data this thing collects is staggering. It logs where, when, how, and for how long you use the TV. It sets tracking cookies and beacons designed to detect “when you have viewed particular content or a particular email […]

The post Response: I’m Terrified of My New TV appeared first on EtherealMind.

Make Rip-and-Replace a bit less Creepy

It was a dark and stormy Halloween night and a networking engineer was stuck in a data center facing a Mission Impossible project: replace a failing Cat6500 with a brand-new Nexus 7000. Shouldn’t have been a problem, if only the cables were labeled.