Teaching Without a Teaching Degree

So, let’s say you’re a technical admin, engineer, architect, whatever (most of you are). It’s probably safe to say that nearly all of you (I fit into this) have an occupation where our primary ongoing task is some combination of system or network administration, design, software and hardware engineering work, including build-out or troubleshooting, etc. Maybe it’s all of these. No matter what, it’s a safe assumption that a big, or maybe even number one reason we all get paid is because we’re really good at the technical work.

Teaching Without a Teaching Degree

So, let’s say you’re a technical admin, engineer, architect, whatever (most of you are). It’s probably safe to say that nearly all of you (I fit into this) have an occupation where our primary ongoing task is some combination of system or network administration, design, software and hardware engineering work, including build-out or troubleshooting, etc. Maybe it’s all of these. No matter what, it’s a safe assumption that a big, or maybe even number one reason we all get paid is because we’re really good at the technical work.

Quiz #16 &#8211 BGP Filtering Updates

Company ABC is in process of configuring BGP Confederations between its sites. During a small transition period, there will be no BGP between R3 and R2, but instead only static routing. Have a look at the quiz and try answering the question !

The Dangers of Fanboyism

In the short amount of time since I tripped and fell into this industry, one thing is clear - fanboyism (Is that a word? It is now.) is EVERYWHERE. Those that love Cisco, really love Cisco. Those that love Juniper, really hate Cisco. It’s hard to start working in this industry, especially in a relatively single-vendor environment, and not acquire a strong affinity to one side of the other. Not to mention the fact that big companies like Cisco have huge, widely used and respected certification programs, so it’s easy for an engineer to take Cisco’s word as the word of god.

That Ole Familiar “Network” Command

A basic concept, but one that is consistently the cause of confusion even in the most learned technical circles within Cisco networking, is the specific role that the “network” command plays in various routing protocols. The reason for this confusion? The use of the word “network” itself. Let’s explain. The Problem Let’s say you had a shiny new Cisco router, and that router had 4 networks you wished to advertise (I used loopbacks for simplicity):

The Dangers of Fanboyism

In the short amount of time since I tripped and fell into this industry, one thing is clear - fanboyism (Is that a word? It is now.) is EVERYWHERE. Those that love Cisco, really love Cisco. Those that love Juniper, really hate Cisco. It’s hard to start working in this industry, especially in a relatively single-vendor environment, and not acquire a strong affinity to one side of the other. Not to mention the fact that big companies like Cisco have huge, widely used and respected certification programs, so it’s easy for an engineer to take Cisco’s word as the word of god.

That Ole Familiar “Network” Command

A basic concept, but one that is consistently the cause of confusion even in the most learned technical circles within Cisco networking, is the specific role that the “network” command plays in various routing protocols. The reason for this confusion? The use of the word “network” itself. Let’s explain. The Problem Let’s say you had a shiny new Cisco router, and that router had 4 networks you wished to advertise (I used loopbacks for simplicity):

The Importance of Effective Communication at Work

There are many different personality traits found in individuals in our industry. One trait that I’ve found dominant in technical roles is that of introversion. This trait is one that often manifests itself by creating challenges with verbal communications. Depending on an individual’s role, or desired role, this can prevent a technology rockstar from reaching […]

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Paul Stewart

Paul is a Network and Security Engineer, Trainer and Blogger who enjoys understanding how things really work. With nearly 15 years of experience in the technology industry, Paul has helped many organizations build, maintain and secure their networks and systems. Paul also writes technical content at PacketU.

The post The Importance of Effective Communication at Work appeared first on Packet Pushers Podcast and was written by Paul Stewart.

Nexus 5500 ASIC to port mapping


While assigning ports on a Cisco Nexus 5500 switch, it is a good practice to span out ports that belong to separate ASICs on board to uplink to upstream or downstream devices. For e.g. while connecting a 5500 to say a UCS FI, it is good practice to select 2 ports from one ASIC bay and 2 from another ASIC bay. The way you find out ASIC to port mapping is with the following CLI command : 'show hardware internal carmel asic <0-13>' where 0-13 are the ASIC numbers. 


Here, Ports 9-16 are mapped to ASIC 1. On Nexus 5500 switches, 8 ports are mapped to each ASIC.

HP Moonshot

Despite my humble beginnings as a network engineer, I’m almost always including servers/virtualization/storage in my day-to-day work. If you’re not into building servers from scratch (not a bad venture) then the leaders in the server space might be a good fit for you - most are doing some pretty interesting things in the battle for the top spot in this space. Most folks would agree that HP is still the number one leader, even if only considering pure volume (I see c7000 chassis EVERYWHERE).

HP Moonshot

Despite my humble beginnings as a network engineer, I’m almost always including servers/virtualization/storage in my day-to-day work. If you’re not into building servers from scratch (not a bad venture) then the leaders in the server space might be a good fit for you - most are doing some pretty interesting things in the battle for the top spot in this space. Most folks would agree that HP is still the number one leader, even if only considering pure volume (I see c7000 chassis EVERYWHERE).

Crossbow on Big F#@!ing Webtone Switch

Back in the days of SUN Microsystem, Scott McNealy asked us to build a big F#@!ing Webtone Switch. At that time, the underlying pieces weren’t there but over last few years the possibilities have opened up. We now have the switch chips from Broadcom and Intel that switch at 1.2Tbps in H/W. From a OS view, 1.2 Tbps of switching at 300ns latency is great but the more amazing thing is PCIe as a control plane which allows 20-40Gbps of control plane B/W where you can change switch registers, L2/L3-tables, TCAMs, etc at nano-second rates.

So after more than three years of work and million lines of C code, the Pluribus Network’s engineering team has the switch chip under Crossbow control. For people who are not sure what I am talking about, in 2005 project Crossbow invented virtual switching inside a server hypervisor and introduced hardware based Virtual NICs and dynamic polling to get 40Gbps of bandwidth through a server OS. The details were published in “Crossbow: From Hardware Virtualized NICs to Virtualized Networks” in ACM Sigcomm VISA 09.

In the goal to benefit from merchent silicon ecosystem and orchestrate the entire infrastructure using Open source OS Continue reading

Show 155 – Integrating OTV, FabricPath & LISP – Sponsored

At Cisco Live 2013 in Orlando, Packet Pushers co-hosts Ethan Banks and Greg Ferro sat with Nexus 7000 champion Ron Fuller and network design expert Russ White to discuss how, when and why you might choose to deploy FabricPath, OTV, or LISP. In particular, we get into the specifics of what each protocol does, where […]

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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 3M 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 155 – Integrating OTV, FabricPath & LISP – Sponsored appeared first on Packet Pushers Podcast and was written by Ethan Banks.

IGP Metric Tweaks – Direction is Important

A while back I was responsible for setting up a group of switches and routers to serve as the internet distribution for a hospital, mainly the function of designing the IGP of choice to work given the hospital’s requirements and coordinating with the teardown of the old gear. The idea was to configure EIGRP so that one next-hop was preferred over another. We know this is possible through tweaking the various metrics for a given IGP, but in the process, I was reminded of something that’s quite important to think about when doing so.

IGP Metric Tweaks – Direction is Important

A while back I was responsible for setting up a group of switches and routers to serve as the internet distribution for a hospital, mainly the function of designing the IGP of choice to work given the hospital’s requirements and coordinating with the teardown of the old gear. The idea was to configure EIGRP so that one next-hop was preferred over another. We know this is possible through tweaking the various metrics for a given IGP, but in the process, I was reminded of something that’s quite important to think about when doing so.

IGP Metric Tweaks – Direction is Important

A while back I was responsible for setting up a group of switches and routers to serve as the internet distribution for a hospital, mainly the function of designing the IGP of choice to work given the hospital’s requirements and coordinating with the teardown of the old gear. The idea was to configure EIGRP so that one next-hop was preferred over another. We know this is possible through tweaking the various metrics for a given IGP, but in the process, I was reminded of something that’s quite important to think about when doing so.

Healthy Paranoia Show 15: The Dudes of REN-ISAC

It’s the latest dudilicious episode of Healthy Paranoia! This time we’ll be covering the topic of information sharing and analysis centers (ISAC), specifically in the research and educational networking sector, aka REN-ISAC. Joining Mrs. Y on this adventure into the land of dudeness is Wes Young, REN-ISAC Principal Security Engineer and Architect (El Duderino), Keith […]

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Mrs. Y

Snarkitecht at Island of Misfit Toys

Mrs. Y is a recovering Unix engineer working in network security. Also the host of Healthy Paranoia and official nerd hunter. She likes long walks in hubsites, traveling to security conferences and spending time in the Bat Cave. Sincerely believes that every problem can be solved with a "for" loop. When not blogging or podcasting, can be found using up her 15 minutes in the Twittersphere or Google+ as @MrsYisWhy.

The post Healthy Paranoia Show 15: The Dudes of REN-ISAC appeared first on Packet Pushers Podcast and was written by Mrs. Y.

Lessons Learned Writing a Custom Config Builder

A while back, I set about developing a modest configuration templating system for my employer. When I first joined the company, new network devices were being provisioned using configuration templates stored as Microsoft Word files, which, as you can imagine, was pretty painful. Each variable had to be identified and replaced by hand in a tedious and error-prone process. I wanted something better, but also cheap (or free) and simple. So I started building something.

To kick off my crazy project, I first decided to build a web application based on the Django Python framework (the same platform on which PacketLife.net runs). Django and similar frameworks handle most of the mundane tasks involved in writing a web application and allow for rapid prototyping. It also includes a built-in administration interface for creating and manipulating data independent of the front-end user interface. I spun up a modest internal VM running...

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You got promoted, now what?

Leadership in most companies is not really something explicitly practiced. Generally, a few people who are naturally inclined kind of do their thing while the rest of the leadership ranks sort of ignore the finer points of people management. But why is that the case? And how do you avoid being one of those leaders […]

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The post You got promoted, now what? appeared first on Packet Pushers Podcast and was written by Michael Bushong.

Confusing The Familiar with The Superior

We all know the archetype of the fanboy (or fangirl of course, however I will forthwith use zealot as a gender-neutral term). They expound upon the superiority of their favorite… whatever, and lambaste the competing product or products, and will hear of nothing that would contradict their conclusions. The battle the zealots fight are well known: […]

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Tony Bourke

Tony Bourke is an IT instructor teaching Cisco and other courses for various organizations. He writes about the hilarity of the converged roles at datacenteroverlords.com and random musing on twitter @tbourke. He's also an amateur pilot, skydiver, scuba diver, marathon runner, and crazy cat lady.

The post Confusing The Familiar with The Superior appeared first on Packet Pushers Podcast and was written by Tony Bourke.