In the immortal words of Snoop Dogg, “Blogging Ain’t Easy.” So I took the challenge 30 days ago, and I actually completed 30 post in 30 days, but it wasn’t easy. A lot can happen in 30 days, a last minute vacation, family parties, Halloween, a network meltdown, 5-6 major CM’s, work hours that usually last until midnight, and so on…. In the end what I realized was how much of an appreciation I have for those that pump out 100-300 posts a year, most of which capture my interest and quality controlled, not a lot of filler.… Read more
Monthly Archives: November 2014
US Space Force (29 of 30)
Posted by kencelenza
on November 13, 2014
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I’m sure you are all aware of the 4 branches of the US Miltary, Army, Navy, Marines, and Space Force. Ohh wait you never heard of the USSF? Huh, that’s funny, when I joined the Air Force back in 2000, I was told that within the decade we would become the US Air and Space Force, and then US Space and Air Force, and it’s been a decade…. so what gives? I was really hoping to be apart of this:
So what does this have to do with networking?… Read more
Cisco Nexus Considerations (28 of 30)
Posted by kencelenza
on November 11, 2014
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I found some documentation that I wrote a few years ago on the Nexus product line, a few things have changed since I wrote this, but it is largely true.
Dual Homed or Active/Active Fex Design
The Nexus 7K to 2K does not support dual homed connectivity. Cisco does support this in 5K to 2K design, but not in 7K to 2K. The single homed design is the only supportable solution. This has implications that if there is a single Nexus 7K failure, it will take down all of it’s down stream FEX’s.… Read more
Build your Apps for up-time, not your network (27 of 30)
Posted by kencelenza
on November 9, 2014
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There is a paradigm shift that all of us network engineers have seen for a while now. When I started in networking, you could barely find a server that could match your LAN’s data rate (100Mb), the best services you could find were in the enterprise, and data wasn’t expected to have the same up-time as your phone system. That has obviously long since changed, and perception has with it. In the enterprise environment, your top competitors are dropbox and gmail.… Read more
Interface DNS (26 of 30)
Posted by kencelenza
on November 8, 2014
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When creating traceroutes, it is always nice to have the interfaces reflected in dns, you can see that most interfaces are seen via the internet like so:
It’s even more meaningful when you can do the same on your internal network. I created a script, which is an extension of a previous post, parses your configs from a directory you specify, creates a list of networks, and then also outputs entries to be added to your dns. You can see a quick output here:
The Case Against Information Hoarding (25 of 30)
Posted by kencelenza
on November 7, 2014
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More of a PSA then anything to let people know that information hoarding will not save your job, only cause contempt and ultimately cost you much more than you could ever gain. Let’s take two individuals of equal knowledge and work ethic working side by side, and let’s call them Bob (the information hoarder) and Bill (the opposite of Bob.)
Bob spends his days in his virtual silo, working on projects with great great success, and does what he needs to get the job done.… Read more
OUI Finder (24 of 30)
Posted by kencelenza
on November 5, 2014
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I have been looking into doing some simple scripts based on a a post on reddit, this the first one. The idea is simple, query a switch and alert if you find an oui you don’t want (e.g. netgear, linksys, etc.) I wanted to write the code a bit cleaner, but ran into a few issues, and didn’t have the time. It is functional (on cisco at least) and the alert is only set to print for now, but it is in a function and can be easily changed to do what you want with it.… Read more