Great quality and FREE ACI Training!

I just came across this great quality AND FREE Cisco ACI Training by LumosCloud!


Just about 15 months ago, I paid good money for the first version of their training. This newer version, available for free at the link above, seems to be just as great in quality and super comprehensive too.

Of course, Cisco has some pretty great ACI labs also available for free on dCloud (which I have mentioned a couple of times before). With the above combination, you can learn Cisco ACI in pretty great depth.

I am still trying to figure out what the catch is with the Lumos’s free training. Until then, enjoy! ūüėČ

Packet capture on NX-OS

NX-OS has had the great Ethanalyzer feature since very early versions. It allows you to perform limited packet captures directly on your NX-OS based switch!


It is however a pain to use practically and has lots of limitations. One of the biggest limitations is that it can only capture traffic hitting the CPU – so you are limited to control plane and management plane traffic only. That however is key to solving many problems that are often associated with (or blamed on) the network.

Here is an example that captures, displays and filters ARP packets processed through the switch these commands are being performed on.

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Reach out for career advice!

I’ve been blessed with a great career in IT. I’ve had the honor of mentoring numerous individuals with their careers in IT – and one thing that I see happening consistently is that the ones that are typically the MOST qualified are the LEAST HESITANT in asking for help. Many people whom I’ve mentored have advanced degrees and certifications – like MSc, CCIE, even Phd., and other certifications, who are far more qualified than I am – and they are the ones reaching out for guidance!
What I’ve learned from this is that those are not afraid of asking for help, and don’t let their ego or nervousness or hesitation or riskiness or whatever else may be holding them back get in the way, end up being most successful.

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Simple Multicast Testing Tool for Windows

After multicast has been configured on the network, one of the biggest challenges tends to involve actually testing multicast functionality in between two Windows machines (physical or VMs) connected via the network.

In the past, I’ve just used iPerf and/or multicast video streaming via VLC, which are still valid and great testing options, but, sometimes when using these tools, I’m often second guessing my self as to whether or not I am even using the tool correctly and legitimately generating the multicast stream that I intend to generate. Part of the problem is that iPerf can be complicated to use, and VLC multicast streaming can be buggy.

Singlewire Multicast Testing Tool

I would still continue to use the iPerf/jPerf and VLC multicast video streaming method, which can be a good way to test throughput, however, I’ve now come across new VERY SIMPLE tool to validate basic multicast connectivity, the Singlewire Mutlicast Testing Tool (free).

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Best resources for learning Cisco ACI

Update March 2019: The below blog is now fairly outdated. For my latest recommendation, please see this post

Update Oct 31, 2016: Added Jason Lunde’s “Learning Cisco ACI” course at twistedIT

For those who’ve read previous blog posts, you can probably tell that constant learning and training is a recurring theme on my blog. I even have one blog posts dedicated to “learning to learn”.¬†Continuing on with that tradition, this post will be dedicated to getting you up to speed with Cisco ACI.


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Microsoft Message Analyzer – MS’s poorly named Wireshark sidekick

Have you ever heard of Microsoft Message Analyzer? While troubleshooting some networking issues with Windows Server 2012, I requested the application owner to install Wireshark. Being a good systems admin, the application owner was naturally suspicious of an application with ‘shark’ in it’s name. Despite my insistence, I wasn’t able to convince the administrator to install Wireshark. We decided to look at alternatives – and came across Microsoft’s own Windows Message Analyzer! (WMA).


It turns out, WMA is very similar in form factor to Wireshark, Continue reading “Microsoft Message Analyzer – MS’s poorly named Wireshark sidekick”

SPAN and Nexus / ACI platform caveats and limitations

First of all, there is no way I can make a complete, comprehensive list of caveats and limitations on all the different Nexus platforms and with all the different major revisions, modules and linecards. My aim is to capture some of the major gotchas and meaty details specific to each platform. For detailed guidelines and limitations, please see references end of end of the blog.


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Million dollar monitoring solutions vs Solarwinds

TL;DR summary: Before finalizing on a million-dollar network monitoring solution, be sure to consider and trial at least a few smaller vendors, new comers and open-source solutions. You may be surprised at their breadth, capability and value. And no, Solarwinds did not pay me to write this blog post! ūüėČ

10+ years ago, Solarwinds had a bad reputation for not scaling, being slow, buggy, etc. In the last 7-8 years, it has really transformed, and is a different company, with product portfolio that offers amazing value on several fronts.

Having worked very¬†closely with CA Spectrum/eHealth, Riverbed/OPNet SteelCentral, Nimsoft (purchased by CA), IBM Tivoli ITNM, HP BTO/OpenView, Cacti (open source), Observium/Libre NMS (open source), Zenoss (open source), WhatsUpGold, InterMapper, Cisco DCNM, Cisco Prime/Works¬†and Solarwinds in the last decade, I continue to stay impressed with the usability, feature-set, price-point and scalability offered by Solarwinds products compared to it’s competitors.


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