I recently completed the Programming for Network Engineers course from the Cisco Learning Network (CLN) and I must say I was really impressed. I’ve mentioned similar courses in the past but I was really impressed with this particular one for multiple different reasons:
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.
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).
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.
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”
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.
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! :p
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.