Latest Posts

One of my colleagues asked me if I knew what he could use to test Cisco twinax cables - specifically the SFP-H10GB-CUxM passive cables, and the SFP-H10GB-ACUxM active cables.  These cables are identified in the industry as SFP+ direct-attach copper cables, and can be used to interconnect Nexus switches and…

I am doing a 3-hour workshop on SDN at Enterprise Connect 2014 in Orlando, Florida, March 19, 2014. The session is titled “Powering Enterprise Communications with Software-Defined Networks (SDNs).” There [...]

Monitoring an SDN is going to be an interesting proposition. I wrote about the first part of monitoring and management in Monitoring a Software Defined Network, Part 1. I talk [...]

It's time to talk (briefly!) about how NSX, DFA, and ACI handle Security. This blog series has already covered ARP, L2 forwarding and L3 forwarding, complete with many technical details. I'm hoping this blog will be a bit shorter, making easier on me doing the writing and you the reader.…

I've been writing up an internal NetCraftsmen QoS template for a Cisco 3850 switch. This blog relates some lab experiences with the 3850. I hope it provides some useful information for those grappling with 3850 QoS. The second half of the blog is some observations and personal philosophy about QoS.…

In my quest to really understand SDN, I’ve been reading a number of research papers and watching presentations by industry researchers. It has been quite educational and I thought that [...]

How does L3 forwarding work in NSX, DFA, and ACI? That's the topic for this blog, blog #3 in a series. The series attempts to contrast the various behaviors of NSX, DFA, and ACI. So let's jump right in and see what's happening at Layer 3. (And if you're still…

How does L2 forwarding work in NSX, DFA, and ACI? That's the topic for this blog, blog #2 in a series. The series attempts to contrast the various behaviors of NSX, DFA, and ACI. We'll look at L2 forwarding (bridging) and some scenarios where the behavior might not be what…

Cisco is talking up the Internet of Everything (IOE) lately, with today’s focus being public sector #IOE. I’m excited about the potential, and have been watching discussions eagerly. From the news, [...]

This blog is the first in a planned series, aimed at describing how some of the current SDN offerings (NSX, DFA, and ACI) work from a practical perspective. I'll explain the title in a moment.  (Updated 1/7/14.) Concerning this blog series: I'm a networking person, so I want to know…

There's a new Cisco IWAN blog containing some good IWAN links. I'm mentioning it here in case you missed it, perhaps due to year end avoidance of online activities, busy-ness, etc. Also as followup to my prior IWAN ("Intelligent WAN") blog, IWAN, Cisco, and Akamai (Oh My!). In case you want the…

I've been trying to blog about NSX, DFA, and ACI for a while. I'll blame Cisco -- they're now coming out with additional info. And I kept coming up with more Things I Don't Know. Hence, deferred blogging, to avoid putting an ignorant foot in my mouth. I'm now equipped…