One of the great things of all network virtualization solutions, is that they can be automated using some form of API that they publish. Cisco ACI is no different and offers a RESTful API which you can consume to do stuff on the network. Well, it’s a ‘sort-of’ RESTful API, as they only seem to use GET and POST functions, no DELETE, PUT, etc. Instead to delete an object, you do a POST with the status ‘deleted’. Anyway, details.


Cisco has a PowerShell … Read more

A few years ago, I created the first version of the Cisco UCS Inventory Script (UIS), a PowerShell script to read all the configuration and environment data from a UCS Manager. It can help you to get an easy overview of UCS installations after completing the initial build, or on an ongoing basis. To answer basic questions like “How many port licenses do we have left?” or “Did we create VLAN X?” – when you have no easy connectivity to the management console.

Next to reporting configuration and environment data, it also provides some basic recommendations about the configuration.

The … Read more

Cisco has just announced a new line of HyperConverged appliances called HyperFlex. With this announcement, Cisco has officially entered the HyperConverged market with an appliance with integrated compute, storage and network.

The HyperFlex line initially consists of three flavours and features the hardware of the existing Unified Computing System (UCS), coupled with a hypervisor (initially VMware vSphere, eventually Microsoft Hyper-V and KVM), a software defined storage solution from SpringPath (licensed for HyperFlex) and the networking solutions of UCS.


The three flavours of HyperFlex consists … Read more

Our earth is very slowly slowing down, which means every now and then scientists call to add an extra second to our time to compensate. The last was in 2012, the next one is coming up on June 30, 2015 23:59:60 UTC. For more information about this leap second, check

Cisco posted an impact analysis on their website with links to bug reports which determine the impact. While most campus products are unaffected, there are some warnings on datacenter products where the leap second update can lead to a crash or lockup.

My intention is not to scare, … Read more

Cisco released version 3.0(2c) (release notes here) of its UCS Infrastructure and UCS Manager software (still UCS Mini only) on the 13th of March, and it has 3 new major features: Fibre channel NPV mode, Ethernet switch mode and a HTML5 web interface for UCS Manager.

While the FC NPV and Ethernet switch modes are pretty exciting as well, they are basically just ports from regular UCS. The HTML5 web interface is an entire new feature, which eliminates the need for java. No more keeping different versions of java, activating an older version when you need to login to … Read more

In September 2014, Cisco launched the UCS Mini for what they dubbed “Edge-Scale Computing”. The UCS Mini offering is a stripped down version of the classic UCS system with Fabric Interconnects. To learn about classic UCS, click here.

In this post I will go into some details about the UCS Mini that I’ve learned over the past few months. The information here will assume you have the basic knowledge about what the UCS Mini is and what components are involved. If you need a refresher, I’ve written up a small introduction here.

Let’s dive in.

Fabric Interconnect

The … Read more

Cisco virtual Port-channels technology is a pretty straight-forward technique: make two switches seem like one switch to a downstream switch, connected with a port-channel. The downstream switch has a single port-channel going upward, which makes the switch high available and eliminating the use of spanning-tree. It looks like this:

vPC in single N7k

Read more about vPC here. For the rest of this post, I’ll assume you know how to configure and use vPC.

In a lab where you have a single Nexus 7000 switch for testing and studying, you would divide it up into VDCs for ultimate usage. OTV, Fabricpath and the … Read more