Cisco ACI Initial APIC configuration

There are a lot of blog posts around about the Cisco ACI technology and design tips and tricks. If you want to know more about ACI, please read the Cisco ACI Fundamentials 

This post describes your first steps to create and installation of a ACI fabric. Our example design will look like this:

ACI network layout

Our network will exist in only one datacenter with two spine switches, two leaf switches and two  APIC controllers. The spine and leaf switches are connected with 40Gb/s, the APIC controllers are multihomed with 1Gb/s links.

Continue reading

SSH tunnel with PuTTY

Imagine, you can SSH to a host / server and use this SSH server as a proxy to access any local webserver (or anything else) on the local network of the SSH server… This is easily possible with PuTTY (awesome SSH client!).

As a demo, lets say we have the following topology:


We would like to manage the local firewall ( from a pc on the internet. We assume   that we can SSH into the SSH server.

Continue reading

SDN – A Cisco Champion’s perspective

I’ve had another opportunity to write a blog post for Cisco’s blog site: blogs.cisco.com. My second Cisco blog post is about my perspective and view about SDN, Software Defined Networking.

We’ve all heard about SDN but no one does have a real understanding about it. You can read my view on todays SDN in this blog post.

The link: SDN – A Cisco Champion’s perspective

Screen Shot 2015-04-30 at 08.47.47

Configure your multicast WAN for OTV

It is easy to find design and configuration guides about OTV implementations on Nexus 7000 switches, ASR and CSR routers. But it is much harder to find some information about the requirements for your WAN.

Please read my previous blog posts about OTV here, here, here and here. I’ll cover the OTV device configurations in those posts. But for now, lets start with the DCI WAN for OTV.

First of all, there are two OTV deployment options:

  • Unicast mode
  • Multicast mode

The WAN requirements in unicast mode are simple: deliver unicast connectivity between the join interfaces of all OTV edge devices. This is just a simple straight forward configuration, I will not cover this in this blog post.

The multicast deployment is a bit harder to configure and requirements are less easier to find. This blog post will cover the required WAN configuration in a multicast deployment. In this particular scenario, we use dark fiber / DWDM connections as DCI to get a more clear understanding about the requirements and configuration.

First, a drawing to get a view on this deployment scenario:

OTV WAN multicast  layout

OTV WAN multicast layout

This blog will provide you with the most easiest way to get your OTV multicast deployment up and running. There are some more finetune options available, but that will not be covered in this blog.

Continue reading