Without describing basic WLAN forwarding, OpenFlow, or SDN, I’m going to jump in and start discussing HREAP and close with questions and thoughts pertaining to protocols of choice for achieving a “controller based network.” 

For those that aren’t familiar with Cisco HREAP, it is a design for Wireless LANs in which only control traffic gets tunneled back to the controller and the data traffic stays local on the switch.  The IEEE protocol used to communicate between an AP and a controller is called CAPWAP. There are various use cases for the technology, not described here, but that is the 100,000 foot overview.

So, looking at the diagram below, we see a very basic implementation of HREAP. 

It's a little late, but this blog post was motivated after reading the following write up at GigaOm from back in March.
http://gigaom.com/2011/03/23/are-home-networks-destined-for-cloud-based-networking/#react-tabs

Taking a look at Software Defined Networking and then again at what Meraki is doing, I wonder if there are synergies behind the scenes or if there will be in the future?  Meraki is focused on simplified network device management, calling it Cloud Networking, which can even be seen as a SAAS based offering for a network management tool on steroids.  Pretty slick demo shown at the latest Wireless Tech Field Day 2.  And I do agree with Om Malik that something like this could be the future of home networking.  Partnering with Meraki, it could be a nice offering for the cable providers out there simply by adding a Meraki device and simplified management to a consumer's cable bill.

Only time will tell, but SDN could very well be the future of networking.  It will drive innovation, allow for new competition, and decrease the time to market of new features in the network.  Ideally, it will also drastically improve operational efficiencies with a suite of applications to more easily manage the network infrastructure.  Doesn’t it seem obvious by now that the hardware and software that are now so tightly integrated for every vendor should be de-coupled?

In this post, I’m going to write about possible SDN applications that I’ve been thinking about for the past few days.  It’s more thinking out loud than anything else, but I’m not talking about OpenFlow applications, but rather the next layer up, which will include the integration of applications between an OF/SDN controller and other existing or new applications located in an Enterprise Data Center. 

I was initially thinking, what existing devices are aware of the overall state of the applications, systems, and security in a data center?  What other controllers, head-end systems, and manager of manager’s are out there that could make sense to integrate with an OpenFlow controller to create a smarter network?  

Cisco IOS packaging and feature licenses have changed quite a bit over the past several years.  These changes span a variety of device platforms, so figured I’ll take two platforms/features that are commonly unknown and describe them briefly: one feature for the Catalyst 2K series switches and one licensing fact for the ISR G2 family of routers.

Inter-VLAN Routing with Catalyst 2960

A feature set of IOS came out that is called LAN BASE.  Based on the particular switch platform, this could be and is usually Layer 2 only, i.e. 3K/4K/6K, and is aimed at being used in small to medium sized organization’s access layers.  Cisco came out with this stripped down version of IOS with NO L3 (not even static routes) to compete with the HPs and DELLs of the world and has been pretty successful. 

However, what is sometimes not known is Cisco introduced Layer 3 switching on the 2960S, 2960G, 2960, and 2975 series switches when running the LAN BASE IOS with version 12.2(55)SE.  Pretty cool, right?