Putting OpenFlow to Work in a Production Network

Putting OpenFlow to Work in a Production

Network

Dan Schmiedt Executive Director, Network Services

and Telecommunications

Kuang-Ching “KC” Wang Associate Professor, Department of Electrical & Computer Engineering

Fan Yang, Aaron Rosen Graduate Students, Department of Electrical & Computer Engineering

The big picture from a Technology point of view …

•  OpenFlow is part of an answer to the “ossifica4on” problem we see in networking: it provides a pla=orm for innova4on and rapid deployment of new protocols in real networks.

•  OpenFlow can represent a major shiA in the way we think of and operate networks: so#ware defined, controller-‐based networking. –  Network devices can be just interface-‐containing boxes. –  Imagine, for example, how this could change the need for rou4ng protocols; the controllers already know everything!

Clemson University 2

The big picture from a University point of view…

•  OpenFlow provides a mechanism for the engagement of IT Staff with Academic faculty and students.

•  On the IT side we’re very busy and have to deal with opera4onal reali4es. Our eyes are close to the grindstone and it’s oAen hard to think “out of the box”. (We know that box very well, thank you!)

•  On the Academic side, students and faculty are eager to solve real problems and are not jaded by the reali4es of running a produc4on network.

•  So, what could happen if we combined them?


A Posi=ve Feedback Loop •  To facilitate sustained growth and leverage the power of a

University to stay crea4ve, we need a new model. –  Students

•  IT funded RAs from networking research groups

•  University funded undergraduate “Crea4ve Inquiry” team

•  Proposed Internal Internship program, supported by the Provost

–  Network engineers •  Task assignment/incen4ve model •  Internal Faculty sabba4cals


IT

Research Teaching

So, we just install the OpenFlow IOS image, give the students TACACS+ userids and let ‘em rip?

•  Ummm…: –  OF is not supported on Cisco hardware –  I’m excited about all this, but not (completely) insane

•  We support KC and his students in transpor4ng GENI OpenFlow VLANs to GENI projects from I2/NLR and around campus…

•  But, we wanted to do something with produc?on network applica4ons

•  KC and students brainstormed with network engineers to find more use cases…


OpenFlow use cases in the produc=on net •  Idea: think of ways we can leverage OpenFlow with minimal risk to the produc4on network.

•  The sky is the limit: simple python code and the NOX OpenFlow controller can tell the switch how to forward traffic in whatever ways we want…

•  Some ideas:

–  Data Analysis Network, “DAN”

–  Tracking of stolen laptops


OpenFlow use cases in the produc=on net •  Data Analysis Network, “DAN”

– We are accumula4ng a plethora of devices that need to see aggregate network traffic at arbitrary points on the network. E.g., Coradiant, MARS, FireEye, sniffers, etc. •  “You know, just have your network people send the appropriate traffic to our magical device…”

– An OpenFlow DAN would behave like a bunch of Gigamon boxes and forward traffic from SPANs or VACLs to monitoring devices.


Proposed DAN implementa=on


Some noodling on the whiteboard…

OpenFlow – A One Slide Overview


OpenFlow Controllers End Users

Network of Various Scales

Applica=on Servers

•  A soAware defined networking paradigm

•  OpenFlow-‐enabled commercial switches allow open access to their flow tables by authorized soAware OpenFlow controllers

•  Centralized, virtualized control and monitoring of network

OpenFlow use cases in the produc=on net •  Case study 1: Data Analysis Network •  Case study 2: Tracking Stolen Laptops •  Both cases are implemented with simple OpenFlow controller

(OFC) code, coexis4ng with a produc4on OFC (POFC) –  OFC coexistence made possible by FlowVisor soAware


Distribution

Core

. . .

Access

Clemson Campus Network

IT server e.g., security/app

monitor

Host 2, e.g., app server

Host 1, e.g., user desktop FlowVisor

OFC2 POFC OFC1

OpenFlow Data Analysis Network •  The problem: Packet grabbing appliances (Cisco MARS,

Coradiant, sniffers) need us to send traffic of interest to them. •  The need: a separate Data Analysis Network (DAN) to mirror

traffic from arbitrary loca4on. Like Gigamon, etc. •  The proposed solu4on: Use OF to duplicate traffic from

anywhere to designated analysis servers


User traffic Monitored traffic

OK, so how do you DO this?


When a packet comes into the controller the controller floods the packet out all ports on the switch.

Starting with a simple example, we would turn on an OF-capable switch, enable OF for a VLAN, point it at a NOX controller, and write some simple python code.

This code makes a simple hub:

Kick it up one more notch and make a learning switch…


Learn which ports the source MAC address is attached to.

Installs rule to switch to send packets to that port matching

the Destination MAC address.

Then, check if we know where the port the destination MAC address is.

…and add just a liQle more to that …


OF command #1: install rule to

duplicate packets to mirror port from

another port on the same switch

OF command #2: controller sends a

duplicate packet to mirror port, in addition to original

forwarding action

•  7 added lines of python code to default switch controller

Use case #2: OpenFlow Computer Tracking •  The problem: Large number of student laptops reported

stolen every year •  The need: In some past cases, stolen laptops remained on

campus and were accessing campus network •  The proposed solu4on: Leverage OF controller to detect and

track lost laptops’ loca4on upon network access


Reported stolen laptop FlowVisor

OFC2

Lost laptop DB

Campus switch loca=on

DB

OpenFlow controller code for computer tracker


Database query #1: check MAC

address with stolen laptop database

Database query #2: upload switch/port ID to stolen laptop database

•  Two database queries added to a standard controller template

Web Display Snapshot


Google Map Snapshot


Summary and outlook •  We believe that OpenFlow will drive a paradigm shiA in networking.

•  Universi4es can be most effec4ve when they leverage the depth of their faculty, the crea4vity of their students, and the exper4se of their staff.

•  Relax! This stuff is fun, and you’ll get smarter. •  Build a partnership with an academic part of your University.

•  Commercial support is a chicken-‐and-‐egg problem, let’s break that cycle.


FURTHER QUESTIONS CONTACT:

DAN – [email protected] KC – [email protected]


Openflow: http://openflowswitch.org GENI: http://geni.net

Putting OpenFlow to Work in a Production Network

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