Thank you all for making this clear. As part of a research project, I am trying to do "something" with mobility within an openflow network. That said, our aim is to bring-in an openflow switch into an already exiting network topology before any host is attached to this openflow switch.
That was why I was interested to know what happens and how connections are established initially when an openflow switch is detected by a controller. Thanks again. On Wed, Aug 15, 2012 at 4:05 AM, Shouren Yang <[email protected]> wrote: > Hi, Daniel, > > According to OpenFlow specification v1.0.0, the switch must eb able to > establish the communication at a user-configurable(but otherwise fixed) IP > address, using a user-specified port. > > As far as i know, you should set the controller's IP address and port when > starting OpenFlow Switch. Then the Controller and the Switch will establish > a TCP or TLS connection and OFPT_HELLO will be sent to each side of the > connection. So the controller knows there is a new Switch added into the > network. > > The controller will let the switch send LLDP packet, and if one port is > linked to another switch, the LLDP packet will be send to controller by > that switch and controller knows the topology. For details you may look > into the discovery component. > > On Wed, Aug 15, 2012 at 4:55 AM, Daniel Philip <[email protected]> wrote: > >> Hi all, >> >> By definition: When an OpenFlow switch receives a packet for the first >> time, for which it has no matching flow entries, it sends this packet to >> the controller. The controller then makes a decision on how to handle this >> packet. >> >> But, can someone please clarify how does an OpenFlow controller (say NOX) >> detect an OpenFlow switch (before it sends its first packet to the >> controller) ? >> >> Precisely, let's say there is a network that comprises of 2 openflow >> switches that are attached to NOX. Now, to this exisitng network topology, >> when a third switch moves into it, what happens ( from the controller side >> and/or switch side) unless this third switch sends its first packet to the >> controller? >> >> Thanks in advance, >> Daniel >> >> >> > > > -- > Shouren Yang 杨守仁 > Kimi > > School of Information and Communication Engineering > Beijing University of Posts and Telecommunications > 北京邮电大学 信息与通信工程学院 > > Mobile Phone: > (86) 1861-078-2697 Beijing > (86) 1506-781-8982 WenZhou > > Gmail: [email protected] > Hotmail: [email protected]; [email protected] > > Personal Website: kimi4ysr.me > >
