Thanks for responding. Yes, thats right. I am quoting someone's response that I received here which is the same as you have just pointed out.
"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. " Thanks again. On Thu, Aug 16, 2012 at 2:29 AM, LIANG YANG <liangy2...@gmail.com> wrote: > I'm a little confused with your question. Do you mean the mechanism > such as auto discovery of the new openflow switch ? I'm from a > openflow switch provider, and the switch has to set the controller's > ip address and then communicate with the server via tcp or other > protocol in our design. > > Thanks, > Liang > > On Wed, Aug 15, 2012 at 6:02 PM, Daniel Philip <dany1...@gmail.com> wrote: > > 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 <yangshou...@gmail.com> > 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 <dany1...@gmail.com> > 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: yangshou...@gmail.com > >> Hotmail: kimi_...@hotmail.com; kimi_...@mscampus.cn > >> > >> Personal Website: kimi4ysr.me > >> > > > > > > _______________________________________________ > > openflow-discuss mailing list > > openflow-discuss@lists.stanford.edu > > https://mailman.stanford.edu/mailman/listinfo/openflow-discuss > > >
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