I get the communication trough switches to switches in double way.. Thank you for all.
On Thu, Oct 20, 2011 at 12:59, scolfield <kscolfi...@gmail.com> wrote: > Hi, > > I imagined that the steps were like you mentioned... well, > > Firstly, s3 send packet_in to c0, and another moment s2 send packet_in > tos3that send to > c0... > Well, as you mentioned earlier, I need to set initial flow entries, that > is, I think that is the flow from s2 to s3 > ,.. one time initiated the topology, like the linear topology, the > initial flow entries should be installed, I think.. > so that initial flow entries must be configured in the topology script? > or maybe from CLI via dpctl? > > thank you, > > > On Thu, Oct 20, 2011 at 11:31, Kyriakos Zarifis <kyr.zari...@gmail.com>wrote: > >> Yes, that is possible. This is where in-band vs out-of-band control comes >> to play: If the physical topology looks exactly like what you described then >> control of sw1 can only been done in-band (meaning, the control packets are >> using the same links as the data packets). In order for that to be possible, >> there need to be some initial flow entries in the intermediate switches to >> allow a remote switch to connect to the controller. I don't think there is a >> standardized way to set up in-band control, but I am guessing a simple >> version would be something like: >> >> - s3 connects to c0 > > - the controller receives packet_in from s3, which originated in s2 while >> it tried to connect >> > - c0 sets a flow on s3 that allows traffic from s2 to reach it >> > - at this point s2 and s3 are connected to the controller >> - sw2 picks up packet from s1 and sends packet_in to c0 >> >> OpenvSwitch has a pretty sophisticated approach to in-band control. If >> you're interested you can take a look here : >> >> http://openvswitch.org/cgi-bin/gitweb.cgi?p=openvswitch;a=blob_plain;f=DESIGN >> (look for "in-band") >> >> On Thu, Oct 20, 2011 at 5:39 AM, scolfield <kscolfi...@gmail.com> wrote: >> >>> Hi, >>> >>> Thanks for your reply. >>> It's possible openflow messages across several switches until achieve the >>> controller? >>> Such as host -> sw1 -> sw2 -> sw3 -> c0 or in a reverse way in linear >>> topology? >>> Consider that the host packet need to achieve a server connected to sw3and >>> there are only >>> one controller linked to one switch. >>> >>> -- >>> scolf >>> >>> >>> On Thu, Oct 20, 2011 at 06:32, Kyriakos Zarifis >>> <kyr.zari...@gmail.com>wrote: >>> >>>> Hi, >>>> >>>> pyswitch itself is really not aware of any topology. It only stores >>>> state that is relevant to switches separately (i.e. it stores a mapping of >>>> mac addresses to local ports for a switch). >>>> >>>> Now, whether a control packet (like a packet_in) will reach the >>>> controller if it's not directly physically connected to it is another >>>> issue, >>>> and is irrelevant to what NOX application (eg pyswitch) is running. >>>> Switches >>>> are connected to the controller through a separate control channel, so as >>>> long as this channel has been established (which is when the switch first >>>> connects to NOX), then the packet_ins will find their way to NOX through >>>> that (irrespective of dataplane connectivity, which is established by NOX >>>> applications) >>>> >>>> (another thing to consider is whether the switch-controller connection >>>> is in-bound/out-of-bound) >>>> >>>> Does this make sense? >>>> >>>> On Wed, Oct 19, 2011 at 5:20 PM, scolfield <kscolfi...@gmail.com>wrote: >>>> >>>>> Hi, >>>>> >>>>> The pyswitch example can learn topology of networks? Such as a >>>>> corporation architecture when >>>>> there are hierarchical switches interconnected one to another creating >>>>> several "layers" of switches, >>>>> at this case, the one openflow controller connected to two distinct >>>>> switches, can learn which ports >>>>> to send a ping packets, for example? The packet in messages will be >>>>> forwarded automatically through >>>>> switches until reach a controller? >>>>> >>>>> -- >>>>> scolfield >>>>> >>>>> _______________________________________________ >>>>> nox-dev mailing list >>>>> nox-dev@noxrepo.org >>>>> http://noxrepo.org/mailman/listinfo/nox-dev >>>>> >>>>> >>>> >>> >> >
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