Hi Vinay, the openflow protocol only provides the mechanisms to instruct the switch about the different roles of the controllers.
How these roles are managed by the controllers is left out of the spefication on purpose. Different controller implementations will choose different strategies, probably depending on the specific controller application running. The assumption is that the controllers will share some state and use their communication channels to coordinate their roles and yield a safe joint control of the network. In short, it is up to the controller´s implementation. -Christian On Tue, Sep 11, 2012 at 9:53 AM, Vinay Kumar <vinaykumar1...@gmail.com> wrote: > Hello, > We are facing troubles in understanding the intricacies of open flow > networks. > 1. Our first query is regarding the various states of the controller (viz > MASTER, EQUAL, SLAVE). What are the consequences of having multiple > controllers in the equal state. Since they are allowed to modify the > switches flow table, aren't they prone to incorrectly configure the flow > table due to split brain? > 2. Our second query is regarding the election process for choosing a master. > The open flow spec mentions that the election is done by the controllers or > a 3rd party on their behalf. How do the controllers know about the other > controllers contending in the election? How is the generation_id distributed > to all active controllers after the mastership election process? > > Thanks in advance, > Vinay kumar > _______________________________________________ > openflow-discuss mailing list > openflow-discuss@lists.stanford.edu > https://mailman.stanford.edu/mailman/listinfo/openflow-discuss > -- Christian _______________________________________________ openflow-discuss mailing list openflow-discuss@lists.stanford.edu https://mailman.stanford.edu/mailman/listinfo/openflow-discuss
