Thank you very much! That’s all I need to know. > On Apr 23, 2016, at 2:07 PM, Ben Pfaff <b...@ovn.org> wrote: > > On Sat, Apr 23, 2016 at 11:45:12AM -0700, Ben Warren wrote: >> Thanks for the explanations! >>> On Apr 23, 2016, at 10:15 AM, Ben Pfaff <b...@ovn.org> wrote: >>> >>> On Fri, Apr 22, 2016 at 11:25:26PM -0700, Ben Warren wrote: >>>> As you can see, the disconnects happen when the datapath ID changes, >>>> presumably due to adding interfaces? Only the addition of the first >>>> two interfaces seem to bring it down. >>> >>> OVS disconnects OpenFlow connections when the datapath ID changes >>> because the datapath ID is important to some controllers and OpenFlow >>> provides no way for a switch to notify a controller that the datapath ID >>> has changed. >>> >> OK, so what causes the datapath ID to change (Linux kernel 3.10 >> datapath in this case)? Does it come from the kernel or is it an OVS >> thing? > > The datapath ID is an OpenFlow concept, and there's no connection to the > OVS concept of a "datapath", so the datapath in use doesn't matter. > > By default, Open vSwitch uses the lowest-numbered Ethernet address of > any of the physical ports connected to a bridge as the bridge's datapath > ID. You can override this with other-config:datapath-id, as documented, > but otherwise if the ports in the bridge change the datapath ID may > change as well. > >>>> On the client side, I’m really confused. As you can see, I re-open >>>> the connection with a HELLO message, and the HELLO response comes back >>>> with an earlier XID (0x80 vs. the expected 0x86). Message 0x83 was a >>>> BARRIER response, and a valid BARRIER reply was received, so it would >>>> seem that messages after 0x80 were accepted: >>> >>> HELLO is not a request/response message. Rather, both sides of the >>> OpenFlow connection send a hello message at the initiation of the >>> connection. Each side chooses its own xid as it wishes, so one cannot >>> expect the xids to match. The xid for a hello message is only >>> significant for sending an OFPT_ERROR response, if necessary. >> >> OK, is this understanding correct: for send/receive (GetConfig, >> Feature etc.) messages ovs-vswitchd will mirror back the XID of the >> request, > > OpenFlow requires that behavior. > >> but for HELLO it keeps a static monotonically increasing counter? > > That's the current implementation but there's certainly no guarantee > that it won't change.
smime.p7s
Description: S/MIME cryptographic signature
_______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
