----- Original Message ----- > Comments in-line. > > ----- Original Message ----- > > On 23 May 2015 at 04:43, Assaf Muller < amul...@redhat.com > wrote: > > > > > > > > There's no real reason as far as I'm aware, just an implementation > > decision. > > > > This is inaccurate. There is a reason(s), and this has been asked before: > > > > http://lists.openstack.org/pipermail/openstack/2014-March/005950.html > > This link is to a thread asking why do we connect a Linux bridge between a > tap > device and br-int (For security groups). > > > http://lists.openstack.org/pipermail/openstack/2014-April/006865.html > > This link is to this thread itself.
No it's from another author but just the same text (almost exactly). i.e. https://www.diffchecker.com/xl98zm9a Either it's the same poster or some freak coincidence, or just some copy paste.. Also Vivek gave the correct answer on that thread: http://lists.openstack.org/pipermail/openstack/2014-April/006868.html In a nutshell, decoupling the overlay layer from the VM connectivity. VMs are always connected to the br-int the same way, but the overlay (vxlan/gre or vlans) is connected differently. > > > > > In a nutshell, the design decision that led to the existing architecture is > > due to the way OVS handles packets and interact with netfilter. > > I think you're talking about the bridge between a tap device and br-int and > not about br-tun. > > > > > The fact that we keep asking the same question clearly shows lack of > > documentation, both developer and user facing. > > > > I'll get this fixed once and for all. > > Thank you. > > > > > Thanks, > > Armando > > > > > > > > > > > > > > On 21 במאי 2015, at 01:48, Na Zhu < na...@cn.ibm.com > wrote: > > > > > > > > > > > > > > Dear, > > > > > > When OVS plugin is used with GRE option in Neutron, I see that each compute > > node has br-tun and br-int bridges created. > > > > I'm trying to understand why we need the additional br-tun bridge here. > > Can't we create tunneling ports in br-int bridge, and have br-int relay > > traffic between VM ports and tunneling ports directly? Why do we have to > > introduce another br-tun bridge? > > > > > > Regards, > > Juno Zhu > > Staff Software Engineer, System Networking > > China Systems and Technology Lab (CSTL), IBM Wuxi > > Email: na...@cn.ibm.com > > > > > > > > __________________________________________________________________________ > > OpenStack Development Mailing List (not for usage questions) > > Unsubscribe: openstack-dev-requ...@lists.openstack.org ?subject:unsubscribe > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > __________________________________________________________________________ > > OpenStack Development Mailing List (not for usage questions) > > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > > > > > __________________________________________________________________________ > > OpenStack Development Mailing List (not for usage questions) > > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev