[also adding Salvatore]
On Thu, Jul 30, 2015 at 11:27:57AM -0700, Ben Pfaff wrote: > If both the router ports point to the same router, then I am not sure > why this would need to be two ports. Maybe the schema is not sufficient > to report both IPv4 and IPv6 addresses on a single router port; if so, > then I would support enhancing the schema to fix that. > > I suspect that for connecting to two different routers, it is possible > to instead connect one router and then connect that router to others in > a way that accomplishes an equivalent goal. I haven't thought it > through though. > > On Thu, Jul 30, 2015 at 09:12:14PM +0300, Gal Sagie wrote: > > Yes, i checked this on my setup. > > For example, you can have both IPv6 and IPv4 subnets per the same network > > (which maps to a logical switch) > > and connect both as two different router ports (to the same router) > > > > You can also connect the same network to two different routers, i am not > > sure if you need the extra route extension for that or not, i think you > > could > > configure it as default gateway with out this extension, but with the > > extension you > > can define routing between the two routers. > > > > > > > > > > > > On Thu, Jul 30, 2015 at 9:03 PM, Ben Pfaff <b...@nicira.com> wrote: > > > > > [adding Aaron Rosen] > > > > > > On Wed, Jul 29, 2015 at 12:20:30PM +0300, Gal Sagie wrote: > > > > Currently Neutron support defining few subnets (IP cidrs) on a network > > > > (logical switch) > > > > and connecting them to the same router (or different routers). > > > > Currently in the NB schema, the logical switch can be connected only to > > > one > > > > logical > > > > router port. > > > > > > > > This needs to be extended so a logical switch can have more then one > > > > logical router > > > > port reference to support the above use case. > > > > > > Limiting a logical switch to a single router port is an intentional > > > design decision. It means that a packet traverses at most two logical > > > switches (one at ingress, one at egress), which simplifies some of the > > > logical switch design, and it prevents loops. > > > > > > VMware's NVP controller uses the same design, for those reasons and > > > others. The NVP paper from NSDI 2014 (see > > > http://benpfaff.org/papers/net-virt.pdf) puts it this way: > > > > > > As an optimization, we constrain the logical topology such that > > > logical L2 destinations can only be present at its edge[6]. This > > > restriction means that the OVS flow table of a sending hypervisor > > > needs only to have flows for logical datapaths to which its local > > > VMs are attached as well as those of the L3 routers of the logical > > > topology; the receiving hypervisor is determined by the logical IP > > > destination address, leaving the last logical L2 hop to be executed > > > at the receiving hypervisor. > > > > > > [6] We have found little value in supporting logical routers > > > interconnected through logical switches without tenant VMs. > > > > > > Are you sure that Neutron supports multiple router ports per switch? > > > Russell Bryant (in IRC) and Aaron Rosen (in a quick in-person chat) > > > seemed doubtful. > > > > > > > > > > > -- > > Best Regards , > > > > The G. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
