On 2 November 2016 at 09:29, Ben Pfaff <b...@ovn.org> wrote:
> On Wed, Nov 02, 2016 at 09:28:44AM -0700, Ben Pfaff wrote: > > On Thu, Oct 06, 2016 at 03:53:12AM -0700, Gurucharan Shetty wrote: > > > OVN currently supports multiple gateway routers (residing on > > > different chassis) connected to the same logical topology. > > > > > > When external traffic enters the logical topology, they can enter > > > from any gateway routers and reach its eventual destination. This > > > is achieved with proper static routes configured on the gateway > > > routers. > > > > > > But when traffic is initiated in the logical space by a logical > > > port, we do not have a good way to distribute that traffic across > > > multiple gateway routers. > > > > > > This commit introduces one particular way to do it. Based on the > > > source IP address or source IP network of the packet, we can now > > > jump to a specific gateway router. > > > > > > This is very useful for a specific use case of Kubernetes. > > > When traffic is initiated inside a container heading to outside world, > > > we want to be able to send such traffic outside the gateway router > > > residing in the same host as that of the container. Since each > > > host gets a specific subnet, we can use source IP address based > > > policy routing to decide on the gateway router. > > > > > > Rationale for using the same routing table for both source and > > > destination IP address based routing: > > > > > > Some hardware network vendors support policy routing in a different > table > > > on arbitrary "match". And when a packet enters, if there is a match > > > in policy based routing table, the default routing table is not > > > consulted at all. In case of OVN, we mainly want policy based routing > > > for north-south traffic. We want east-west traffic to flow as-is. > Creating > > > a separate table for policy based routing complicates the configuration > > > quite a bit. For e.g., if we have a source IP network based rule added, > > > to decide a particular gateway router as a next hop, we should add > rules at > > > a higher priority for all the connected routes to make sure that > east-west > > > traffic is not effected in the policy based routing table itself. > > > > > > Signed-off-by: Gurucharan Shetty <g...@ovn.org> > > > > Thank you! > > > > Acked-by: Ben Pfaff <b...@ovn.org> > > Oh, you might also add a NEWS item given that OVN is no longer > experimental. > Thank you for the review. I added it to NEWS and added your suggested diff and applied. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
