On Thu, May 7, 2020 at 2:02 AM Han Zhou <[email protected]> wrote: > Signed-off-by: Han Zhou <[email protected]> >
Acked-by: Numan Siddique <[email protected]> Thanks Numan > --- > ovn-architecture.7.xml | 50 > ++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 50 insertions(+) > > diff --git a/ovn-architecture.7.xml b/ovn-architecture.7.xml > index 3340770..1f8aa2b 100644 > --- a/ovn-architecture.7.xml > +++ b/ovn-architecture.7.xml > @@ -1733,6 +1733,56 @@ > http://docs.openvswitch.org/en/latest/topics/high-availability. > </p> > > + <h3>Restrictions of Distributed Gateway Ports</h3> > + > + <p> > + Distributed gateway ports are used to connect to an external network, > which > + can be a physical network modeled by a logical switch with a localnet > port, > + and can also be a logical switch that interconnects different OVN > + deployments (see <code>OVN Deployments Interconnection</code>). > Usually > + there can be many logical routers connected to the same external > logical > + switch, as shown in below diagram. > + </p> > + > + <pre fixed="yes"> > + +--LS-EXT-+ > + | | | > + | | | > + LR1 ... LRn > + </pre> > + > + <p> > + In this diagram, there are n logical routers connected to a logical > switch > + LS-EXT, each with a distributed gateway port, so that traffic sent to > + external world is redirected to the gateway chassis that is assigned > to the > + distributed gateway port of respective logical router. > + </p> > + > + <p> > + In the logical topology, nothing can prevent an user to add a route > between > + the logical routers via the connected distributed gateway ports on > LS-EXT. > + However, the route works only if the LS-EXT is a physical network > (modeled > + by a logical switch with a localnet port). In that case the packet > will > + be delivered between the gateway chassises through the localnet port > via > + physical network. If the LS-EXT is a regular logical switch (backed > by > + tunneling only, as in the use case of OVN interconnection), then the > packet > + will be dropped on the source gateway chassis. The limitation is due > the > + fact that distributed gateway ports are tied to physical location, and > + without physical network connection, we will end up with either > dropping > + the packet or transferring it over the tunnels which could cause > bigger > + problems such as broadcast packets being redirect repeatedly by > different > + gateway chassises. > + </p> > + > + <p> > + With the limitation in mind, if a user do want the direct connectivity > + between the logical routers, it is better to create an internal > logical > + switch connected to the logical routers with regular logical router > ports, > + which are completely distributed and the packets don't have to leave > + a chassis unless necessary, which is more optimal than routing via the > + distributed gateway ports. > + </p> > + > <h3>ARP request and ND NS packet processing</h3> > > <p> > -- > 2.1.0 > > _______________________________________________ > dev mailing list > [email protected] > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
