| Message ID | 1588797130-76936-2-git-send-email-hzhou@ovn.org |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [ovs-dev,ovn,1/2] ovn-architecture: Update the gateway section to mention interconnection use case. | expand |
On Thu, May 7, 2020 at 2:02 AM Han Zhou <hzhou@ovn.org> wrote: > Signed-off-by: Han Zhou <hzhou@ovn.org> > Acked-by: Numan Siddique <numans@ovn.org> 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 > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > >
On Wed, May 6, 2020 at 11:10 PM Numan Siddique <numans@ovn.org> wrote: > > > > On Thu, May 7, 2020 at 2:02 AM Han Zhou <hzhou@ovn.org> wrote: >> >> Signed-off-by: Han Zhou <hzhou@ovn.org> > > > Acked-by: Numan Siddique <numans@ovn.org> > Thanks Numan. I applied this to master. > 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 >> dev@openvswitch.org >> https://mail.openvswitch.org/mailman/listinfo/ovs-dev >>
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>
Signed-off-by: Han Zhou <hzhou@ovn.org> --- ovn-architecture.7.xml | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+)