</li>
</ol>
- <h2>Life Cycle of a Packet</h2>
+ <h2>Architectural Physical Life Cycle of a Packet</h2>
<p>
This section describes how a packet travels from one virtual machine or
<dt>logical input port field</dt>
<dd>
- A field that denotes the logical port from which the packet
- entered the logical datapath.
- <!-- Keep the following in sync with MFF_LOG_INPORT in
- ovn/controller/lflow.h. -->
- OVN stores this in Nicira extension register number 6. (This field is
- passed across tunnels as part of the tunnel key.)
+ <p>
+ A field that denotes the logical port from which the packet
+ entered the logical datapath.
+ <!-- Keep the following in sync with MFF_LOG_INPORT in
+ ovn/controller/lflow.h. -->
+ OVN stores this in Nicira extension register number 6.
+ </p>
+
+ <p>
+ Geneve and STT tunnels pass this field as part of the tunnel key.
+ Although VXLAN tunnels do not explicitly carry a logical input port,
+ OVN only uses VXLAN to communicate with gateways that from OVN's
+ perspective consist of only a single logical port, so that OVN can set
+ the logical input port field to this one on ingress to the OVN logical
+ pipeline.
+ </p>
</dd>
<dt>logical output port field</dt>
<dd>
- A field that denotes the logical port from which the packet will
- leave the logical datapath. This is initialized to 0 at the
- beginning of the logical ingress pipeline.
- <!-- Keep the following in sync with MFF_LOG_OUTPORT in
- ovn/controller/lflow.h. -->
- OVN stores this in
- Nicira extension register number 7. (This field is passed across
- tunnels as part of the tunnel key.)
+ <p>
+ A field that denotes the logical port from which the packet will
+ leave the logical datapath. This is initialized to 0 at the
+ beginning of the logical ingress pipeline.
+ <!-- Keep the following in sync with MFF_LOG_OUTPORT in
+ ovn/controller/lflow.h. -->
+ OVN stores this in Nicira extension register number 7.
+ </p>
+
+ <p>
+ Geneve and STT tunnels pass this field as part of the tunnel key.
+ VXLAN tunnels do not transmit the logical output port field.
+ </p>
+ </dd>
+
+ <dt>conntrack zone field</dt>
+ <dd>
+ A field that denotes the connection tracking zone. The value only
+ has local significance and is not meaningful between chassis.
+ This is initialized to 0 at the beginning of the logical ingress
+ pipeline. OVN stores this in Nicira extension register number 5.
</dd>
<dt>VLAN ID</dt>
<p>
Flows in table 33 resemble those in table 32 but for logical ports that
- reside locally rather than remotely. For unicast logical output ports
+ reside locally rather than remotely. (This includes logical patch
+ ports, which do not have a physical location and effectively reside on
+ every hypervisor.) For unicast logical output ports
on the local hypervisor, the actions just resubmit to table 34. For
multicast output ports that include one or more logical ports on the
local hypervisor, for each such logical port <var>P</var>, the actions
is a container nested with a VM, then before sending the packet the
actions push on a VLAN header with an appropriate VLAN ID.
</p>
+
+ <p>
+ If the logical egress port is a logical patch port, then table 64
+ outputs to an OVS patch port that represents the logical patch port.
+ The packet re-enters the OpenFlow flow table from the OVS patch port's
+ peer in table 0, which identifies the logical datapath and logical
+ input port based on the OVS patch port's OpenFlow port number.
+ </p>
+ </li>
+ </ol>
+
+ <h2>Life Cycle of a VTEP gateway</h2>
+
+ <p>
+ A gateway is a chassis that forwards traffic between the OVN-managed
+ part of a logical network and a physical VLAN, extending a
+ tunnel-based logical network into a physical network.
+ </p>
+
+ <p>
+ The steps below refer often to details of the OVN and VTEP database
+ schemas. Please see <code>ovn-sb</code>(5), <code>ovn-nb</code>(5)
+ and <code>vtep</code>(5), respectively, for the full story on these
+ databases.
+ </p>
+
+ <ol>
+ <li>
+ A VTEP gateway's life cycle begins with the administrator registering
+ the VTEP gateway as a <code>Physical_Switch</code> table entry in the
+ <code>VTEP</code> database. The <code>ovn-controller-vtep</code>
+ connected to this VTEP database, will recognize the new VTEP gateway
+ and create a new <code>Chassis</code> table entry for it in the
+ <code>OVN_Southbound</code> database.
+ </li>
+
+ <li>
+ The administrator can then create a new <code>Logical_Switch</code>
+ table entry, and bind a particular vlan on a VTEP gateway's port to
+ any VTEP logical switch. Once a VTEP logical switch is bound to
+ a VTEP gateway, the <code>ovn-controller-vtep</code> will detect
+ it and add its name to the <var>vtep_logical_switches</var>
+ column of the <code>Chassis</code> table in the <code>
+ OVN_Southbound</code> database. Note, the <var>tunnel_key</var>
+ column of VTEP logical switch is not filled at creation. The
+ <code>ovn-controller-vtep</code> will set the column when the
+ correponding vtep logical switch is bound to an OVN logical network.
+ </li>
+
+ <li>
+ Now, the administrator can use the CMS to add a VTEP logical switch
+ to the OVN logical network. To do that, the CMS must first create a
+ new <code>Logical_Port</code> table entry in the <code>
+ OVN_Northbound</code> database. Then, the <var>type</var> column
+ of this entry must be set to "vtep". Next, the <var>
+ vtep-logical-switch</var> and <var>vtep-physical-switch</var> keys
+ in the <var>options</var> column must also be specified, since
+ multiple VTEP gateways can attach to the same VTEP logical switch.
+ </li>
+
+ <li>
+ The newly created logical port in the <code>OVN_Northbound</code>
+ database and its configuration will be passed down to the <code>
+ OVN_Southbound</code> database as a new <code>Port_Binding</code>
+ table entry. The <code>ovn-controller-vtep</code> will recognize the
+ change and bind the logical port to the corresponding VTEP gateway
+ chassis. Configuration of binding the same VTEP logical switch to
+ a different OVN logical networks is not allowed and a warning will be
+ generated in the log.
+ </li>
+
+ <li>
+ Beside binding to the VTEP gateway chassis, the <code>
+ ovn-controller-vtep</code> will update the <var>tunnel_key</var>
+ column of the VTEP logical switch to the corresponding <code>
+ Datapath_Binding</code> table entry's <var>tunnel_key</var> for the
+ bound OVN logical network.
+ </li>
+
+ <li>
+ Next, the <code>ovn-controller-vtep</code> will keep reacting to the
+ configuration change in the <code>Port_Binding</code> in the
+ <code>OVN_Northbound</code> database, and updating the
+ <code>Ucast_Macs_Remote</code> table in the <code>VTEP</code> database.
+ This allows the VTEP gateway to understand where to forward the unicast
+ traffic coming from the extended external network.
+ </li>
+
+ <li>
+ Eventually, the VTEP gateway's life cycle ends when the administrator
+ unregisters the VTEP gateway from the <code>VTEP</code> database.
+ The <code>ovn-controller-vtep</code> will recognize the event and
+ remove all related configurations (<code>Chassis</code> table entry
+ and port bindings) in the <code>OVN_Southbound</code> database.
+ </li>
+
+ <li>
+ When the <code>ovn-controller-vtep</code> is terminated, all related
+ configurations in the <code>OVN_Southbound</code> database and
+ the <code>VTEP</code> database will be cleaned, including
+ <code>Chassis</code> table entries for all registered VTEP gateways
+ and their port bindings, and all <code>Ucast_Macs_Remote</code> table
+ entries and the <code>Logical_Switch</code> tunnel keys.
</li>
</ol>
projects / cascardo / ovs.git / blobdiff