geneve: T1799: add Generic Network Virtualization Encapsulation

docs/interfaces/geneve.rst

@@ -0,0 +1,52 @@
+.. _geneve-interface:
+
+######
+GENEVE
+######
+
+:abbr:`GENEVE (Generic Network Virtualization Encapsulation)` supports all of
+the capabilities of VXLAN, NVGRE, and STT and was designed to overcome their
+perceived limitations. Many believe GENEVE could eventually replace these
+earlier formats entirely.
+
+GENEVE is designed to support network virtualization use cases, where tunnels
+are typically established to act as a backplane between the virtual switches
+residing in hypervisors, physical switches, or middleboxes or other appliances.
+An arbitrary IP network can be used as an underlay although Clos networks - A
+technique for composing network fabrics larger than a single switch while
+maintaining non-blocking bandwidth across connection points. ECMP is used to
+divide traffic across the multiple links and switches that constitute the
+fabric. Sometimes termed "leaf and spine" or "fat tree" topologies.
+
+Geneve Header:
+
+.. code-block:: sh
+
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |Ver|  Opt Len  |O|C|    Rsvd.  |          Protocol Type        |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |        Virtual Network Identifier (VNI)       |    Reserved   |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |                    Variable Length Options                    |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+.. cfcmd:: set interfaces geneve gnv0 address '192.0.2.2/24'
+
+Create GENEVE tunnel listening on local address `192.0.2.2/24`.
+
+.. cfcmd:: set interfaces geneve gnv0 remote '172.18.204.10'
+
+Specify the IP address of the other end of the tunnel.
+
+.. cfcmd:: set interfaces geneve gnv0 vni '1000'
+
+:abbr:`VNI (Virtual Network Identifier)` is an identifier for a unique element
+of a virtual network.  In many situations this may represent an L2 segment,
+however, the control plane defines the forwarding semantics of decapsulated
+packets. The VNI MAY be used as part of ECMP forwarding decisions or MAY be
+used as a mechanism to distinguish between overlapping address spaces contained
+in the encapsulated packet when load balancing across CPUs.
+
+.. cfcmd:: set interfaces geneve gnv0 mtu
+
+Set interface :abbr:`MTU (Maximum Transfer Unit)` size.

docs/interfaces/index.rst

@@ -59,3 +59,4 @@ respective sections.
    vlan
    qinq
    vxlan
+   geneve