docs: networking: convert vxlan.txt to ReST

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 60 insertions, 0 deletions

diff --git a/Documentation/networking/vxlan.rst b/Documentation/networking/vxlan.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+======================================================
+Virtual eXtensible Local Area Networking documentation
+======================================================
+
+The VXLAN protocol is a tunnelling protocol designed to solve the
+problem of limited VLAN IDs (4096) in IEEE 802.1q.  With VXLAN the
+size of the identifier is expanded to 24 bits (16777216).
+
+VXLAN is described by IETF RFC 7348, and has been implemented by a
+number of vendors.  The protocol runs over UDP using a single
+destination port.  This document describes the Linux kernel tunnel
+device, there is also a separate implementation of VXLAN for
+Openvswitch.
+
+Unlike most tunnels, a VXLAN is a 1 to N network, not just point to
+point. A VXLAN device can learn the IP address of the other endpoint
+either dynamically in a manner similar to a learning bridge, or make
+use of statically-configured forwarding entries.
+
+The management of vxlan is done in a manner similar to its two closest
+neighbors GRE and VLAN. Configuring VXLAN requires the version of
+iproute2 that matches the kernel release where VXLAN was first merged
+upstream.
+
+1. Create vxlan device::
+
+    # ip link add vxlan0 type vxlan id 42 group 239.1.1.1 dev eth1 dstport 4789
+
+This creates a new device named vxlan0.  The device uses the multicast
+group 239.1.1.1 over eth1 to handle traffic for which there is no
+entry in the forwarding table.  The destination port number is set to
+the IANA-assigned value of 4789.  The Linux implementation of VXLAN
+pre-dates the IANA's selection of a standard destination port number
+and uses the Linux-selected value by default to maintain backwards
+compatibility.
+
+2. Delete vxlan device::
+
+    # ip link delete vxlan0
+
+3. Show vxlan info::
+
+    # ip -d link show vxlan0
+
+It is possible to create, destroy and display the vxlan
+forwarding table using the new bridge command.
+
+1. Create forwarding table entry::
+
+    # bridge fdb add to 00:17:42:8a:b4:05 dst 192.19.0.2 dev vxlan0
+
+2. Delete forwarding table entry::
+
+    # bridge fdb delete 00:17:42:8a:b4:05 dev vxlan0
+
+3. Show forwarding table::
+
+    # bridge fdb show dev vxlan0