--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================================
+DSA switch configuration from userspace
+=======================================
+
+The DSA switch configuration is not integrated into the main userspace
+network configuration suites by now and has to be performed manualy.
+
+.. _dsa-config-showcases:
+
+Configuration showcases
+-----------------------
+
+To configure a DSA switch a couple of commands need to be executed. In this
+documentation some common configuration scenarios are handled as showcases:
+
+*single port*
+ Every switch port acts as a different configurable Ethernet port
+
+*bridge*
+ Every switch port is part of one configurable Ethernet bridge
+
+*gateway*
+ Every switch port except one upstream port is part of a configurable
+ Ethernet bridge.
+ The upstream port acts as different configurable Ethernet port.
+
+All configurations are performed with tools from iproute2, which is available
+at https://www.kernel.org/pub/linux/utils/net/iproute2/
+
+Through DSA every port of a switch is handled like a normal linux Ethernet
+interface. The CPU port is the switch port connected to an Ethernet MAC chip.
+The corresponding linux Ethernet interface is called the master interface.
+All other corresponding linux interfaces are called slave interfaces.
+
+The slave interfaces depend on the master interface. They can only brought up,
+when the master interface is up.
+
+In this documentation the following Ethernet interfaces are used:
+
+*eth0*
+ the master interface
+
+*lan1*
+ a slave interface
+
+*lan2*
+ another slave interface
+
+*lan3*
+ a third slave interface
+
+*wan*
+ A slave interface dedicated for upstream traffic
+
+Further Ethernet interfaces can be configured similar.
+The configured IPs and networks are:
+
+*single port*
+ * lan1: 192.0.2.1/30 (192.0.2.0 - 192.0.2.3)
+ * lan2: 192.0.2.5/30 (192.0.2.4 - 192.0.2.7)
+ * lan3: 192.0.2.9/30 (192.0.2.8 - 192.0.2.11)
+
+*bridge*
+ * br0: 192.0.2.129/25 (192.0.2.128 - 192.0.2.255)
+
+*gateway*
+ * br0: 192.0.2.129/25 (192.0.2.128 - 192.0.2.255)
+ * wan: 192.0.2.1/30 (192.0.2.0 - 192.0.2.3)
+
+.. _dsa-tagged-configuration:
+
+Configuration with tagging support
+----------------------------------
+
+The tagging based configuration is desired and supported by the majority of
+DSA switches. These switches are capable to tag incoming and outgoing traffic
+without using a VLAN based configuration.
+
+single port
+~~~~~~~~~~~
+
+.. code-block:: sh
+
+ # configure each interface
+ ip addr add 192.0.2.1/30 dev lan1
+ ip addr add 192.0.2.5/30 dev lan2
+ ip addr add 192.0.2.9/30 dev lan3
+
+ # The master interface needs to be brought up before the slave ports.
+ ip link set eth0 up
+
+ # bring up the slave interfaces
+ ip link set lan1 up
+ ip link set lan2 up
+ ip link set lan3 up
+
+bridge
+~~~~~~
+
+.. code-block:: sh
+
+ # The master interface needs to be brought up before the slave ports.
+ ip link set eth0 up
+
+ # bring up the slave interfaces
+ ip link set lan1 up
+ ip link set lan2 up
+ ip link set lan3 up
+
+ # create bridge
+ ip link add name br0 type bridge
+
+ # add ports to bridge
+ ip link set dev lan1 master br0
+ ip link set dev lan2 master br0
+ ip link set dev lan3 master br0
+
+ # configure the bridge
+ ip addr add 192.0.2.129/25 dev br0
+
+ # bring up the bridge
+ ip link set dev br0 up
+
+gateway
+~~~~~~~
+
+.. code-block:: sh
+
+ # The master interface needs to be brought up before the slave ports.
+ ip link set eth0 up
+
+ # bring up the slave interfaces
+ ip link set wan up
+ ip link set lan1 up
+ ip link set lan2 up
+
+ # configure the upstream port
+ ip addr add 192.0.2.1/30 dev wan
+
+ # create bridge
+ ip link add name br0 type bridge
+
+ # add ports to bridge
+ ip link set dev lan1 master br0
+ ip link set dev lan2 master br0
+
+ # configure the bridge
+ ip addr add 192.0.2.129/25 dev br0
+
+ # bring up the bridge
+ ip link set dev br0 up
+
+.. _dsa-vlan-configuration:
+
+Configuration without tagging support
+-------------------------------------
+
+A minority of switches are not capable to use a taging protocol
+(DSA_TAG_PROTO_NONE). These switches can be configured by a VLAN based
+configuration.
+
+single port
+~~~~~~~~~~~
+The configuration can only be set up via VLAN tagging and bridge setup.
+
+.. code-block:: sh
+
+ # tag traffic on CPU port
+ ip link add link eth0 name eth0.1 type vlan id 1
+ ip link add link eth0 name eth0.2 type vlan id 2
+ ip link add link eth0 name eth0.3 type vlan id 3
+
+ # The master interface needs to be brought up before the slave ports.
+ ip link set eth0 up
+ ip link set eth0.1 up
+ ip link set eth0.2 up
+ ip link set eth0.3 up
+
+ # bring up the slave interfaces
+ ip link set lan1 up
+ ip link set lan1 up
+ ip link set lan3 up
+
+ # create bridge
+ ip link add name br0 type bridge
+
+ # activate VLAN filtering
+ ip link set dev br0 type bridge vlan_filtering 1
+
+ # add ports to bridges
+ ip link set dev lan1 master br0
+ ip link set dev lan2 master br0
+ ip link set dev lan3 master br0
+
+ # tag traffic on ports
+ bridge vlan add dev lan1 vid 1 pvid untagged
+ bridge vlan add dev lan2 vid 2 pvid untagged
+ bridge vlan add dev lan3 vid 3 pvid untagged
+
+ # configure the VLANs
+ ip addr add 192.0.2.1/30 dev eth0.1
+ ip addr add 192.0.2.5/30 dev eth0.2
+ ip addr add 192.0.2.9/30 dev eth0.3
+
+ # bring up the bridge devices
+ ip link set br0 up
+
+
+bridge
+~~~~~~
+
+.. code-block:: sh
+
+ # tag traffic on CPU port
+ ip link add link eth0 name eth0.1 type vlan id 1
+
+ # The master interface needs to be brought up before the slave ports.
+ ip link set eth0 up
+ ip link set eth0.1 up
+
+ # bring up the slave interfaces
+ ip link set lan1 up
+ ip link set lan2 up
+ ip link set lan3 up
+
+ # create bridge
+ ip link add name br0 type bridge
+
+ # activate VLAN filtering
+ ip link set dev br0 type bridge vlan_filtering 1
+
+ # add ports to bridge
+ ip link set dev lan1 master br0
+ ip link set dev lan2 master br0
+ ip link set dev lan3 master br0
+ ip link set eth0.1 master br0
+
+ # tag traffic on ports
+ bridge vlan add dev lan1 vid 1 pvid untagged
+ bridge vlan add dev lan2 vid 1 pvid untagged
+ bridge vlan add dev lan3 vid 1 pvid untagged
+
+ # configure the bridge
+ ip addr add 192.0.2.129/25 dev br0
+
+ # bring up the bridge
+ ip link set dev br0 up
+
+gateway
+~~~~~~~
+
+.. code-block:: sh
+
+ # tag traffic on CPU port
+ ip link add link eth0 name eth0.1 type vlan id 1
+ ip link add link eth0 name eth0.2 type vlan id 2
+
+ # The master interface needs to be brought up before the slave ports.
+ ip link set eth0 up
+ ip link set eth0.1 up
+ ip link set eth0.2 up
+
+ # bring up the slave interfaces
+ ip link set wan up
+ ip link set lan1 up
+ ip link set lan2 up
+
+ # create bridge
+ ip link add name br0 type bridge
+
+ # activate VLAN filtering
+ ip link set dev br0 type bridge vlan_filtering 1
+
+ # add ports to bridges
+ ip link set dev wan master br0
+ ip link set eth0.1 master br0
+ ip link set dev lan1 master br0
+ ip link set dev lan2 master br0
+
+ # tag traffic on ports
+ bridge vlan add dev lan1 vid 1 pvid untagged
+ bridge vlan add dev lan2 vid 1 pvid untagged
+ bridge vlan add dev wan vid 2 pvid untagged
+
+ # configure the VLANs
+ ip addr add 192.0.2.1/30 dev eth0.2
+ ip addr add 192.0.2.129/25 dev br0
+
+ # bring up the bridge devices
+ ip link set br0 up