networking/dsa/configuration.rst

4 DSA switch configuration from userspace
7 The DSA switch configuration is not integrated into the main userspace
15 To configure a DSA switch a couple of commands need to be executed. In this
32 Through DSA every port of a switch is handled like a normal linux Ethernet
42 - when a DSA slave interface is brought up, the master interface is
44 - when the master interface is brought down, all DSA slave interfaces are
88 DSA switches. These switches are capable to tag incoming and outgoing traffic
302 The existing DSA switches do not have the necessary hardware support to keep
308 Up until kernel v4.14, DSA only supported user space management of bridge FDB
319 Due to a bug, the bridge bypass FDB implementation provided by DSA did not
323 explicit) are treated by DSA as ``static`` even if they are ``local``.
329     # behaves the same for DSA as this command:
336 DSA switch using the bridge bypass operations, and works by mistake. Other
338 such, will not forward it, as opposed to DSA.
340 Between kernel v4.14 and v5.14, DSA has supported in parallel two modes of
349 Since kernel v5.14, DSA has gained stronger integration with the bridge's
365 flags when working with bridge FDB entries on DSA switch interfaces.
370 Typically, DSA switches are attached to the host via a single Ethernet
375 DSA can make use of multiple CPU ports in two ways. First, it is possible to
383 This can be achieved by placing the DSA masters under a LAG interface (bonding
384 or team). DSA monitors this operation and creates a mirror of this software LAG
385 on the CPU ports facing the physical DSA masters that constitute the LAG slave
389 the switch must mark all the links between CPU ports and their DSA masters
391 and DSA master will be used - the numerically first port from the firmware
395 DSA uses the ``rtnl_link_ops`` mechanism (with a "dsa" ``kind``) to allow
396 changing the DSA master of a user port. The ``IFLA_DSA_MASTER`` u32 netlink
398 device. The DSA master must be a valid candidate based on firmware node
406     # See the DSA master in current use
409         dsa master eth0
412     ip link set swp0 type dsa master eth1
413     ip link set swp1 type dsa master eth0
414     ip link set swp2 type dsa master eth1
415     ip link set swp3 type dsa master eth0
417     # CPU ports in LAG, using explicit assignment of the DSA master
420     ip link set swp0 type dsa master bond0
421     ip link set swp1 type dsa master bond0
422     ip link set swp2 type dsa master bond0
423     ip link set swp3 type dsa master bond0
427         dsa master bond0
429     # CPU ports in LAG, relying on implicit migration of the DSA master
435         dsa master bond0
438 ``IFLA_DSA_MASTER`` netlink attribute is not strictly needed, but rather, DSA
441 when ``bond0`` is destroyed using ``RTM_DELLINK``, DSA migrates the user ports
442 that were assigned to this interface to the first physical DSA master which is
447 static user to CPU port assignment with LAG between DSA masters. It is not
448 possible to statically assign a user port towards a DSA master that has any
452 Live changing of the DSA master (and thus CPU port) affinity of a user port is
455 Physical DSA masters are allowed to join and leave at any time a LAG interface
456 used as a DSA master; however, DSA will reject a LAG interface as a valid
457 candidate for being a DSA master unless it has at least one physical DSA master