bf5bc3ce8a
There are two possible utilizations so far: - Switch devices that don't support a native insertion/extraction header on the CPU port may still enjoy the benefits of port isolation with a custom VLAN tag. For this, they need to have a customizable TPID in hardware and a new Ethertype to distinguish between real 802.1Q traffic and the private tags used for port separation. - Switches that don't support the deactivation of VLAN awareness, but still want to have a mode in which they accept all traffic, including frames that are tagged with a VLAN not configured on their ports, may use this as a fake to trick the hardware into thinking that the TPID for VLAN is something other than 0x8100. What follows after the ETH_P_DSA_8021Q EtherType is a regular VLAN header (TCI), however there is no other EtherType that can be used for this purpose and doesn't already have a well-defined meaning. ETH_P_8021AD, ETH_P_QINQ1, ETH_P_QINQ2 and ETH_P_QINQ3 expect that another follow-up VLAN tag is present, which is not the case here. Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Suggested-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.