man8/bridge.8: explain self vs master for "bridge fdb add"

The "usually hardware" and "usually software" distinctions make no
sense, try to clarify what these do based on the actual kernel behavior.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/man/man8/bridge.8 b/man/man8/bridge.8
index 1dc0aec83f092c9dd57f876e2289365cf0bb69d7..d0bcd708bb616d4b824e9cb90df4f2f331faaec7 100644 (file)
--- a/man/man8/bridge.8
+++ b/man/man8/bridge.8
@@ -533,12 +533,21 @@ specified.
 .sp
 
 .B self
-- the address is associated with the port drivers fdb. Usually hardware
-  (default).
+- the operation is fulfilled directly by the driver for the specified network
+device. If the network device belongs to a master like a bridge, then the
+bridge is bypassed and not notified of this operation (and if the device does
+notify the bridge, it is driver-specific behavior and not mandated by this
+flag, check the driver for more details). The "bridge fdb add" command can also
+be used on the bridge device itself, and in this case, the added fdb entries
+will be locally terminated (not forwarded). In the latter case, the "self" flag
+is mandatory. The flag is set by default if "master" is not specified.
 .sp
 
 .B master
-- the address is associated with master devices fdb. Usually software.
+- if the specified network device is a port that belongs to a master device
+such as a bridge, the operation is fulfilled by the master device's driver,
+which may in turn notify the port driver too of the address. If the specified
+device is a master itself, such as a bridge, this flag is invalid.
 .sp
 
 .B router