Disclosed are methods and apparatus for data tapping within a storage area
network (SAN) and providing tapped data to a third party device, such as
an appliance. In general, mechanisms are provided in a SAN to allow a
data tap of data flowing between an initiator and a target. In one
implementation, a data virtual target (DVT) in created in a network
device to intercept data sent by a specific initiator to a specific
logical unit of a specific target. The data or a copy of the data is sent
to both the specific logical unit of the specific target and to an
appliance. The data routing may be accomplished by use of a virtual
initiator (VI), which is configured to send the data (or a copy of the
data) to the specific target and the appliance. In a transparent mode of
operations, the DVT has a same PWWN (port world wide name) and FCID
(fibre channel identifier) as the specific target. In a first proxy mode
of operation, the DVT has a different PWWN and FCID than the specific
target. In a second proxy mode of operation, the DVT has a same PWWN and
different FCID than the specific target.