the SPAN session is only active.Operation users can view the SPAN session through the
command
show monitor session .
11.2.2. Image data flow
11.2.2.1.
Data flow direction
The SPAN session consists of the following three direction of data flow:
The input data stream
：
All of the source port receives the message will be copied to the port of
destination.In a SPAN session, users can monitor one or more source po rt input message.For
some reason (e.g., port security), from the source port input message may be discarded, but
this does not affect the function of SPAN, the newspaper article will still be the mirror to the
port of destination.
The output data stream
：
All messages sent from the source port will be a copy to the
destination port.In a SPAN session, users can monitor one or more source port output message.If
for some reason, a message sent to the source port from other port may be
discarded,similarly, the pa cket will not send to the port of destination.For some reason from
the source port output message format may change,for example, the source port output
after routing message,the message of the source MAC, destination MAC, VLAN ID and TTL
changes,as well, the format of the message copy to the destination port will also change.
Bidirectional data flow
：
Including the above two kinds of data flow.In a SPAN session, the user
can monitor one or more of the source port of the direction of the input and output data stream.
11.2.2.2.
SPAN Traffic
Using SPAN can monitor all communications, including multicast frames, BPDU frame, etc.
11.2.3. Source port
Source port, also known as being monitored, the SPAN session, the data flow on the source port be
monitored,for network analysis and troubleshooting.In a single SPAN session, the user can
monitor the input, output, and bidirectional data flow, and the source port there is no limit to the
number of the big
。
Source port has the following features:
The source port is not AP.
The source port cannot at the same time as the destination port.
Source and destination ports can belong to the same VLAN, can also belong to different VLAN.
11.2.4. Destination port
SPAN session has a destination port (also known as a monitoring port), for message receiving source
port copy. The destination port has the following features:
The destination port is not AP port.
The destination port cannot at the same time as the source port.
