Endace DAG 4.5G2 Card, Руководство пользователя

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EDM 01-18 DAG 4.5G2/G4/GF Card User Guide
Chapter 4:
Capturing Data
Starting a
Session
For a typical data capture session follow the steps listed below:
•
Move to the directory in which you installed the DAG software
•
Load the appropriate driver,
•
Then load the appropriate FPGA image for the DAG card as described in
Load the FPGA Image in Chapter 3: Configuring the Card earlier in this
User Guide.
•
Configure the card’s physical layer and check the integrity of the physical
layer to each DAG card. For example:
dagconfig –d0 default
•
If you are configuring a DAG 4.5GF card and you wish to engage the
failsafe relays, use:
dagwatchdog –d0 –p
Note: For more information on the Failsafe Relay feature please refer
to Failsafe Relays in Chapter 1: Introduction earlier in this user guide.
•
If you wish to use the Data Stream Manager (DSM) feature you will need
to bypass DSM mode to enable you to perform normal capture. You can
revert to normal capture mode using:
dsm_loader –b
•
Start the capture session using:
dagsnap -d0 –v -o tracefile
Note: You can use
-v
to provide user information during a capture
session although you may want to omit it for automated trace runs.
By default
dagsnap
will run indefinitely but can be stopped using CTRL+C .
You can also configure
dagsnap
to run for a fixed time period then exit.
Setting
Captured
Packet Size
Snaplength
Before you begin to capture data you can set the size that you want the
captured packets to be. You can do this using the
dagconfig
tool to define
the packet snaplength (
slen
).
Note: The snaplength value must be a multiple of 8 and in the range 48
to 9600 inclusive.
By default
slen
which is the portion of the packet that you want to capture, is
set to 1536. This means that only the first 1536 bytes of each packet will be
captured. If for example you want to capture only the IP header of each
packet you may want to set the length to a smaller value. Alternatively if you
want to ensure you capture the whole packet you can set the length to a larger
value.
Note: The ERF header is not included in the
slen
value. Therefore a
slen
of 48 will produce a capture record of 48 bytes plus the number of
bytes in the ERF header.
©2005-2006 19 Version 4: August 2006