Endace DAG 4.5G2 Card, Руководство пользователя

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EDM 01-17 DAG 4.5G2/G4/GF Card User Guide
Transmitting
Configuration
The DAG 4.5 card is able to transmit as well as receive packets and can
capture received traffic while transmitting. This allows you to use capture
tools such as
dagsnap
,
dagconvert
, and
dagbits
while
dagflood
is
sending packets.
To configure the DAG card for transmission, you must allocate some
memory to a transmit stream. By default, 16 MB of memory is allocated to
the tx stream and the remainder is allocated to the rx stream.
In the
dagconfig
output,
buffer size =nMB
indicates that a total of
n
MBs
of memory have been allocated to the DAG card in total. You can split this
allocation between the receive and transmit stream buffers to suit your own
requirements. The split is displayed as a ratio as shown below:
mem=X:Y
, where
X
is the memory allocated in MB to the rx stream
Y
is the memory allocated in MB to the tx stream.
For instance you can split 128MB of memory evenly between the tx and rx
streams using:
dagconfig –d0 mem=64:64
Note: You can not change the stream memory allocations while
packet capture or transmission is in progress.
Explicit Packet Transmission
The operating system does not recognize the DAG card as a network
interface and will not respond to ARP, ping, or router discovery protocols.
The DAG card will only transmit packets that are explicitly provided by the
user. This allows you to use the DAG card as a simple traffic load generator.
You can also use it to retransmit previously recorded packet traces. The
packet trace is transmitted at 100% line rate. The packet timing of the
original trace file is not reproduced.
Trace Files
You can use the
dagflood
tool to transmit ERF format trace files, providing
the files contain only ERF records of the type matching the current link
configuration.
If you do not have any ERF trace files available, you can use
daggen
to
generate trace files containing simple traffic patterns. This allows the DAG
card to be used as a test traffic generator.
For further information on using
daggen
please refer to the EDM04-06:
Daggen User Guide available from the Support section of the Endace
website at www.endace.com .
©2005-2006 22 Version 4: August 2006