Endace DAG 5.2X, User Manual

Page: 38 / 66

EDM01-33v1 DAG_7.5G4_Card_User_Guide
34 ©2008 Endace Technology Ltd. Confidential - Version 1 - November 2008
Viewing captured data
Data captured in ERF format can be viewed with
dagbits
. For further details on how to use
dagbits
, see dagbits 34 (page ).
Note:
dagbits
decodes and displays ERF header fields and packet contents are displayed
as a Hex dump only. To decode higher level protocols, Endace recommends using a
third party application, see Using third party applications 38 (page ).
Examples
Test live traffic on dag0, stream 0 for 60 seconds running the lctr, flags and fcs tests:
dagbits -vvc -d0:0 -s60 lctr flags fcs
To read a trace log file using dagbits:
dagbits -vvc print -f logname.log | less
To check for errors in the trace:
dagbits -vvc ltcr flags fcs -f logname.log
If
dagbits
reaches the end of the traffic and prints its report then the ERF records were valid.
dagbits
dagbits
is a software utility used to view and test ERF records.
dagbits
can receive data
from either:
•
directly from the DAG card (using the
-d
option), or
•
a ERF data file created by
dagsnap
.
The following is a list options available in
dagbits
:
Options Description
-0
-16
-32
ERF records contain no Link-Layer CRCs.
ERF records contain 16 bit Link-Layer CRCs (PoS).
ERF records contain 32 bit Link-Layer CRCs (PoS and Ethernet).
-a
Set legacy format to ATM (this is the default).
-b
Treat ERF timestamps as big-endian.
-c
Print real-time progress reports as
dagbits
captures traffic. This is a useful
indicator that a test is running correctly.
-C NUM
Sets CRC correction factor for BTX test (0, 16 or 32 bits).
-d DEVICE
--device DEVICE
Use the DAG device referred to by DEVICE. Supported syntax includes 0, dag1,
and /dev/dag3 to refer to DAG cards, and 0:2, dag1:1, and /dev/dag2:0 to refer
to specific streams on cards.
-D NUM
Introduces a NUM nanosecond delay between processing each record.
-e
Set legacy format to Ethernet (default: ATM).
-E NUM
Halt operation after a maximum of NUM errors. This option prevents
dagbits
from creating extremely large output files when being redirected to a file.
-f FILE
Read captured data from FILE.
-h, -?
--help, --usage
Display usage (help) information.
-i API
Use "API" interface for live DAG API capture. Possible options are:
0 DAG 2.4 legacy API interface [dag_offset(3)].
1 DAG 2.5 API interface [dag_advance_stream(3)].
2 DAG 2.5 API interface [dag_rx_stream_next_record(3)].
-I
Assume the ERF contains color information in the pad and offset bytes (for
Ethernet ERFs) or HDLC header bytes (for PoS ERFs) and display this
information as a packet classification and destination memory buffer.
-j NUM
Set the threshold for the jitter test to NUM microseconds.
-m NUM
Print the first NUM errored records only, and then continue to count errors
silently for the duration of the session.