This service script allows you to run a Linux tcpdump operation on a system interface for diagnostic purposes.
The output from this command is saved in rotating files of fixed size. When an output file grows either to the size defined by
-C or to a different maximum size, the output is redirected to another file. This other file has the same base name but a different suffix. The suffix is a digit from 0 to the value defined by either the
-W option or an internally defined maximum rotation value. Rotating files are created in numerical order.
Table 1. Optional arguments Optional arguments, their related descriptions, and any applicable variable usage.
Qualifier
Description
-h,
--help
Show the help message and exit.
-i,
--interface
Specify the interface to be used to capture information. The default interface for the host namespace is
mgmt0; for SDNAS, the default is
eth_mgmt.
-w,
--filename
Specify the base file name for the output files. The default name is
dump.out.
-W,
--rotations
Specify the number of files for output. The default is 5. The maximum number is 20.
-C,
--size
Specify the size of each output file in MB. The default is 50. The maximum size is 200.
-s,
--snaplen
Capture this specified number of bytes of data from each packet rather than the default 65535. 0 means the default value.
-t,
--timestamp
Add the corresponding number (1, 2, 3, or 4) to the timestamp command to specify how you want the timestamp to appear in the output:
Do not print a timestamp on each dump line.
Print an unformatted timestamp on each dump line.
Print a delta (in microseconds) between current and previous line on each dump line.
Print a timestamp in the default format preceded by the date on each dump line.
-v,
--verbosity
Specify the verbosity of the output, with 3 being most verbose.
-D,
--dump_intfs
Print the list of the network interfaces available on the system and on which the tcpdump operation can capture packets.
-F,
--input _expr
Use the file as input for the filter expression. The file should be in the tcpdump directory.
-e,
--llheader
Print the link-level header on each dump line.
-n,
--no_addr
Do not convert addresses such as host addresses, port numbers, and so on, to names.
-q,
--quiet
Print abridged protocol information to make the output lines shorter.
-T,
--timeout
Define the timeout before stopping the trace. The timeout format is
xy, where x is a number and y is the unit of measurement for time (second, minute, hour, day). Some examples are
30s,
10m,
5h,
2d.
If you want the trace to keep running, set the timeout to
no. The default is
no.
-p,
--path
Specify the path for the output file storage; the default is
/opt/sdnas/log/svc_output. The path that is specified must be an existing directory under
/opt/sdnas/log/svc_output.
-y,
--dlink
Set the data link type to
datalinktype to use while capturing packets.
-L,
--list
List active tcpdump sessions.
-K,
--kill
Kill all tcpdump sessions or a specific session by designating its ID.
Data is not available for the Topic
Please provide ratings (1-5 stars).
Please provide ratings (1-5 stars).
Please provide ratings (1-5 stars).
Please select whether the article was helpful or not.
Comments cannot contain these special characters: <>()\