Dell PowerStore Service Scripts Guide

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Monitor network traffic (svc_tcpdump)

This service script enables you to monitor network traffic and open a specific interface in order to run a tcpdump operation. You can save all output to rotating files.

Usage

Function	System Operations
Mode	Normal and Service
Usage	General Use
Requires service user password?	No
Requires root privileges?	No
May cause data unavailability?	No
May cause data loss?	No
Scope	Node
Prerequisites	None

Format

svc_tcpdump [-h] [-i <value>] [-w <value>] [-W <value>] 
[-C <value>] [-s <value>] [-t {1,2,3,4}] [-v {1,2,3}] [-D] [-F <value>] 
[-e] [-n] [-q] [-T <value>] [-N {host,file}] [-Q {in,out,inout}]

Optional arguments

Qualifier	Description
-h, --help	Show the help message and exit.
-i, --interface	Specifies the interface that you want to use to capture information. The default interface for the host namespace is mgmt0. The default namespace for file is eth_data0.
-w, --filename	The base file name for the output files. The default is dump.out. NOTE:This option requires root privileges.
-W, --rotations	Specifies the number of files for output. The default is 5, and the maximum is 20.
-C, --size	Specifies the size of each output file in MB. The default is 50, and the maximum is 200.
-s, --snaplen	Captures a specified number of bytes from each packet instead of the default value. The default value is 65535.0.
-t, --timestamp	Specify a specific timestamp command ranging from `1` to `4`. The timestamp commands are as follows: `1`: Do not print a timestamp on each dump line. `2`: Print an unformatted timestamp on each dump line. `3`: Print a delta, which is measured in microseconds, between the current line and the previous line for each dump line. `4`: Print a timestamp in the default format. The default format shows the date before each timestamp.
-v, --verbosity	Specify how verbose you want the output to be. The maximum is `3`.
-D, --dump_intfs	Print the list of network interfaces available on the system and on which the `tcpdump` operation can capture packets.
-F, --input_expr	Specify a file to use as input for the filter expression. The file must be in the /cyc_var/cyc_service/tcpdump directory.
-a, --add_filter	Create a file with filter expression from user input. This option can only be used with the input_expr option. If the input_expr option is present, a filename is created with the value from that option. Otherwise, a random filter filename is generated in the following format: `tcpdump_filter_XXXX.txt`
-e, --llheader	Print the link-level header on each dump line.
-n, --no_addr	Do not convert addresses such as host addresses or port numbers to names.
-q, --quiet	Print less protocol information so that the output is shorter.
-T, --timeout	Specifies the amount of time that can elapse before stopping the trace. The timeout format is xy, where x is a number and y indicates the units that are used to measure time (seconds, minutes, hours, days - for example, `30s`, `10m`, `5h`, `2d`). Set the timeout to no to never stop the trace. The default is no. NOTE:This option requires root privileges.
-N, --namespace	Define the network namespace as host or file. The default is host. The NAS server namespace is file.
-Q, direction	Choose the send or receive direction for which packets should be captured. Possible values are `in`, `out`, and `inout`.