man tshark Command

Man page for apt-get tshark Command

Man Page for tshark in Linux

Ubuntu Man Command : man tshark

Man Tshark  Command

This tutorial shows the man page for man tshark in linux.

Open terminal with 'su' access and type the command as shown below:
man tshark

Result of the Command Execution shown below:

TSHARK(1)                                                     The Wireshark Network Analyzer                                                    TSHARK(1)



NAME
tshark Dump and analyze network traffic

SYNOPSIS
tshark [ a ] ... [ b ] ... [ B ]
[ c ] [ C ] [ d ==, ] [ D ] [ e ]
[ E ] [ f ] [ F ] [ h ] [ i | ] [ K ] [ l ] [ L ] [ n ]
[ N ] [ o ] ... [ p ] [ q ] [ r ] [ R ]
[ s ] [ S ] [ t ad|a|r|d|dd|e ] [ T pdml|psml|ps|text|fields ] [ v ] [ V ] [ w | ] [ x ]
[ X ] [ y ] [ z ] [ ]

DESCRIPTION
TShark is a network protocol analyzer. It lets you capture packet data from a live network, or read packets from a previously saved capture file,
either printing a decoded form of those packets to the standard output or writing the packets to a file. TShark's native capture file format is
libpcap format, which is also the format used by tcpdump and various other tools.

Without any options set, TShark will work much like tcpdump. It will use the pcap library to capture traffic from the first available network
interface and displays a summary line on stdout for each received packet.

TShark is able to detect, read and write the same capture files that are supported by Wireshark. The input file doesn't need a specific filename
extension; the file format and an optional gzip compression will be automatically detected. Near the beginning of the DESCRIPTION section of
wireshark(1) or is a detailed description of the way Wireshark handles this, which is the
same way Tshark handles this.

Compressed file support uses (and therefore requires) the zlib library. If the zlib library is not present, TShark will compile, but will be
unable to read compressed files.

If the w option is not specified, TShark writes to the standard output the text of a decoded form of the packets it captures or reads. If the w
option is specified, TShark writes to the file specified by that option the raw data of the packets, along with the packets' time stamps.

When writing a decoded form of packets, TShark writes, by default, a summary line containing the fields specified by the preferences file (which
are also the fields displayed in the packet list pane in Wireshark), although if it's writing packets as it captures them, rather than writing
packets from a saved capture file, it won't show the "frame number" field. If the V option is specified, it writes instead a view of the details
of the packet, showing all the fields of all protocols in the packet.

If you want to write the decoded form of packets to a file, run TShark without the w option, and redirect its standard output to the file (do not
use the w option).

When writing packets to a file, TShark, by default, writes the file in libpcap format, and writes all of the packets it sees to the output file.
The F option can be used to specify the format in which to write the file. This list of available file formats is displayed by the F flag
without a value. However, you can't specify a file format for a live capture.

Read filters in TShark, which allow you to select which packets are to be decoded or written to a file, are very powerful; more fields are
filterable in TShark than in other protocol analyzers, and the syntax you can use to create your filters is richer. As TShark progresses, expect
more and more protocol fields to be allowed in read filters.

Packet capturing is performed with the pcap library. The capture filter syntax follows the rules of the pcap library. This syntax is different
from the read filter syntax. A read filter can also be specified when capturing, and only packets that pass the read filter will be displayed or
saved to the output file; note, however, that capture filters are much more efficient than read filters, and it may be more difficult for TShark
to keep up with a busy network if a read filter is specified for a live capture.

A capture or read filter can either be specified with the f or R option, respectively, in which case the entire filter expression must be
specified as a single argument (which means that if it contains spaces, it must be quoted), or can be specified with command line arguments after
the option arguments, in which case all the arguments after the filter arguments are treated as a filter expression. Capture filters are
supported only when doing a live capture; read filters are supported when doing a live capture and when reading a capture file, but require TShark
to do more work when filtering, so you might be more likely to lose packets under heavy load if you're using a read filter. If the filter is
specified with command line arguments after the option arguments, it's a capture filter if a capture is being done (i.e., if no r option was
specified) and a read filter if a capture file is being read (i.e., if a r option was specified).

OPTIONS
a
Specify a criterion that specifies when TShark is to stop writing to a capture file. The criterion is of the form test:value, where test is
one of:

duration:value Stop writing to a capture file after value seconds have elapsed.

filesize:value Stop writing to a capture file after it reaches a size of value kilobytes (where a kilobyte is 1024 bytes). If this option is
used together with the b option, TShark will stop writing to the current capture file and switch to the next one if filesize is reached. When
reading a capture file, TShark will stop reading the file after the number of bytes read exceeds this number (the complete packet will be
read, so more bytes than this number may be read).

files:value Stop writing to capture files after value number of files were written.

b
Cause TShark to run in "multiple files" mode. In "multiple files" mode, TShark will write to several capture files. When the first capture
file fills up, TShark will switch writing to the next file and so on.

The created filenames are based on the filename given with the w option, the number of the file and on the creation date and time, e.g.
outfile_00001_20050604120117.pcap, outfile_00001_20050604120523.pcap, ...

With the files option it's also possible to form a "ring buffer". This will fill up new files until the number of files specified, at which
point TShark will discard the data in the first file and start writing to that file and so on. If the files option is not set, new files
filled up until one of the capture stop conditions match (or until the disk if full).

The criterion is of the form key:value, where key is one of:

duration:value switch to the next file after value seconds have elapsed, even if the current file is not completely filled up.

filesize:value switch to the next file after it reaches a size of value kilobytes (where a kilobyte is 1024 bytes).

files:value begin again with the first file after value number of files were written (form a ring buffer).

B
Win32 only: set capture buffer size (in MB, default is 1MB). This is used by the the capture driver to buffer packet data until that data can
be written to disk. If you encounter packet drops while capturing, try to increase this size.

c
Set the maximum number of packets to read when capturing live data. If reading a capture file, set the maximum number of packets to read.

C
Run with the given configuration profile.

d ==,
Like Wireshark's Decode As... feature, this lets you specify how a layer type should be dissected. If the layer type in question (for example,
tcp.port or udp.port for a TCP or UDP port number) has the specified selector value, packets should be dissected as the specified protocol.

Example: d tcp.port==8888,http will decode any traffic running over TCP port 8888 as HTTP.

Using an invalid selector or protocol will print out a list of valid selectors and protocol names, respectively.

Example: d . is a quick way to get a list of valid selectors.

Example: d ethertype==0x0800. is a quick way to get a list of protocols that can be selected with an ethertype.

D Print a list of the interfaces on which TShark can capture, and exit. For each network interface, a number and an interface name, possibly
followed by a text description of the interface, is printed. The interface name or the number can be supplied to the i option to specify an
interface on which to capture.

This can be useful on systems that don't have a command to list them (e.g., Windows systems, or UNIX systems lacking ifconfig a); the number
can be useful on Windows 2000 and later systems, where the interface name is a somewhat complex string.

Note that "can capture" means that TShark was able to open that device to do a live capture. Depending on your system you may need to run
tshark from an account with special privileges (for example, as root) to be able to capture network traffic. If TShark D is not run from
such an account, it will not list any interfaces.

e
Add a field to the list of fields to display if T fields is selected. This option can be used multiple times on the command line. At least
one field must be provided if the T fields option is selected.

Example: e frame.number e ip.addr e udp

Giving a protocol rather than a single field will print multiple items of data about the protocol as a single field. Fields are separated by
tab characters by default. E controls the format of the printed fields.

E
Set an option controlling the printing of fields when T fields is selected.

Options are:

header=y|n If y, print a list of the field names given using e as the first line of the output; the field name will be separated using the
same character as the field values. Defaults to n.

separator=/t|/s| Set the separator character to use for fields. If /t tab will be used (this is the default), if /s, s single
space will be used. Otherwise any character that can be accepted by the command line as part of the option may be used.

quote=d|s|n Set the quote character to use to surround fields. d uses double quotes, s single quotes, n no quotes (the default).

f
Set the capture filter expression.

F
Set the file format of the output capture file written using the w option. The output written with the w option is raw packet data, not
text, so there is no F option to request text output. The option F without a value will list the available formats.

h Print the version and options and exits.

i |
Set the name of the network interface or pipe to use for live packet capture.

Network interface names should match one of the names listed in "tshark D" (described above); a number, as reported by "tshark D", can also
be used. If you're using UNIX, "netstat i" or "ifconfig a" might also work to list interface names, although not all versions of UNIX
support the a option to ifconfig.

If no interface is specified, TShark searches the list of interfaces, choosing the first non loopback interface if there are any non loopback
interfaces, and choosing the first loopback interface if there are no non loopback interfaces. If there are no interfaces at all, TShark
reports an error and doesn't start the capture.

Pipe names should be either the name of a FIFO (named pipe) or `` '' to read data from the standard input. Data read from pipes must be in
standard libpcap format.

Note: the Win32 version of TShark doesn't support capturing from pipes!

K
Load kerberos crypto keys from the specified keytab file. This option can be used multiple times to load keys from several files.

Example: K krb5.keytab

l Flush the standard output after the information for each packet is printed. (This is not, strictly speaking, line buffered if V was
specified; however, it is the same as line buffered if V wasn't specified, as only one line is printed for each packet, and, as l is
normally used when piping a live capture to a program or script, so that output for a packet shows up as soon as the packet is seen and
dissected, it should work just as well as true line buffering. We do this as a workaround for a deficiency in the Microsoft Visual C++ C
library.)

This may be useful when piping the output of TShark to another program, as it means that the program to which the output is piped will see the
dissected data for a packet as soon as TShark sees the packet and generates that output, rather than seeing it only when the standard output
buffer containing that data fills up.

L List the data link types supported by the interface and exit. The reported link types can be used for the y option.

n Disable network object name resolution (such as hostname, TCP and UDP port names), the N flag might override this one.

N
Turn on name resolving only for particular types of addresses and port numbers, with name resolving for other types of addresses and port
numbers turned off. This flag overrides n if both N and n are present. If both N and n flags are not present, all name resolutions are
turned on.

The argument is a string that may contain the letters:

m to enable MAC address resolution

n to enable network address resolution

t to enable transport layer port number resolution

C to enable concurrent (asynchronous) DNS lookups

o :
Set a preference value, overriding the default value and any value read from a preference file. The argument to the option is a string of the
form prefname:value, where prefname is the name of the preference (which is the same name that would appear in the preference file), and value
is the value to which it should be set.

p Don't put the interface into promiscuous mode. Note that the interface might be in promiscuous mode for some other reason; hence, p cannot
be used to ensure that the only traffic that is captured is traffic sent to or from the machine on which TShark is running, broadcast traffic,
and multicast traffic to addresses received by that machine.

q When capturing packets, don't display the continuous count of packets captured that is normally shown when saving a capture to a file;
instead, just display, at the end of the capture, a count of packets captured. On systems that support the SIGINFO signal, such as various
BSDs, you can cause the current count to be displayed by typing your "status" character (typically control T, although it might be set to
"disabled" by default on at least some BSDs, so you'd have to explicitly set it to use it).

When reading a capture file, or when capturing and not saving to a file, don't print packet information; this is useful if you're using a z
option to calculate statistics and don't want the packet information printed, just the statistics.

r
Read packet data from infile, can be any supported capture file format (including gzipped files). It's not possible to use named pipes or
stdin here!

R
Cause the specified filter (which uses the syntax of read/display filters, rather than that of capture filters) to be applied before printing
a decoded form of packets or writing packets to a file; packets not matching the filter are discarded rather than being printed or written.

s
Set the default snapshot length to use when capturing live data. No more than snaplen bytes of each network packet will be read into memory,
or saved to disk. A value of 0 specifies a snapshot length of 65535, so that the full packet is captured; this is the default.

S Decode and display packets even while writing raw packet data using the w option.

t ad|a|r|d|dd|e
Set the format of the packet timestamp printed in summary lines. The format can be one of:

ad absolute with date: The absolute date and time is the actual time and date the packet was captured

a absolute: The absolute time is the actual time the packet was captured, with no date displayed

r relative: The relative time is the time elapsed between the first packet and the current packet

d delta: The delta time is the time since the previous packet was captured

dd delta_displayed: The delta_displayed time is the time since the previous displayed packet was captured

e epoch: The time in seconds since epoch (Jan 1, 1970 00:00:00)

The default format is relative.

T pdml|psml|ps|text|fields
Set the format of the output when viewing decoded packet data. The options are one of:

pdml Packet Details Markup Language, an XML based format for the details of a decoded packet. This information is equivalent to the packet
details printed with the V flag.

psml Packet Summary Markup Language, an XML based format for the summary information of a decoded packet. This information is equivalent to
the information shown in the one line summary printed by default.

ps PostScript for a human readable one line summary of each of the packets, or a multi line view of the details of each of the packets,
depending on whether the V flag was specified.

text Text of a human readable one line summary of each of the packets, or a multi line view of the details of each of the packets, depending
on whether the V flag was specified. This is the default.

fields The values of fields specified with the e option, in a form specified by the E option.

v Print the version and exit.

V Cause TShark to print a view of the packet details rather than a one line summary of the packet.

w |
Write raw packet data to outfile or to the standard output if outfile is ' '.

NOTE: w provides raw packet data, not text. If you want text output you need to redirect stdout (e.g. using '>'), don't use the w option for
this.

x Cause TShark to print a hex and ASCII dump of the packet data after printing the summary or details.

X
Specify an option to be passed to a TShark module. The eXtension option is in the form extension_key:value, where extension_key can be:

lua_script:lua_script_filename tells Wireshark to load the given script in addition to the default Lua scripts.

y
Set the data link type to use while capturing packets. The values reported by L are the values that can be used.

z
Get TShark to collect various types of statistics and display the result after finishing reading the capture file. Use the q flag if you're
reading a capture file and only want the statistics printed, not any per packet information.

Note that the z proto option is different it doesn't cause statistics to be gathered and printed when the capture is complete, it modifies
the regular packet summary output to include the values of fields specified with the option. Therefore you must not use the q option, as
that option would suppress the printing of the regular packet summary output, and must also not use the V option, as that would cause packet
detail information rather than packet summary information to be printed.

Currently implemented statistics are:

z dcerpc,rtt,uuid,major.minor[,filter]

Collect call/reply RTT data for DCERPC interface uuid, version major.minor. Data collected is number of calls for each procedure, MinRTT,
MaxRTT and AvgRTT. Example: use z dcerpc,rtt,12345778 1234 abcd ef00 0123456789ac,1.0 to collect data for CIFS SAMR Interface. This option
can be used multiple times on the command line.

If the optional filterstring is provided, the stats will only be calculated on those calls that match that filter. Example: use z
dcerpc,rtt,12345778 1234 abcd ef00 0123456789ac,1.0,ip.addr==1.2.3.4 to collect SAMR RTT statistics for a specific host.

z io,phs[,filter]

Create Protocol Hierarchy Statistics listing both number of packets and bytes. If no filter is specified the statistics will be calculated
for all packets. If a filters is specified statistics will be only calculated for those packets that match the filter.

This option can be used multiple times on the command line.

z io,stat,interval[,filter][,filter][,filter]...

Collect packet/bytes statistics for the capture in intervals of interval seconds. Intervals can be specified either as whole or fractional
seconds. Interval can be specified in ms resolution. If Interval is 0, the statistics will be calculated over all packets.

If no filter is specified the statistics will be calculated for all packets. If one or more filters are specified statistics will be
calculated for all filters and presented with one column of statistics for each filter.

This option can be used multiple times on the command line.

Example: z io,stat,1,ip.addr==1.2.3.4 to generate 1 second statistics for all traffic to/from host 1.2.3.4.

Example: z "io,stat,0.001,smb&ip.addr==1.2.3.4" to generate 1ms statistics for all SMB packets to/from host 1.2.3.4.

The examples above all use the standard syntax for generating statistics which only calculates the number of packets and bytes in each
interval.

io,stat can also do much more statistics and calculate COUNT(), SUM(), MIN(), MAX(), and AVG() using a slightly different filter syntax:

[COUNT|SUM|MIN|MAX|AVG]()

NOTE: One important thing to note here is that the field that the calculation is based on MUST also be part of the filter string or else the
calculation will fail.

So: z io,stat,0.010,AVG(smb.time) does not work. Use z io,stat,0.010,AVG(smb.time)smb.time instead. Also be aware that a field can exist
multiple times inside the same packet and will then be counted multiple times in those packets.

NOTE: A second important thing to note is that the system setting for decimal separator is set to "."! If it is set to "," the statistics will
not be displayed per filter.

COUNT() can be used on any type which has a display filter name. It will count how many times this particular field is encountered in
the filtered packet list.

Example: z io,stat,0.010,COUNT(smb.sid)smb.sid This will count the total number of SIDs seen in each 10ms interval.

SUM() can only be used on named fields of integer type. This will sum together every occurence of this fields value for each interval.

Example: z io,stat,0.010,SUM(frame.pkt_len)frame.pkt_len This will report the total number of bytes seen in all the packets within an
interval.

MIN/MAX/AVG() can only be used on named fields that are either integers or relative time fields. This will calculate maximum/minimum
or average seen in each interval. If the field is a relative time field the output will be presented in seconds and three digits after the
decimal point. The resolution for time calculations is 1ms and anything smaller will be truncated.

Example: z
"io,stat,0.010,smb.time&ip.addr==1.1.1.1,MIN(smb.time)smb.time&ip.addr==1.1.1.1,MAX(smb.time)smb.time&ip.addr==1.1.1.1,MAX(smb.time)smb.time&ip.addr==1.1.1.1"

This will calculate statistics for all smb response times we see to/from host 1.1.1.1 in 10ms intervals. The output will be displayed in 4
columns; number of packets/bytes, minimum response time, maximum response time and average response time.

z conv,type[,filter]

Create a table that lists all conversations that could be seen in the capture. type specifies which type of conversation we want to generate
the statistics for; currently the supported ones are

"eth" Ethernet
"fc" Fibre Channel
"fddi" FDDI
"ip" IP addresses
"ipx" IPX addresses
"tcp" TCP/IP socket pairs Both IPv4 and IPv6 are supported
"tr" Token Ring
"udp" UDP/IP socket pairs Both IPv4 and IPv6 are supported

If the optional filter string is specified, only those packets that match the filter will be used in the calculations.

The table is presented with one line for each conversation and displays number of packets/bytes in each direction as well as total number of
packets/bytes. The table is sorted according to total number of bytes.

z proto,colinfo,filter,field

Append all field values for the packet to the Info column of the one line summary output. This feature can be used to append arbitrary fields
to the Info column in addition to the normal content of that column. field is the display filter name of a field which value should be placed
in the Info column. filter is a filter string that controls for which packets the field value will be presented in the info column. field
will only be presented in the Info column for the packets which match filter.

NOTE: In order for TShark to be able to extract the field value from the packet, field MUST be part of the filter string. If not, TShark will
not be able to extract its value.

For a simple example to add the "nfs.fh.hash" field to the Info column for all packets containing the "nfs.fh.hash" field, use

z proto,colinfo,nfs.fh.hash,nfs.fh.hash

To put "nfs.fh.hash" in the Info column but only for packets coming from host 1.2.3.4 use:

z "proto,colinfo,nfs.fh.hash & ip.src==1.2.3.4,nfs.fh.hash"

This option can be used multiple times on the command line.

z rpc,rtt,program,version[,filter]

Collect call/reply RTT data for program/version. Data collected is number of calls for each procedure, MinRTT, MaxRTT and AvgRTT. Example:
use z rpc,rtt,100003,3 to collect data for NFS v3. This option can be used multiple times on the command line.

If the optional filterstring is provided, the stats will only be calculated on those calls that match that filter. Example: use z
rpc,rtt,100003,3,nfs.fh.hash==0x12345678 to collect NFS v3 RTT statistics for a specific file.

z rpc,programs

Collect call/reply RTT data for all known ONC RPC programs/versions. Data collected is number of calls for each protocol/version, MinRTT,
MaxRTT and AvgRTT. This option can only be used once on the command line.

z rtp,streams

Collect statistics for all RTP streams and calculate max. delta, max. and mean jitter and packet loss percentages.

z smb,rtt[,filter]

Collect call/reply RTT data for SMB. Data collected is number of calls for each SMB command, MinRTT, MaxRTT and AvgRTT. Example: use z
smb,rtt. The data will be presented as separate tables for all normal SMB commands, all Transaction2 commands and all NT Transaction
commands. Only those commands that are seen in the capture will have its stats displayed. Only the first command in a xAndX command chain
will be used in the calculation. So for common SessionSetupAndX + TreeConnectAndX chains, only the SessionSetupAndX call will be used in the
statistics. This is a flaw that might be fixed in the future.

This option can be used multiple times on the command line.

If the optional filterstring is provided, the stats will only be calculated on those calls that match that filter. Example: use z
"smb,rtt,ip.addr==1.2.3.4" to only collect stats for SMB packets echanged by the host at IP address 1.2.3.4 .

z smb,sids

When this feature is used TShark will print a report with all the discovered SID and account name mappings. Only those SIDs where the account
name is known will be presented in the table.

For this feature to work you will need to either to enable "Edit/Preferences/Protocols/SMB/Snoop SID to name mappings" in the preferences or
you can override the preferences by specifying o "smb.sid_name_snooping:TRUE" on the TShark command line.

The current methods used by TShark to find the SID >name mapping is relatively restricted but is hoped to be expanded in the future.

z mgcp,rtd[,filter]

Collect requests/response RTD (Response Time Delay) data for MGCP. This is similar to z smb,rtt). Data collected is number of calls for each
known MGCP Type, MinRTD, MaxRTD and AvgRTD. Additionally you get the number of duplicate requests/responses, unresponded requests, responses
,which don't match with any request. Example: use z mgcp,rtd.

This option can be used multiple times on the command line.

If the optional filterstring is provided, the stats will only be calculated on those calls that match that filter. Example: use z
"mgcp,rtd,ip.addr==1.2.3.4" to only collect stats for MGCP packets exchanged by the host at IP address 1.2.3.4 .

z megaco,rtd[,filter]

Collect requests/response RTD (Response Time Delay) data for MEGACO. This is similar to z smb,rtt). Data collected is number of calls for
each known MEGACO Type, MinRTD, MaxRTD and AvgRTD. Additionally you get the number of duplicate requests/responses, unresponded requests,
responses ,which don't match with any request. Example: use z megaco,rtd.

This option can be used multiple times on the command line.

If the optional filterstring is provided, the stats will only be calculated on those calls that match that filter. Example: use z
"megaco,rtd,ip.addr==1.2.3.4" to only collect stats for MEGACO packets exchanged by the host at IP address 1.2.3.4 .

z h225,counter[,filter]

Count ITU T H.225 messages and their reasons. In the first column you get a list of H.225 messages and H.225 message reasons, which occur in
the current capture file. The number of occurences of each message or reason is displayed in t


Related Topics

Apt Get Commands