D.2. tshark: Terminal-based Wireshark

TShark is a terminal oriented version of Wireshark designed for capturing and displaying packets when an interactive user interface isn’t necessary or available. It supports the same options as wireshark. For more information on tshark consult your local manual page (man tshark) or the online version.

Help information available from tshark

TShark (Wireshark) 3.5.0 (v3.5.0rc0-2343-gfa21433c35b1)
Dump and analyze network traffic.
See https://www.wireshark.org for more information.

Usage: tshark [options] ...

Capture interface:
  -i <interface>, --interface <interface>
                           name or idx of interface (def: first non-loopback)
  -f <capture filter>      packet filter in libpcap filter syntax
  -s <snaplen>, --snapshot-length <snaplen>
                           packet snapshot length (def: appropriate maximum)
  -p, --no-promiscuous-mode
                           don't capture in promiscuous mode
  -I, --monitor-mode       capture in monitor mode, if available
  -B <buffer size>, --buffer-size <buffer size>
                           size of kernel buffer (def: 2MB)
  -y <link type>, --linktype <link type>
                           link layer type (def: first appropriate)
  --time-stamp-type <type> timestamp method for interface
  -D, --list-interfaces    print list of interfaces and exit
  -L, --list-data-link-types
                           print list of link-layer types of iface and exit
  --list-time-stamp-types  print list of timestamp types for iface and exit

Capture stop conditions:
  -c <packet count>        stop after n packets (def: infinite)
  -a <autostop cond.> ..., --autostop <autostop cond.> ...
                           duration:NUM - stop after NUM seconds
                           filesize:NUM - stop this file after NUM KB
                              files:NUM - stop after NUM files
                            packets:NUM - stop after NUM packets
Capture output:
  -b <ringbuffer opt.> ..., --ring-buffer <ringbuffer opt.>
                           duration:NUM - switch to next file after NUM secs
                           filesize:NUM - switch to next file after NUM KB
                              files:NUM - ringbuffer: replace after NUM files
                            packets:NUM - switch to next file after NUM packets
                           interval:NUM - switch to next file when the time is
                                          an exact multiple of NUM secs
Input file:
  -r <infile>, --read-file <infile>
                           set the filename to read from (or '-' for stdin)

Processing:
  -2                       perform a two-pass analysis
  -M <packet count>        perform session auto reset
  -R <read filter>, --read-filter <read filter>
                           packet Read filter in Wireshark display filter syntax
                           (requires -2)
  -Y <display filter>, --display-filter <display filter>
                           packet displaY filter in Wireshark display filter
                           syntax
  -n                       disable all name resolutions (def: "mNd" enabled, or
                           as set in preferences)
  -N <name resolve flags>  enable specific name resolution(s): "mnNtdv"
  -d <layer_type>==<selector>,<decode_as_protocol> ...
                           "Decode As", see the man page for details
                           Example: tcp.port==8888,http
  -H <hosts file>          read a list of entries from a hosts file, which will
                           then be written to a capture file. (Implies -W n)
  --enable-protocol <proto_name>
                           enable dissection of proto_name
  --disable-protocol <proto_name>
                           disable dissection of proto_name
  --enable-heuristic <short_name>
                           enable dissection of heuristic protocol
  --disable-heuristic <short_name>
                           disable dissection of heuristic protocol
Output:
  -w <outfile|->           write packets to a pcapng-format file named "outfile"
                           (or '-' for stdout)
  --capture-comment <comment>
                           set the capture file comment, if supported
  -C <config profile>      start with specified configuration profile
  -F <output file type>    set the output file type, default is pcapng
                           an empty "-F" option will list the file types
  -V                       add output of packet tree        (Packet Details)
  -O <protocols>           Only show packet details of these protocols, comma
                           separated
  -P, --print              print packet summary even when writing to a file
  -S <separator>           the line separator to print between packets
  -x                       add output of hex and ASCII dump (Packet Bytes)
  -T pdml|ps|psml|json|jsonraw|ek|tabs|text|fields|?
                           format of text output (def: text)
  -j <protocolfilter>      protocols layers filter if -T ek|pdml|json selected
                           (e.g. "ip ip.flags text", filter does not expand child
                           nodes, unless child is specified also in the filter)
  -J <protocolfilter>      top level protocol filter if -T ek|pdml|json selected
                           (e.g. "http tcp", filter which expands all child nodes)
  -e <field>               field to print if -Tfields selected (e.g. tcp.port,
                           _ws.col.Info)
                           this option can be repeated to print multiple fields
  -E<fieldsoption>=<value> set options for output when -Tfields selected:
     bom=y|n               print a UTF-8 BOM
     header=y|n            switch headers on and off
     separator=/t|/s|<char> select tab, space, printable character as separator
     occurrence=f|l|a      print first, last or all occurrences of each field
     aggregator=,|/s|<char> select comma, space, printable character as
                           aggregator
     quote=d|s|n           select double, single, no quotes for values
  -t a|ad|adoy|d|dd|e|r|u|ud|udoy
                           output format of time stamps (def: r: rel. to first)
  -u s|hms                 output format of seconds (def: s: seconds)
  -l                       flush standard output after each packet
  -q                       be more quiet on stdout (e.g. when using statistics)
  -Q                       only log true errors to stderr (quieter than -q)
  -g                       enable group read access on the output file(s)
  -W n                     Save extra information in the file, if supported.
                           n = write network address resolution information
  -X <key>:<value>         eXtension options, see the man page for details
  -U tap_name              PDUs export mode, see the man page for details
  -z <statistics>          various statistics, see the man page for details
  --export-objects <protocol>,<destdir>
                           save exported objects for a protocol to a directory
                           named "destdir"
  --export-tls-session-keys <keyfile>
                           export TLS Session Keys to a file named "keyfile"
  --color                  color output text similarly to the Wireshark GUI,
                           requires a terminal with 24-bit color support
                           Also supplies color attributes to pdml and psml formats
                           (Note that attributes are nonstandard)
  --no-duplicate-keys      If -T json is specified, merge duplicate keys in an object
                           into a single key with as value a json array containing all
                           values
  --elastic-mapping-filter <protocols> If -G elastic-mapping is specified, put only the
                           specified protocols within the mapping file
Diagnostic output:
  --log-level <level>      sets the active log level ("critical", "warning", etc.)
  --log-fatal <level>      sets level to abort the program ("critical" or "warning")
  --log-domains <[!]list>  comma separated list of the active log domains
  --log-debug <[!]list>    comma separated list of domains with "debug" level
  --log-noisy <[!]list>    comma separated list of domains with "noisy" level
  --log-file <path>        file to output messages to (in addition to stderr)

Miscellaneous:
  -h, --help               display this help and exit
  -v, --version            display version info and exit
  -o <name>:<value> ...    override preference setting
  -K <keytab>              keytab file to use for kerberos decryption
  -G [report]              dump one of several available reports and exit
                           default report="fields"
                           use "-G help" for more help

Dumpcap can benefit from an enabled BPF JIT compiler if available.
You might want to enable it by executing:
 "echo 1 > /proc/sys/net/core/bpf_jit_enable"
Note that this can make your system less secure!