ethereal->wireshark

[obnox/wireshark/wip.git] / doc / tethereal.pod

=head1 NAME

tethereal - Dump and analyze network traffic

=head1 SYNOPSYS

B<tethereal>
S<[ B<-a> E<lt>capture autostop conditionE<gt> ] ...>
S<[ B<-b> E<lt>capture ring buffer optionE<gt>] ...>
S<[ B<-B> E<lt>capture buffer size (Win32 only)E<gt> ] >
S<[ B<-c> E<lt>capture packet countE<gt> ]>
S<[ B<-d> E<lt>layer typeE<gt>==E<lt>selectorE<gt>,E<lt>decode-as protocolE<gt> ]>
S<[ B<-D> ]>
S<[ B<-f> E<lt>capture filterE<gt> ]>
S<[ B<-F> E<lt>file formatE<gt> ]>
S<[ B<-h> ]>
S<[ B<-i> E<lt>capture interfaceE<gt>|- ]> 
S<[ B<-l> ]>
S<[ B<-L> ]>
S<[ B<-n> ]>
S<[ B<-N> E<lt>name resolving flagsE<gt> ]>
S<[ B<-o> E<lt>preference settingE<gt> ] ...>
S<[ B<-p> ]>
S<[ B<-q> ]>
S<[ B<-r> E<lt>infileE<gt> ]>
S<[ B<-R> E<lt>read (display) filterE<gt> ]>
S<[ B<-s> E<lt>capture snaplenE<gt> ]>
S<[ B<-S> ]>
S<[ B<-t> ad|a|r|d ]>
S<[ B<-T> pdml|psml|ps|text ]>
S<[ B<-v> ]>
S<[ B<-V> ]>
S<[ B<-w> E<lt>outfileE<gt>|- ]>
S<[ B<-x> ]>
S<[ B<-X> E<lt>eXtension optionE<gt>]>
S<[ B<-y> E<lt>capture link typeE<gt> ]>
S<[ B<-z> E<lt>statisticsE<gt> ]>

=head1 DESCRIPTION

B<Tethereal> 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.  B<Tethereal>'s native
capture file format is B<libpcap> format, which is also the format used
by B<tcpdump> and various other tools.  

Without any options set, B<Tethereal> will work much like B<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. 

B<Tethereal> is able to detect, read and write the same capture files that 
are supported by B<Ethereal>.
The input file doesn't need a specific filename extension, the file 
format and an optional gzip compression will be automatically detected.
The I<capture file format> section of I<ethereal(1)> or
I<http://www.ethereal.com/docs/man-pages/ethereal.1.html>
provides a detailed description.

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

If the B<-w> option is not specified, B<Tethereal> writes to the standard
output the text of a decoded form of the packets it captures or reads. 
If the B<-w> option is specified, B<Tethereal> 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, B<Tethereal> 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 B<Ethereal>), although if it's writing packets as it captures
them, rather than writting packets from a saved capture file, it won't
show the "frame number" field.  If the B<-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
B<Tethereal> without the B<-w> option, and redirect its standard output to
the file (do I<not> use the B<-w> option).

When writing packets to a file, B<Tethereal>, by default, writes the
file in B<libpcap> format, and writes all of the packets it sees to the
output file.  The B<-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 B<-h> flag.

Read filters in B<Tethereal>, which allow you to select which packets
are to be decoded or written to a file, are very powerful; more fields
are filterable in B<Tethereal> than in other protocol analyzers, and the
syntax you can use to create your filters is richer.  As B<Tethereal>
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
B<Tethereal> 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 B<-f> or B<-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
Tethereal 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
B<-r> option was specified) and a read filter if a capture file is being
read (i.e., if a B<-r> option was specified).

=head1 OPTIONS

=over 4

=item -a  E<lt>capture autostop conditionE<gt>

Specify a criterion that specifies when B<Tethereal> is to stop writing
to a capture file.  The criterion is of the form I<test>B<:>I<value>,
where I<test> is one of:

B<duration>:I<value> Stop writing to a capture file after I<value> seconds have elapsed.

B<filesize>:I<value> Stop writing to a capture file after it reaches a size of I<value>
kilobytes (where a kilobyte is 1024 bytes). If this option 
is used together with the -b option, Ethereal will stop writing to the 
current capture file and switch to the next one if filesize is reached.

B<files>:I<value> Stop writing to capture files after I<value> number of files were written.

=item -b  E<lt>capture ring buffer optionE<gt>

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

The created filenames are based on the filename given with the B<-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 I<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 B<Tethereal> will discard the data in the first file and start 
writing to that file and so on. If the I<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 I<key>B<:>I<value>,
where I<key> is one of:

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

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

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

=item -B  E<lt>capture buffer size (Win32 only)E<gt>

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.

=item -c  E<lt>capture packet countE<gt>

Set the maximum number of packets to read when capturing live
data.

=item -d  E<lt>layer typeE<gt>==E<lt>selectorE<gt>,E<lt>decode-as protocolE<gt>

Specify that if the layer type in question (for example, B<tcp.port> or
B<udp.port> for a TCP or UDP port number) has the specified selector
value, packets should be dissected as the specified protocol.

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

=item -D

Print a list of the interfaces on which B<Tethereal> 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 B<-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 B<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 B<Tethereal> was able to open
that device to do a live capture. Depending on your system you may need to run tethereal from an account 
with special privileges (for example, as root) to be able to capture 
network traffic.
If B<Tethereal -D> is not run from such an account, it will not list 
any interfaces.

=item -f  E<lt>capture filterE<gt>

Set the capture filter expression.

=item -F  E<lt>file formatE<gt>

Set the file format of the output capture file written using the B<-w>
option.  The output written with the B<-w> option is raw packet data, not
text, so there is no B<-F> option to request text output.

=item -h

Print the version and options and exits.

=item -i  E<lt>capture interfaceE<gt>|-

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
"B<tethereal -D>" (described above); a number, as reported by
"B<tethereal -D>", can also be used.  If you're using UNIX, "B<netstat
-i>" or "B<ifconfig -a>" might also work to list interface names,
although not all versions of UNIX support the B<-a> option to B<ifconfig>.

If no interface is specified, B<Tethereal> 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,
B<Tethereal> 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 B<Tethereal> doesn't support capturing from
pipes or stdin!

=item -l

Flush the standard output after the information for each packet is
printed.  (This is not, strictly speaking, line-buffered if B<-V>
was specified; however, it is the same as line-buffered if B<-V> wasn't
specified, as only one line is printed for each packet, and, as B<-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 B<Tethereal> 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 B<Tethereal> sees the
packet and generates that output, rather than seeing it only when the
standard output buffer containing that data fills up.

=item -L

List the data link types supported by the interface and exit. The reported
link types can be used for the B<-y> option.

=item -n

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

=item -N  E<lt>name resolving flagsE<gt>

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 B<-n> if both B<-N> and B<-n> are 
present. If both B<-N> and B<-n> flags are not present, all name resolutions are 
turned on.

The argument is a string that may contain the letters:

B<m> to enable MAC address resolution

B<n> to enable network address resolution

B<t> to enable transport-layer port number resolution

B<C> to enable concurrent (asynchronous) DNS lookups

=item -o  E<lt>preferenceE<gt>:E<lt>valueE<gt>

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 I<prefname>B<:>I<value>, where I<prefname> is the name of the
preference (which is the same name that would appear in the preference
file), and I<value> is the value to which it should be set.

=item -p

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

=item -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 B<-z>
option to calculate statistics and don't want the packet information
printed, just the statistics.

=item -r  E<lt>infileE<gt>

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

=item -R  E<lt>read (display) filterE<gt>

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.

=item -s  E<lt>capture snaplenE<gt>

Set the default snapshot length to use when capturing live data. 
No more than I<snaplen> bytes of each network packet will be read into
memory, or saved to disk.

=item -S

Decode and display packets even while writing raw packet data using the
B<-w> option.

=item -t  ad|a|r|d

Set the format of the packet timestamp printed in summary lines, the default 
is relative. The format can be one of:

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

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

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

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

=item -T  pdml|psml|ps|text

Set the format of the output when viewing decoded packet data.  The
options are one of:

B<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 B<-V> flag.

B<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.

B<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 B<-V> flag was specified.

B<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 B<-V> flag was specified.  This is the default.

=item -v

Print the version and exit.

=item -V

Cause B<Tethereal> to print a view of the packet details rather
than a one-line summary of the packet.

=item -w  E<lt>outfileE<gt>|-

Write raw packet data to I<outfile> or to the standard output if
I<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 B<-w> 
option for this.

=item -x

Cause B<Tethereal> to print a hex and ASCII dump of the packet data
after printing the summary or details.


=item -X E<lt>eXtension optionsE<gt>

Specify an option to be passed to a B<Tethereal> module. The eXtension option
is in the form I<extension_key>B<:>I<value>, where I<extension_key> can be:

B<lua_script>:I<lua_script_filename> tells B<Ethereal> to load the given script in addition to the
default Lua scripts.


=item -y  E<lt>capture link typeE<gt>

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

=item -z  E<lt>statisticsE<gt>

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

Note that the B<-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 B<-q>
option, as that option would suppress the printing of the regular packet
summary output, and must also not use the B<-V> option, as that would
cause packet detail information rather than packet summary information
to be printed.

Currently implemented statistics are:

B<-z> dcerpc,rtt,I<uuid>,I<major>.I<minor>[,I<filter>]

Collect call/reply RTT data for DCERPC interface I<uuid>, 
version I<major>.I<minor>.
Data collected is number of calls for each procedure, MinRTT, MaxRTT 
and AvgRTT. 
Example: use B<-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 B<-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.


B<-z> io,phs[,I<filter>]

Create Protocol Hierarchy Statistics listing both number of packets and bytes.
If no I<filter> is specified the statistics will be calculated for all packets.
If a I<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. 


B<-z> io,stat,I<interval>[,I<filter>][,I<filter>][,I<filter>]...

Collect packet/bytes statistics for the capture in intervals of
I<interval> seconds.  I<Intervals> can be specified either as whole or
fractional seconds.  Interval can be specified in ms resolution.

If no I<filter> is specified the statistics will be calculated for all packets.
If one or more I<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: B<-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: B<-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.

B<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](<field>)<filter>

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: B<-z io,stat,0.010,AVG(smb.time)> does not work.  Use B<-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. 


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

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

Example: B<-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(<field>) 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:  B<-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.



B<-z> conv,I<type>[,I<filter>]

Create a table that lists all conversations that could be seen in the capture.
I<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.


B<-z> proto,colinfo,I<filter>,I<field>

Append all I<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.
I<field> is the display-filter name of a field which value should be placed
in the Info column.
I<filter> is a filter string that controls for which packets the field value
will be presented in the info column. I<field> will only be presented in the
Info column for the packets which match I<filter>.

NOTE: In order for B<Tethereal> to be able to extract the I<field> value
from the packet, I<field> MUST be part of the I<filter> string.  If not,
B<Tethereal> 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

B<-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:

B<-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. 


B<-z> rpc,rtt,I<program>,I<version>[,I<filter>]

Collect call/reply RTT data for I<program>/I<version>.  Data collected
is number of calls for each procedure, MinRTT, MaxRTT and AvgRTT. 
Example: use B<-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 B<-z rpc,rtt,100003,3,nfs.fh.hash==0x12345678> to collect NFS v3
RTT statistics for a specific file.


B<-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.

B<-z> smb,rtt[,I<filter>]

Collect call/reply RTT data for SMB.  Data collected
is number of calls for each SMB command, MinRTT, MaxRTT and AvgRTT. 
Example: use B<-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 B<-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 .

B<-z> smb,sids

When this feature is used B<Tethereal> 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
B<-o "smb.sid_name_snooping:TRUE"> on the B<Tethereal> command line.

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

B<-z> mgcp,rtd[I<,filter>]

Collect requests/response RTD (Response Time Delay) data for MGCP. 
This is similar to B<-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 B<-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 B<-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 .

B<-z> h225,counter[I<,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 the second column.

Example: use B<-z h225,counter>.

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 B<-z "h225,counter,ip.addr==1.2.3.4"> to only collect stats for
H.225 packets exchanged by the host at IP address 1.2.3.4 .

B<-z> h225,srt[I<,filter>]

Collect requests/response SRT (Service Response Time) data for ITU-T H.225 RAS. 
Data collected is number of calls of each ITU-T H.225 RAS Message Type,
Minimum SRT, Maximum SRT, Average SRT, Minimum in Frame, and Maximum in Frame. 
You will also get the number of Open Requests (Unresponded Requests), 
Discarded Responses (Responses without matching request) and Duplicate Messages.
Example: use B<-z h225,srt>.

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 B<-z "h225,srt,ip.addr==1.2.3.4"> to only collect stats for
ITU-T H.225 RAS packets exchanged by the host at IP address 1.2.3.4 .

B<-z> sip,stat[I<,filter>]

This option will activate a counter for SIP messages. You will get the number 
of occurences of each SIP Method and of each SIP Status-Code. Additionally you 
also get the number of resent SIP Messages (only for SIP over UDP).  

Example: use B<-z sip,stat>.

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

If the optional filter string is provided, the stats will only be calculated
on those calls that match that filter.
Example: use B<-z "sip,stat,ip.addr==1.2.3.4"> to only collect stats for
SIP packets exchanged by the host at IP address 1.2.3.4 .

=back

=head1 CAPTURE FILTER SYNTAX

See the manual page of I<tcpdump(8)>.

=head1 READ FILTER SYNTAX

For a complete table of protocol and protocol fields that are filterable
in B<Tethereal> see the I<ethereal-filter(4)> manual page.

=head1 FILES

These files contains various B<Ethereal> configuration values.

=over 4

=item Preferences

The F<preferences> files contain global (system-wide) and personal
preference settings. If the system-wide preference file exists, it is
read first, overriding the default settings. If the personal preferences
file exists, it is read next, overriding any previous values. Note: If
the command line option B<-o> is used (possibly more than once), it will
in turn override values from the preferences files.

The preferences settings are in the form I<prefname>B<:>I<value>,
one per line,
where I<prefname> is the name of the preference
and I<value> is the value to
which it should be set; white space is allowed between B<:> and
I<value>.  A preference setting can be continued on subsequent lines by
indenting the continuation lines with white space.  A B<#> character
starts a comment that runs to the end of the line:

  # Capture in promiscuous mode?
  # TRUE or FALSE (case-insensitive).
  capture.prom_mode: TRUE

The global preferences file is looked for in the F<ethereal> directory
under the F<share> subdirectory of the main installation directory (for
example, F</usr/local/share/ethereal/preferences>) on UNIX-compatible
systems, and in the main installation directory (for example,
F<C:\Program Files\Ethereal\preferences>) on Windows systems.

The personal preferences file is looked for in
F<$HOME/.ethereal/preferences> on
UNIX-compatible systems and F<%APPDATA%\Ethereal\preferences> (or, if
%APPDATA% isn't defined, F<%USERPROFILE%\Application
Data\Ethereal\preferences>) on Windows systems.

=item Disabled (Enabled) Protocols

The F<disabled_protos> files contain system-wide and personal lists of
protocols that have been disabled, so that their dissectors are never
called.  The files contain protocol names, one per line, where the
protocol name is the same name that would be used in a display filter
for the protocol:

  http
  tcp     # a comment

The global F<disabled_protos> file uses the same directory as the global
preferences file.

The personal F<disabled_protos> file uses the same directory as the
personal preferences file.

=item Name Resolution (hosts)

If the personal F<hosts> file exists, it is
used to resolve IPv4 and IPv6 addresses before any other
attempts are made to resolve them.  The file has the standard F<hosts>
file syntax; each line contains one IP address and name, separated by
whitespace. The same directory as for the personal preferences file is
used.

=item Name Resolution (ethers)

The F<ethers> files are consulted to correlate 6-byte hardware addresses to
names. First the personal F<ethers> file is tried and if an address is not
found there the global F<ethers> file is tried next.

Each line contains one hardware address and name, separated by
whitespace.  The digits of the hardware address are separated by colons
(:), dashes (-) or periods (.).  The same separator character must be
used consistently in an address. The following three lines are valid
lines of an F<ethers> file:

  ff:ff:ff:ff:ff:ff          Broadcast
  c0-00-ff-ff-ff-ff          TR_broadcast
  00.00.00.00.00.00          Zero_broadcast

The global F<ethers> file is looked for in the F</etc> directory on
UNIX-compatible systems, and in the main installation directory (for
example, F<C:\Program Files\Ethereal>) on Windows systems.

The personal F<ethers> file is looked for in the same directory as the personal
preferences file.

=item Name Resolution (manuf)

The F<manuf> file is used to match the 3-byte vendor portion of a 6-byte 
hardware address with the manufacturer's name; it can also contain well-known 
MAC addresses and address ranges specified with a netmask.  The format of the 
file is the same as the F<ethers> files, except that entries of the form:

  00:00:0C      Cisco

can be provided, with the 3-byte OUI and the name for a vendor, and
entries such as:

  00-00-0C-07-AC/40     All-HSRP-routers

can be specified, with a MAC address and a mask indicating how many bits
of the address must match. The above entry, for example, has 40
significant bits, or 5 bytes, and would match addresses from
00-00-0C-07-AC-00 through 00-00-0C-07-AC-FF. The mask need not be a
multiple of 8.

The F<manuf> file is looked for in the same directory as the global
preferences file.

=item Name Resolution (ipxnets)

The F<ipxnets> files are used to correlate 4-byte IPX network numbers to 
names. First the global F<ipxnets> file is tried and if that address is not 
found there the personal one is tried next.

The format is the same as the F<ethers>
file, except that each address is four bytes instead of six.
Additionally, the address can be represented as a single hexadecimal
number, as is more common in the IPX world, rather than four hex octets.
For example, these four lines are valid lines of an F<ipxnets> file:

  C0.A8.2C.00              HR
  c0-a8-1c-00              CEO
  00:00:BE:EF              IT_Server1
  110f                     FileServer3

The global F<ipxnets> file is looked for in the F</etc> directory on
UNIX-compatible systems, and in the main installation directory (for
example, F<C:\Program Files\Ethereal>) on Windows systems.

The personal F<ipxnets> file is looked for in the same directory as the
personal preferences file.

=back

=head1 SEE ALSO

I<ethereal-filter(4)> I<ethereal(1)>, I<editcap(1)>, I<tcpdump(8)>, I<pcap(3)>

=head1 NOTES

B<Tethereal> is part of the B<Ethereal> distribution.  The latest version
of B<Ethereal> can be found at B<http://www.ethereal.com>.

HTML versions of the Wireshark project man pages are available at:
http://www.ethereal.com/docs/man-pages

=head1 AUTHORS

B<Tethereal> uses the same packet dissection code that B<Ethereal> does,
as well as using many other modules from B<Ethereal>; see the list of
authors in the B<Ethereal> man page for a list of authors of that code.