
=head1 NAME

tethereal - Dump and analyze network traffic

=head1 SYNOPSYS

B<tethereal>
S<[ B<-a> capture autostop condition ] ...>
S<[ B<-b> number of ring buffer files [:duration] ]>
S<[ B<-c> count ]>
S<[ B<-d> <layer type>==<selector>,<decode-as protocol> ]>
S<[ B<-D> ]>
S<[ B<-f> capture filter expression ]>
S<[ B<-F> file format ]>
S<[ B<-h> ]>
S<[ B<-i> interface ]> 
S<[ B<-l> ]>
S<[ B<-L> ]>
S<[ B<-n> ]>
S<[ B<-N> resolving flags ]>
S<[ B<-o> preference setting ] ...>
S<[ B<-p> ]>
S<[ B<-q> ]>
S<[ B<-r> infile ]>
S<[ B<-R> display filter expression ]>
S<[ B<-s> snaplen ]>
S<[ B<-S> ]>
S<[ B<-t> time stamp format ]>
S<[ B<-T> pdml|psml|ps|text ]>
S<[ B<-v> ]>
S<[ B<-V> ]>
S<[ B<-w> savefile ]>
S<[ B<-x> ]>
S<[ B<-y> link type ]>
S<[ B<-z> statistics-string ]>
S<[ filter expression ]>

=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.  

B<Ethereal> can read / import the following file formats:

=over 4

=item *
libpcap/WinPcap, tcpdump and various other tools using tcpdump's capture format

=item *
B<snoop> and B<atmsnoop>

=item *
Shomiti/Finisar B<Surveyor> captures

=item *
Novell B<LANalyzer> captures

=item *
Microsoft B<Network Monitor> captures

=item *
AIX's B<iptrace> captures

=item *
Cinco Networks B<NetXRay> captures

=item *
Network Associates Windows-based B<Sniffer> captures

=item *
Network General/Network Associates DOS-based B<Sniffer> (compressed or uncompressed) captures

=item *
AG Group/WildPackets B<EtherPeek>/B<TokenPeek>/B<AiroPeek>/B<EtherHelp>/B<PacketGrabber> captures

=item *
B<RADCOM>'s WAN/LAN analyzer captures

=item *
Network Instruments B<Observer> version 9 captures

=item *
B<Lucent/Ascend> router debug output

=item *
files from HP-UX's B<nettl>

=item *
B<Toshiba's> ISDN routers dump output

=item *
the output from B<i4btrace> from the ISDN4BSD project

=item *
traces from the B<EyeSDN> USB S0.

=item *
the output in B<IPLog> format from the Cisco Secure Intrusion Detection System

=item *
B<pppd logs> (pppdump format)

=item *
the output from VMS's B<TCPIPtrace>/B<TCPtrace>/B<UCX$TRACE> utilities

=item *
the text output from the B<DBS Etherwatch> VMS utility

=item *
Visual Networks' B<Visual UpTime> traffic capture

=item *
the output from B<CoSine> L2 debug

=item *
the output from Accellent's B<5Views> LAN agents

=item *
Endace Measurement Systems' ERF format captures 

=item *
Linux Bluez Bluetooth stack B<hcidump -w> traces

=back

There is no need to tell B<Tethereal> what type of
file you are reading; it will determine the file type by itself. 
B<Tethereal> is also capable of reading any of these file formats if
they are compressed using gzip.  B<Tethereal> recognizes this directly
from the file; the '.gz' extension is not required for this purpose.

If the B<-w> flag is not specified, B<Tethereal> prints a decoded form
of the packets it captures or reads; otherwise, it writes those packets
to the file specified by that flag.

When printing a decoded form of packets, B<Tethereal> prints, 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 printing packets as it captures
them, rather than printing packets from a saved capture file, it won't
print the "frame number" field.  If the B<-V> flag is specified, it
prints instead a view of the details of the packet, showing all the
fields of all protocols in the packet.

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> flag can be used to specify the format in which
to write the file.  The following output formats are supported:

=over 4

=item *
B<libpcap> - libpcap (tcpdump, Ethereal, etc.)

=item *
B<rh6_1libpcap> - Red Hat Linux 6.1 libpcap (tcpdump)

=item *
B<suse6_3libpcap> - SuSE Linux 6.3 libpcap (tcpdump)

=item *
B<modlibpcap> - modified libpcap (tcpdump)

=item *
B<nokialibpcap> - Nokia libpcap (tcpdump)

=item *
B<lanalyzer> - Novell LANalyzer

=item *
B<ngsniffer> - Network Associates Sniffer (DOS-based)

=item *
B<snoop> - Sun snoop

=item *
B<netmon1> - Microsoft Network Monitor 1.x

=item *
B<netmon2> - Microsoft Network Monitor 2.x

=item *
B<ngwsniffer_1_1> - Network Associates Sniffer (Windows-based) 1.1

=item *
B<ngwsniffer_2_0> - Network Associates Sniffer (Windows-based) 2.00x

=item *
B<visual> - Visual Networks traffic capture

=back

This list is also 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.

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.

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> flag was specified) and a read filter if a capture file is being
read (i.e., if a B<-r> flag was specified).

=head1 OPTIONS

=over 4

=item -a

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:

=for man .RS

=for html <P><DL>

=item duration

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

=item filesize

Stop writing to a capture file after it reaches a size of I<value>
kilobytes (where a kilobyte is 1000 bytes, not 1024 bytes).

=for man .RE

=for html </DL>

=item -b

If a maximum capture file size was specified, cause B<Tethereal> to run
in "ring buffer" mode, with the specified number of files.  In "ring
buffer" mode, B<Tethereal> will write to several capture files. 
Their name is based on the number of the file and on the creation date 
and time.

When the first capture file fills up, B<Tethereal> will switch to writing
to the next file, until it fills up the last file, at which point it'll
discard the data in the first file (unless 0 is specified, in which case,
the number of files is unlimited) and start writing to that file and so on.

If the optional duration is specified, B<Tethereal> will switch also 
to the next file when the specified number of seconds has elapsed even
if the current file is not completely fills up.

You can only save files in B<libpcap> format when using a ring buffer.

=item -c

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

=item -d

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> flag 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; if, on your system, a program doing a
network capture must be run from an account with special privileges (for
example, as root), then, if B<Tethereal> is run with the B<-D> flag and
is not run from such an account, it will not list any interfaces.

=item -f

Set the capture filter expression.

=item -F

Set the file format of the output capture file written using the B<-w>
flag.

=item -h

Print the version and options and exits.

=item -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
"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> flag 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,
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.

=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.

=item -n

Disable network object name resolution (such as hostname, TCP and UDP port
names).

=item -N

Turn on name resolving for particular types of addresses and port
numbers, with name resolving for other types of addresses and port
numbers turned off; the argument is a string that may contain the
letters B<m> to enable MAC address resolution, B<n> to enable network
address resolution, and B<t> to enable transport-layer port number
resolution.  This overrides B<-n> if both B<-N> and B<-n> are present.
The letter B<C> enables concurrent (asynchronous) DNS lookups.

=item -o

Set a preference value, overriding the default value and any value read
from a preference file.  The argument to the flag 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, 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) will cause the current count to be
displayed.

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>
flag to calculate statistics and don't want the packet information
printed, just the statistics.

=item -r

Read packet data from I<infile>.

=item -R

Cause the specified filter (which uses the syntax of read 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

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> flag.

=item -t

Set the format of the packet timestamp printed in summary lines.  The
format can be one of 'r' (relative), 'a' (absolute), 'ad' (absolute with
date), or 'd' (delta).  The relative time is the time elapsed between
the first packet and the current packet.  The absolute time is the
actual time the packet was captured, with no date displayed; the
absolute date and time is the actual time and date the packet was
captured.  The delta time is the time since the previous packet was
captured.  The default is relative.

=item -T

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

=for man .RS

=for html <P><DL>

=item 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.

=item 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.

=item 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.

=item 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.

=for man .RE

=for html </DL>

=item -v

Print the version and exit.

=item -V

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

=item -w

Write raw packet data to I<savefile> or to the standard output if
I<savefile> is "-". 

=item -x

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

=item -y

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

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 manual page of tcpdump(8).

=head1 READ FILTER SYNTAX

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

=head1 FILES

The global preferences file, F<preferences>, which is installed in the
F<ethereal> directory under the F<share> subdirectory of the main
installation directory (for example, F</usr/local/share/ethereal>) on
UNIX-compatible systems, and in the main installation directory (for
example, F<C:\Program Files\Ethereal>) on Windows systems, and the
personal preferences file, which is 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, contain system-wide and
personal preference settings, respectively.  The files contain
preference settings of the form I<prefname>B<:>I<value>, one per line,
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; 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.

The system-wide preference file is read first, if it exists, overriding
B<Tethereal>'s default values; the personal preferences file is then
read, if it exists, overriding default values and values read from the
system-wide preference file.

The disabled protocols file, which is F<$HOME/.ethereal/disabled_protos>
on UNIX-compatible systems and F<%APPDATA%\Ethereal\disabled_protos>
(or, if %APPDATA% isn't defined, F<%USERPROFILE%\Application
Data\Ethereal\disabled_protos>) on Windows systems, contain a list of
protocols that have been disabled, so that their dissectors are never
called.  The file contains protocol names, one per line, where the
protocol name is the same name that would be used in a display filter
for the protocol.  A B<#> character starts a comment that runs to the
end of the line.

If the personal F<hosts> file, in F<$HOME/.ethereal/hosts> file on
UNIX-compatible systems, or the F<%APPDATA%\Ethereal\hosts> file (or, if
%APPDATA% isn't defined, the F<%USERPROFILE%\Application
Data\Ethereal\hosts> file) on Windows systems, exists, the entries in
that file are used to resolve IPv4 and IPv6 addresses before any other
attempts are made to resolve them.  That file has the standard F<hosts>
file syntax; each line contains one IP address and name, separated by
whitespace.

The global F<ethers> file, which is found 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, is consulted
to correlate 6-byte hardware addresses to names.  If an address is not
found in the global F<ethers> file, the personal F<ethers> file, in
F<$HOME/.ethereal/ethers> on UNIX-compatible systems, and in
F<%APPDATA%\Ethereal\ethers> (or, if %APPDATA% isn't defined, the
F<%USERPROFILE%\Application Data\Ethereal\ethers> file) on Windows
systems is consulted next.  Each line contains one hardware address and
name, separated by whitespace.  The digits of the hardware address are
separated by either a colon (:), a dash (-), or a period (.).  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 F<manuf> file, which is installed in the F<etc> directory under the
main installation directory (for example, F</usr/local/etc>) on
UNIX-compatible systems, and in the main installation directory (for
example, F<C:\Program Files\Ethereal>) on Windows systems, matches 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> file, 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 of the form

  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.  Trailing zero bytes can be omitted from
address ranges.  That entry, for example, will 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 global F<ipxnets> file, which is found 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, correlates
4-byte IPX network numbers to names.  If a network number is not found
in the global F<ipxnets> file, the personal F<ipxnets> file, in
F<$HOME/.ethereal/ipxnets> on UNIX-compatible systems, and in
F<%APPDATA%\Ethereal\ipxnets> (or, if %APPDATA% isn't defined, the
F<%USERPROFILE%\Application Data\Ethereal\ipxnets> file) on Windows
systems, is consulted next.  The format is the same as the F<ethers>
file, except that each address if four bytes instead of six. 
Additionally, the address can be represented 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

=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>.

=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.
