=head1 NAME

ethereal - Interactively browse network traffic

=head1 SYNOPSYS

B<ethereal>
S<[ B<-a> capture autostop condition ] ...>
S<[ B<-b> number of ring buffer files ]>
S<[ B<-B> byte view height ]>
S<[ B<-c> count ]>
S<[ B<-f> capture filter expression ]>
S<[ B<-h> ]>
S<[ B<-i> interface ]> 
S<[ B<-k> ]>
S<[ B<-l> ]>
S<[ B<-m> font ]>
S<[ B<-n> ]>
S<[ B<-N> resolving flags ] >
S<[ B<-o> preference setting ] ...>
S<[ B<-p> ]>
S<[ B<-P> packet list height ]>
S<[ B<-Q> ]>
S<[ B<-r> infile ]>
S<[ B<-R> display filter expression ]>
S<[ B<-S> ]>
S<[ B<-s> snaplen ]>
S<[ B<-T> tree view height ]>
S<[ B<-t> time stamp format ]>
S<[ B<-v> ]>
S<[ B<-w> savefile]>
S<[ B<-z> statistics-string ]>
S<[ infile ]>

=head1 DESCRIPTION

B<Ethereal> is a GUI network protocol analyzer.  It lets you
interactively browse packet data from a live network or from a
previously saved capture file.  B<Ethereal>'s native capture file format
is B<libpcap> format, which is also the format used by B<tcpdump> and
various other tools.  In addition, B<Ethereal> can read capture files
from B<snoop> and B<atmsnoop>, Shomiti/Finisar B<Surveyor>, Novell
B<LANalyzer>, Network General/Network Associates DOS-based B<Sniffer>
(compressed or uncompressed), Microsoft B<Network Monitor>, AIX's
B<iptrace>, Cinco Networks B<NetXRay>, Network Associates Windows-based
B<Sniffer>, AG Group/WildPackets B<EtherPeek>/B<TokenPeek>/B<AiroPeek>,
B<RADCOM>'s WAN/LAN analyzer, B<Lucent/Ascend> router debug output,
HP-UX's B<nettl>, the dump output from B<Toshiba's> ISDN routers, the
output from B<i4btrace> from the ISDN4BSD project, the output in
B<IPLog> format from the Cisco Secure Intrusion Detection System, B<pppd
logs> (pppdump format), the output from VMS's B<TCPIPtrace> utility, the
text output from the B<DBS Etherwatch> VMS utility, traffic capture
files from Visual Networks' Visual UpTime, and the output from B<CoSine> 
L2 debug.  There is no need to tell B<Ethereal> what type of file you 
are reading; it will determine the file type by itself.  B<Ethereal> 
is also capable of reading any of these file formats if they are 
compressed using gzip.  B<Ethereal> recognizes this directly from the 
file; the '.gz' extension is not required for this purpose.

Like other protocol analyzers, B<Ethereal>'s main window shows 3 views
of a packet.  It shows a summary line, briefly describing what the
packet is.  A protocol tree is shown, allowing you to drill down to
exact protocol or field that you interested in.  Finally, a hex dump
shows you exactly what the packet looks like when it goes over the wire.

In addition, B<Ethereal> has some features that make it unique.  It can
assemble all the packets in a TCP conversation and show you the ASCII
(or EBCDIC, or hex) data in that conversation.  Display filters in
B<Ethereal> are very powerful; more fields are filterable in B<Ethereal>
than in other protocol analyzers, and the syntax you can use to create
your filters is richer.  As B<Ethereal> progresses, expect more and more
protocol fields to be allowed in display 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 display filter syntax.

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

The pathname of a capture file to be read can be specified with the
B<-r> option or can be specified as a command-line argument.

=head1 OPTIONS

=over 4

Most users will want to start B<Ethereal> without options and configure
it from the menus instead. Those users may just skip this section.

=item -a

Specify a criterion that specifies when B<Ethereal> 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<Ethereal> to run
in "ring buffer" mode, with the specified number of files.  In "ring
buffer" mode, B<Ethereal> will write to several capture files; the name
of the first file, while the capture is in progress, will be the name
specified by the B<-w> flag, and subsequent files with have .I<n>
appended, with I<n> counting up.

When the first capture file fills up, B<Ethereal> 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 and start writing to that file.  When
that file fills up, B<Ethereal> will discard the data in the next file
and start writing to it, and so on.

When the capture completes, the files will be renamed to have names
based on the number of the file and on the date and time at which
packets most recently started being written to the file.

=item -B

Set the initial height of the byte view (bottom) pane.

=item -c

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

=item -f

Set the capture filter expression.

=item -h

Print the version and options and exit.

=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>".  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>.

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 -k

Start the capture session immediately.  If the B<-i> flag was
specified, the capture uses the specified interface.  Otherwise,
B<Ethereal> 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<Ethereal> reports an error and
doesn't start the capture.

=item -l

Turn on automatic scrolling if the packet display is being updated
automatically as packets arrive during a capture (as specified by the
B<-S> flag).

=item -m

Set the name of the font used by B<Ethereal> for most text. 
B<Ethereal> will construct the name of the bold font used for the data
in the byte view pane that corresponds to the field selected in the
protocol tree pane from the name of the main text font.

=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.

=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<Ethereal> is running,
broadcast traffic, and multicast traffic to addresses received by that
machine.

=item -P

Set the initial height of the packet list (top) pane.

=item -Q

Cause B<Ethereal> to exit after the end of capture session (useful in
batch mode with B<-c> option for instance); this option requires the
B<-i> and B<-w> parameters.

=item -r

Read packet data from I<infile>.

=item -R

When reading a capture file specified with the B<-r> flag, causes the
specified filter (which uses the syntax of display filters, rather than
that of capture filters) to be applied to all packets read from the
capture file; packets not matching the filter are discarded.

=item -S

Perform the live packet capture in a separate process, and automatically
update the packet display as packets are seen.

=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 -T

Set the initial height of the tree view (middle) pane.

=item -t

Set the format of the packet timestamp displayed in the packet list
window.  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 -v

Print the version and exit.

=item -w

Set the default capture file name.

=item -z

Get B<Ethereal> to collect various types of statistics and display the result
in a window that updates in semi-real time.
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,stat

Collect frame/bytes statistics for the capture in intervals of 1 seconds.
This option will open a window with up to 5 color-coded graphs where
number-of-frames-per-second or number-of-bytes-per-second statistics
can be calculated and displayed.

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

This graph window can also be opened from the Tools:Statistics:Traffic:IO-Stat
menu item.


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

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 .

=back

=head1 INTERFACE

=head2 MENU ITEMS

=over 4

=item File:Open, File:Close, File:Reload

Open, close, or reload a capture file.  The I<File:Open> dialog box
allows a filter to be specified; when the capture file is read, the
filter is applied to all packets read from the file, and packets not
matching the filter are discarded.

=item File:Save, File:Save As

Save the current capture, or the packets currently displayed from that
capture, to a file.  Check boxes let you select whether to save all
packets, or just those that have passed the current display filter and/or
those that are currently marked, and an option menu lets you select (from 
a list of file formats in which at particular capture, or the packets 
currently displayed from that capture, can be saved), a file format in 
which to save it.

=item File:Print

Print, for all the packets in the current capture, either the summary
line for the packet or the protocol tree view of the packet; when
printing the protocol tree view, the hex dump of the packet can be
printed as well.  Printing options can be set with the
I<Edit:Preferences> menu item, or in the dialog box popped up by this
item.

=item File:Print Packet

Print a fully-expanded protocol tree view of the currently-selected
packet.  Printing options can be set with the I<Edit:Preferences> menu
item.

=item File:Quit

Exit the application.

=item Edit:Find Frame

Search forward or backward, starting with the currently selected packet
(or the most recently selected packet, if no packet is selected), for a
packet matching a given display filter expression.

=item Edit:Find Next

Search forward, starting with the currently selected packet
(or the most recently selected packet, if no packet is selected), for a
packet matching the filter from the previous search.

=item Edit:Find Previous

Search backward, starting with the currently selected packet (or the
most recently selected packet, if no packet is selected), for a packet
matching the filter from the previous search.

=item Edit:Go To Frame

Go to a particular numbered packet.

=item Edit:Mark Frame

Mark (or unmark if currently marked) the selected packet.  The field
"frame.marked" is set for frames that are marked, so that, for example,
a display filters can be used to display only marked frames, and so that
the L<Find Frame> menu item can be used to find the next or previous
marked frame.

=item Edit:Mark All Frames

Mark all packets that are currently displayed.

=item Edit:Unmark All Frames

Unmark all packets that are currently displayed.

=item Edit:Preferences

Set the packet printing, column display, TCP stream coloring, and GUI
options (see L<"Preferences"> below).

=item Edit:Capture Filters

Edit the saved list of capture filters, allowing filters to be added,
changed, or deleted.

=item Edit:Display Filters

Edit the saved list of display filters, allowing filters to be added,
changed, or deleted.

=item Edit:Protocols

Allow protocol dissection to be enabled or disabled for a specific
protocol.  Individual protocols can be enabled or disabled by clicking
on them in the list or by highlighting them and pressing the space bar.
The entire list can be enabled, disabled, or inverted using the buttons
below the list.

When a protocol is disabled, dissection in a particular packet stops
when that protocol is reached, and Ethereal moves on to the next packet.
Any higher-layer protocols that would otherwise have been processed will
not be displayed.  For example, disabling TCP will prevent the dissection
and display of TCP, HTTP, SMTP, Telnet, and any other protocol exclusively
dependent on TCP.

=item Capture:Start

Initiate a live packet capture (see L<"Capture Options"> below).  A
temporary file will be created to hold the capture.  The location of the
file can be chosen by setting your TMPDIR environment variable before
starting B<Ethereal>.  Otherwise, the default TMPDIR location is
system-dependent, but is likely either F</var/tmp> or F</tmp>.

=item Capture:Stop

In a capture that updates the packet display as packets arrive (so that
Ethereal responds to user input other than pressing the "Stop" button in
the capture packet statistics dialog box), stop the capture.

=item Display:Options

Pop up a dialog allowing you to set the format of the packet timestamp
displayed in the packet list window to relative, absolute, absolute date
and time, or delta, to enable or disable the automatic scrolling of the
packet list while a live capture is in progress or to enable or disable
translation of addresses to names in the display.

=item Display:Match

Create a display filter, or add to the display filter strip at the
bottom, a display filter based on the data currently highlighted in the
protocol tree, and apply the filter.

If that data is a field that can be tested in a display filter
expression, the display filter will test that field; otherwise, the
display filter will be based on absolute offset within the packet, and
so could be unreliable if the packet contains protocols with
variable-length headers, such as a source-routed token-ring packet.

The B<Selected> option creates a display filter that tests for a match
of the data; the B<Not Selected> option creates a display filter that
tests for a non-match of the data.  The B<And Selected>, B<Or Selected>,
B<And Not Selected>, and B<Or Not Selected> options add to the end of
the display filter in the strip at the bottom an AND or OR operator
followed by the new display filter expression.

=item Display:Prepare

Create a display filter, or add to the display filter strip at the
bottom, a display filter based on the data currently highlighted in the
protocol tree, but don't apply the filter.

=item Display:Colorize Display

Change the foreground and background colors of the packet information in
the list of packets, based upon display filters.  The list of display
filters is applied to each packet sequentially.  After the first display
filter matches a packet, any additional display filters in the list are
ignored.  Therefore, if you are filtering on the existence of protocols,
you should list the higher-level protocols first, and the lower-level
protocols last.

=item Display:Collapse All

Collapse the protocol tree branches.

=item Display:Expand All

Expand all branches of the protocol tree.

=item Display:Expand All

Expands all branches of the protocol tree.

=item Display:Show Packet In New Window

Create a new window containing a protocol tree view and a hex dump
window of the currently selected packet; this window will continue to
display that packet's protocol tree and data even if another packet is
selected.

=item Display:User Specified Decodes

Create a new window showing whether any protocol ID to dissector
mappings have been changed by the user.  This window also allows the
user to reset all decodes to their default values.

=item Tools:Plugins

See what dynamically loadable dissector plugin modules have been loaded
(see I<"Plugins"> below).

=item Tools:Follow TCP Stream

If you have a TCP packet selected, display the contents of the data
stream for the TCP connection to which that packet belongs, as text, in
a separate window, and leave the list of packets in a filtered state,
with only those packets that are part of that TCP connection being
displayed.  You can revert to your old view by pressing ENTER in the
display filter text box, thereby invoking your old display filter (or
resetting it back to no display filter).

The window in which the data stream is displayed lets you select whether
to display:

=over 4

=item

whether to display the entire conversation, or one or the other side of
it;

=item

whether the data being displayed is to be treated as ASCII or EBCDIC
text or as raw hex data;

=back

=back

=over 4

=item

and lets you print what's currently being displayed, using the same
print options that are used for the I<File:Print Packet> menu item, or
save it as text to a file.

=back

=item Tools:Decode As

If you have a packet selected, present a dialog allowing you to change
which dissectors are used to decode this packet.  The dialog has one
panel each for the link layer, network layer and transport layer
protocol/port numbers, and will allow each of these to be changed
independently.  For example, if the selected packet is a TCP packet to
port 12345, using this dialog you can instruct Ethereal to decode all
packets to or from that TCP port as HTTP packets.

=item Tools:Go To Corresponding Frame

If a field in the protocol tree pane containing a frame number is
selected, go to the frame number specified by that field.  (This works
only if the dissector that put that entry into the protocol tree put it
into the tree as a filterable field rather than just as text.)  This can
be used, for example, to go to the frame for the request corresponding
to a reply, or the reply corresponding to a request, if that frame
number has been put into the protocol tree.

=item Tools:Protocol Hierarchy Statistics

Show the number of packets, and the number of bytes in those packets,
for each protocol in the trace.  It organizes the protocols in the same
hierarchy in which they were found in the trace.  Besides counting the
packets in which the protocol exists, a count is also made for packets
in which the protocol is the last protocol in the stack.  These
last-protocol counts show you how many packets (and the byte count
associated with those packets) B<ended> in a particular protocol.  In
the table, they are listed under "End Packets" and "End Bytes".

=item Tools:Statistics:ONC-RPC:RTT

Open a window to display statistics for an arbitrary ONC-RPC program interface
and display B<Procedure>, B<Number of Calls>, B<Minimum RTT>, B<Maximum RTT> and B<Average RTT> for all procedures for that program/version.
These windows opened will update in semi-real time to reflect changes when
doing live captures or when reading new capture files into B<Ethereal>.

This dialog will also allow an optional filter string to be used.
If an optional filter string is used only such ONC-RPC request/response pairs 
that match that filter will be used to calculate the statistics. If no filter 
string is specified all request/response pairs will be used.

=item Tools:Statistics:ONC-RPC:Programs

This dialog will open a window showing aggregated RTT statistics for all
ONC-RPC Programs/versions that exist in the capture file.

=item Tools:Statistics:DCE-RPC:RTT

Open a window to display statistics for an arbitrary DCE-RPC program interface
and display B<Procedure>, B<Number of Calls>, B<Minimum RTT>, B<Maximum RTT> and B<Average RTT> for all procedures for that program/version.
These windows opened will update in semi-real time to reflect changes when
doing live captures or when reading new capture files into B<Ethereal>.

This dialog will also allow an optional filter string to be used.
If an optional filter string is used only such DCE-RPC request/response pairs 
that match that filter will be used to calculate the statistics. If no filter 
string is specified all request/response pairs will be used.

=item Tools:Statistics:Traffic:IO-Stat

Open a window where up to 5 graphs in different colors can be displayed
to indicate number of frames or number of bytes per second for all packets
matching the specified filter.
By default only one graph will be displayed showing number of frames per second.

The top part of the window contains the graphs and scales for the X and Y axis.
If the graph is too long to fit inside the window there is a horizontal scrollbar below the drawing area that can scroll the graphs to the left or the right.
The horizontal axis displays the time into the capture and the vertical axis will display the measured quantity at that time.

Below the drawing area and the scrollbar are the controls.
On the bottom left there will be five similar sets of controls to control each 
induvidual graph such as "Display:<button>" which button will toggle that individual graph on/off. If <button> is ticked, the graph will be displayed.
"Color:<color>" which is just a button to show which color will be used to draw that graph (color is only available in Gtk2 version) and finally
"Filter:<filter-text>" which can be used to specify a display filter for that particular graph.

If filter-text is empty then all packets will be used to calculate the quantity for that graph. If filter-text is specified only those packets that match that display filter will be considered in the calculation of quantity.


To the right of the 5 graph controls there are four menus to control global aspects of the draw area and graphs.
The "Unit:" menu is used to control what to measure; "frames/tick", "bytes/tick" or "advanced..."

frames/tick  will measure the number of frames matching the (if specified) display filter for the graph in each measurement interval.

bytes/tick   will measure the total number of bytes in all frames matching the (if specified) display filter for the graph in each measurement interval.

advanced... see below


"Tick interval:" specifies what measurement intervals to use. The default is 1 second and means that the data will be counted over 1 second intervals.

"Pixels per tick:" specifies how many pixels wide each measurement interval will be in the drawing area. The default is 5 pixels per tick.

"Y-scale:" controls the max value for the y-axis. Default value is "auto" which means that ethereal will try to adjust the maxvalue automatically.



"advanced..."   If Unit:advanced... is selected the window will display two more controls for each of the five graphs.
One control will be a menu where the type of calculation can be selected from SUM,COUNT,MAX,MIN and AVG, and one control, textbox, where the name of a single display filter field can be specified.

The following restrictions apply to type and field combinations:
SUM: availabel for all types of integers.
COUNT: available for all field types.
MAX: available for all integer and relative time fields.
MIN: available for all integer and relative time fields.
AVG: available for all integer and relative time fields.

NOTE: due to the way this is implemented in ethereal there is a requirement that whatever field is specified in the textbox, that field MUST also be part of the filter for the graph or else the calculations will fail.

Example of advanced:
Display how NFS response time MAX/MIN/AVG changes over time:

Set first graph to   filter:nfs&&rpc.time Calc:MAX rpc.time
Set second graph to  filter:nfs&&rpc.time Calc:AVG rpc.time
Set third graph to   filter:nfs&&rpc.time Calc:MIN rpc.time


Example of advanced:
Display how the average packetsize from host a.b.c.d changes over time.

Set first graph to   filter:ip.addr==a.b.c.d&&frame.pkt_len  Calc:AVG frame.pkt_len


=item Tools:Statistics:SMB:RTT

Collect call/reply RTT data for SMB.  Data collected
is number of calls for each SMB command, MinRTT, MaxRTT and AvgRTT. 

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.



=head2 WINDOWS

=over 4

=item Main Window

The main window is split into three panes.  You can resize each pane using
a "thumb" at the right end of each divider line.  Below the panes is a
strip that shows the current filter and informational text.

=over 6

=item Top Pane

The top pane contains the list of network packets that you can scroll
through and select.  By default, the packet number, packet timestamp,
source and destination addresses, protocol, and description are
displayed for each packet; the I<Columns> page in the dialog box popped
up by I<Edit:Preferences> lets you change this (although, unfortunately,
you currently have to save the preferences, and exit and restart
Ethereal, for those changes to take effect).

If you click on the heading for a column, the display will be sorted by
that column; clicking on the heading again will reverse the sort order
for that column.

An effort is made to display information as high up the protocol stack
as possible, e.g. IP addresses are displayed for IP packets, but the
MAC layer address is displayed for unknown packet types.

The right mouse button can be used to pop up a menu of operations.

The middle mouse button can be used to mark a packet.

=item Middle Pane

The middle pane contains a I<protocol tree> for the currently-selected
packet.  The tree displays each field and its value in each protocol
header in the stack.  The right mouse button can be used to pop up a
menu of operations.

=item Bottom Pane

The lowest pane contains a hex dump of the actual packet data. 
Selecting a field in the I<protocol tree> highlights the corresponding
bytes in this section.

The right mouse button can be used to pop up a menu of operations.

=item Current Filter

A display filter can be entered into the strip at the bottom. 
A filter for HTTP, HTTPS, and DNS traffic might look like this:

  tcp.port == 80 || tcp.port == 443 || tcp.port == 53

Selecting the I<Filter:> button lets you choose from a list of named
filters that you can optionally save.  Pressing the Return or Enter
keys, or selecting the I<Apply> button, will cause the filter to be
applied to the current list of packets.  Selecting the I<Reset> button
clears the display filter so that all packets are displayed.

=back

=item Preferences

The I<Preferences> dialog lets you control various personal preferences
for the behavior of B<Ethereal>.

=over 6

=item Printing Preferences

The radio buttons at the top of the I<Printing> page allow you choose
between printing packets with the I<File:Print Packet> menu item as text
or PostScript, and sending the output directly to a command or saving it
to a file.  The I<Command:> text entry box, on UNIX-compatible systems,
is the command to send files to (usually B<lpr>), and the I<File:> entry
box lets you enter the name of the file you wish to save to. 
Additionally, you can select the I<File:> button to browse the file
system for a particular save file.

=item Column Preferences

The I<Columns> page lets you specify the number, title, and format
of each column in the packet list.

The I<Column title> entry is used to specify the title of the column
displayed at the top of the packet list.  The type of data that the column
displays can be specified using the I<Column format> option menu.
The row of buttons on the left perform the following actions:

=over 6

=item Add New

Adds a new column to the list.

=item Delete

Deletes the currently selected list item.

=item Up / Down

Moves the selected list item up or down one position.

=item OK

Currently has no effect.

=item Save

Saves the current column format as the default.

=item Cancel

Closes the dialog without making any changes.

=back

=item TCP Streams Preferences

The I<TCP Streams> page can be used to change the color of the text
displayed in the TCP stream window.  To change a color, simply select
an attribute from the "Set:" menu and use the color selector to get the
desired color.  The new text colors are displayed in a sample window.

=item User Interface Preferences

The I<User Interface> page is used to modify small aspects of the GUI to
your own personal taste:

=over 6

=item Scrollbars

The vertical scrollbars in the three panes can be set to be either on
the left or the right. 

=item Selection Bars

The selection bar in the packet list and protocol tree can have either a
"browse" or "select" behavior.  If the selection bar has a "browse"
behavior, the arrow keys will move an outline of the selection bar,
allowing you to browse the rest of the list or tree without changing the
selection until you press the space bar.  If the selection bar has a
"select" behavior, the arrow keys will move the selection bar and change
the selection to the new item in the packet list or protocol tree.

=item Tree Line Style

Trees can be drawn with no lines, solid lines, or dotted lines between
items, or can be drawn with "tab" headings.

=item Tree Expander Style

The expander item that can be clicked to show or hide items under a tree
item can be omitted (note that this will prevent you from changing
whether those items are shown or hidden!), or can be drawn as squares,
triangles, or circles.

=item Hex Display

The highlight method in the hex dump display for the selected protocol
item can be set to use either inverse video, or bold characters.

=item Save Window Position

If this item is selected, the position of the main Ethereal window will
be saved when Ethereal exits, and used when Ethereal is started again.

=item Save Window Size

If this item is selected, the size of the main Ethereal window will
be saved when Ethereal exits, and used when Ethereal is started again.

=item Fonts

The "Font..." button lets you select the font to be used for most text.

=item Colors

The "Colors..." button lets you select the colors to be used for instance
for the marked frames.

=back

=item Capture Preferences

The I<Capture> page lets you specify various parameters for capturing
live packet data; these are used the first time a capture is started.

The I<Interface:> combo box lets you specify the interface from which to
capture packet data, or the name of a FIFO from which to get the packet
data.  You can specify whether the interface is to be put in promiscuous
mode or not with the I<Capture packets in promiscuous mode> check box,
can specify that the display should be updated as packets are captured
with the I<Update list of packets in real time> check box, and can
specify whether in such a capture the packet list pane should scroll to
show the most recently captured packets with the I<Automatic scrolling
in live capture> check box.

=item Protocol Preferences

There are also pages for various protocols that Ethereal dissects,
controlling the way Ethereal handles those protocols.

=back

=item Edit Capture Filter List

=item Edit Display Filter List

=item Capture Filter

=item Display Filter

=item Read Filter

=item Search Filter

The I<Edit Capture Filter List> dialog lets you create, modify, and
delete capture filters, and the I<Edit Display Filter List> dialog lets
you create, modify, and delete display filters.

The I<Capture Filter> dialog lets you do all of the editing operations
listed, and also lets you choose or construct a filter to be used when
capturing packets.

The I<Display Filter> dialog lets you do all of the editing operations
listed, and also lets you choose or construct a filter to be used to
filter the current capture being viewed.

The I<Read Filter> dialog lets you do all of the editing operations
listed, and also lets you choose or construct a filter to be used to
as a read filter for a capture file you open.

The I<Search Filter> dialog lets you do all of the editing operations
listed, and also lets you choose or construct a filter expression to be
used in a find operation.

In all of those dialogs, the I<Filter name> entry specifies a
descriptive name for a filter, e.g.  B<Web and DNS traffic>.  The
I<Filter string> entry is the text that actually describes the filtering
action to take, as described above.The dialog buttons perform the
following actions:

=over 6

=item New

If there is text in the two entry boxes, creates a new associated list
item.

=item Change

Modifies the currently selected list item to match what's in the entry
boxes.

=item Copy

Makes a copy of the currently selected list item.

=item Delete

Deletes the currently selected list item.

=item Add Expression...

For display filter expressions, pops up a dialog box to allow you to
construct a filter expression to test a particular field; it offers
lists of field names, and, when appropriate, lists from which to select
tests to perform on the field and values with which to compare it.  In
that dialog box, the OK button will cause the filter expression you
constructed to be entered into the I<Filter string> entry at the current
cursor position.

=item OK

In the I<Capture Filter> dialog, closes the dialog box and makes the
filter in the I<Filter string> entry the filter in the I<Capture
Preferences> dialog.  In the I<Display Filter> dialog, closes the dialog
box and makes the filter in the I<Filter string> entry the current
display filter, and applies it to the current capture.  In the I<Read
Filter> dialog, closes the dialog box and makes the filter in the
I<Filter string> entry the filter in the I<Open Capture File> dialog. 
In the I<Search Filter> dialog, closes the dialog box and makes the
filter in the I<Filter string> entry the filter in the I<Find Frame>
dialog.

=item Apply

Makes the filter in the I<Filter string> entry the current display
filter, and applies it to the current capture.

=item Save

Saves the current filter list in F<$HOME/.ethereal/cfilters> on
UNIX-compatible systems, and F<%APPDATA%\Ethereal\cfilters> (or, if
%APPDATA% isn't defined,
F<%USERPROFILE%\Application Data\Ethereal\cfilters>)
on Windows systems, if the list of filters being edited is the list of
capture filters, or in F<$HOME/.ethereal/dfilters> on UNIX-compatible
systems, and F<%APPDATA%\Ethereal\dfilters> (or, if %APPDATA% isn't
defined, F<%USERPROFILE%\Application Data\Ethereal\dfilters>) on Windows
systems, if the list of filters being edited is the list of display
filters.

=item Close

Closes the dialog without doing anything with the filter in the I<Filter
string> entry.

=back

=item Capture Options

The I<Capture Options> dialog lets you specify various parameters for
capturing live packet data.

The I<Interface:> field lets you specify the interface from which to
capture packet data or a command from which to get the packet data via a
pipe.

The I<Limit each packet to ... bytes> check box and field lets you
specify a maximum number of bytes per packet to capture and save; if the
check box is not checked, the limit will be 65535 bytes.

The I<Capture packets in promiscuous mode> check box lets you specify
whether the interface should be put into promiscuous mode when
capturing.

The I<Filter:> entry lets you specify the capture filter using a
tcpdump-style filter string as described above.

The I<File:> entry lets you specify the file into which captured packets
should be saved, as in the I<Printer Options> dialog above.  If not
specified, the captured packets will be saved in a temporary file; you
can save those packets to a file with the I<File:Save As> menu item.

The I<Use ring buffer> check box lets you specify that the capture
should be done in "ring buffer" mode; the I<Number of files> field
lets you specify the number of files in the ring buffer.

The I<Update list of packets in real time> check box lets you specify
whether the display should be updated as packets are captured and, if
you specify that, the I<Automatic scrolling in live capture> check box
lets you specify the packet list pane should automatically scroll to
show the most recently captured packets as new packets arrive.

The I<Stop capture after ... packet(s) captured> check box and field let
you specify that Ethereal should stop capturing after having captured
some number of packets; if the check box is not checked, Ethereal will
not stop capturing at some fixed number of captured packets.

If "ring buffer" mode is not specified, the I<Stop capture after ...
kilobyte(s) captured> check box and field let you specify that Ethereal
should stop capturing after the the file to which captured packets are
being saved grows as large as or larger than some specified number of
kilobytes (where a kilobyte is 1000 bytes, not 1024 bytes).  If the
check box is not checked, Ethereal will not stop capturing at some
capture file size (although the operating system on which Ethereal is
running, or the available disk space, may still limit the maximum size
of a capture file).

If "ring buffer" mode is specified, that field becomes the I<Rotate
capture file very ...  kilobyte(s)> field, and specifies the number
of kilobytes at which to start writing to a new ring buffer file; the
check box is forced to be checked, as "ring buffer" mode requires a file
size to be specified.

The I<Stop capture after ...  second(s)> check box and field let you
specify that Ethereal should stop capturing after it has been capturing
for some number of seconds; if the check box is not checked, Ethereal
will not stop capturing after some fixed time has elapsed.

The I<Enable MAC name resolution>, I<Enable network name resolution> and
I<Enable transport name resolution> check boxes let you specify whether
MAC addresses, network addresses, and transport-layer port numbers
should be translated to names.

=item Display Options

The I<Display Options> dialog lets you specify the format of the time
stamp in the packet list.  You can select "Time of day" for absolute
time stamps, "Date and time of day" for absolute time stamps with the
date, "Seconds since beginning of capture" for relative time stamps, or
"Seconds since previous frame" for delta time stamps.  You can also
specify whether, when the display is updated as packets are captured,
the list should automatically scroll to show the most recently captured
packets or not and whether addresses or port numbers should be
translated to names in the display on a MAC, network and transport layer
basis.

=item Plugins

The I<Plugins> dialog lets you view the dissector plugin modules
available on your system.

The I<Plugins List> shows the name and version of each dissector plugin
module found on your system.  The plugins are searched in the following
directories: the F<lib/ethereal/plugins/$VERSION> directory under the
main installation directory (for example,
F</usr/local/lib/ethereal/plugins/$VERSION>),
F</usr/lib/ethereal/plugins/$VERSION>,
F</usr/local/lib/ethereal/plugins/$VERSION>, and
F<$HOME/.ethereal/plugins> on UNIX-compatible systems, and in the
F<plugins\$VERSION> directory under the main installation directory (for
example, F<C:\Program Files\Ethereal\plugins\$VERSION>) and
F<%APPDATA%\Ethereal\plugins\$VERSION> (or, if %APPDATA% isn't defined,
F<%USERPROFILE%\Application Data\Ethereal\plugins\$VERSION>) on Windows
systems; $VERSION is the version number of the plugin interface, which
is typically the version number of Ethereal.  Note that a dissector
plugin module may support more than one protocol; there is not
necessarily a one-to-one correspondence between dissector plugin modules
and protocols.  Protocols supported by a dissector plugin module are
enabled and disabled using the I<Edit:Protocols> dialog box, just as
protocols built into Ethereal are.

=head1 CAPTURE FILTER SYNTAX

See manual page of tcpdump(8).

=head1 DISPLAY FILTER SYNTAX

Display filters help you remove the noise from a packet trace and let
you see only the packets that interest you.  If a packet meets the
requirements expressed in your display filter, then it is displayed in
the list of packets.  Display filters let you compare the fields within
a protocol against a specific value, compare fields against fields, and
to check the existence of specified fields or protocols.

The simplest display filter allows you to check for the existence of a
protocol or field.  If you want to see all packets which contain the IPX
protocol, the filter would be "ipx".  (Without the quotation marks) To
see all packets that contain a Token-Ring RIF field, use "tr.rif".

Fields can also be compared against values.  The comparison operators
can be expressed either through C-like symbols, or through English-like
abbreviations:

    eq, ==    Equal
    ne, !=    Not equal
    gt, >     Greater than
    lt, <     Less Than
    ge, >=    Greater than or Equal to
    le, <=    Less than or Equal to

Furthermore, each protocol field is typed. The types are:

    Unsigned integer (either 8-bit, 16-bit, 24-bit, or 32-bit)
    Signed integer (either 8-bit, 16-bit, 24-bit, or 32-bit)
    Boolean
    Ethernet address (6 bytes)
    Byte string (n-number of bytes)
    IPv4 address
    IPv6 address
    IPX network number
    String (text)
    Double-precision floating point number

An integer may be expressed in decimal, octal, or hexadecimal notation. 
The following three display filters are equivalent:

    frame.pkt_len > 10
    frame.pkt_len > 012
    frame.pkt_len > 0xa

Boolean values are either true or false.  In a display filter expression
testing the value of a Boolean field, "true" is expressed as 1 or any
other non-zero value, and "false" is expressed as zero.  For example, a
token-ring packet's source route field is boolean.  To find any
source-routed packets, a display filter would be:

    tr.sr == 1

Non source-routed packets can be found with:

    tr.sr == 0

Ethernet addresses, as well as a string of bytes, are represented in hex
digits.  The hex digits may be separated by colons, periods, or hyphens:

    fddi.dst eq ff:ff:ff:ff:ff:ff
    ipx.srcnode == 0.0.0.0.0.1
    eth.src == aa-aa-aa-aa-aa-aa

If a string of bytes contains only one byte, then it is represented as
an unsigned integer.  That is, if you are testing for hex value 'ff' in
a one-byte byte-string, you must compare it agains '0xff' and not 'ff'. 

IPv4 addresses can be represented in either dotted decimal notation, or
by using the hostname:

    ip.dst eq www.mit.edu
    ip.src == 192.168.1.1

IPv4 addresses can be compared with the same logical relations as numbers:
eq, ne, gt, ge, lt, and le.  The IPv4 address is stored in host order,
so you do not have to worry about how the endianness of an IPv4 address
when using it in a display filter.

Classless InterDomain Routing (CIDR) notation can be used to test if an
IPv4 address is in a certain subnet.  For example, this display filter
will find all packets in the 129.111 Class-B network:

    ip.addr == 129.111.0.0/16

Remember, the number after the slash represents the number of bits used
to represent the network.  CIDR notation can also be used with
hostnames, in this example of finding IP addresses on the same Class C
network as 'sneezy':

    ip.addr eq sneezy/24

The CIDR notation can only be used on IP addresses or hostnames, not in
variable names.  So, a display filter like "ip.src/24 == ip.dst/24" is
not valid.  (yet)

IPX networks are represented by unsigned 32-bit integers.  Most likely
you will be using hexadecimal when testing for IPX network values:

    ipx.srcnet == 0xc0a82c00

A slice operator also exists.  You can check the substring
(byte-string) of any protocol or field.  For example, you can filter on
the vendor portion of an ethernet address (the first three bytes) like
this:

    eth.src[0:3] == 00:00:83

If the length of your byte-slice is only one byte, then it is still
represented in hex, but without the preceding "0x": 

    llc[3] == aa

You can use the slice operator on a protocol name, too.  And
remember, the "frame" protocol encompasses the entire packet, allowing
you to look at the nth byte of a packet regardless of its frame type
(Ethernet, token-ring, etc.).

    token[0:5] ne 0.0.0.1.1
    ipx[0:2] == ff:ff
    llc[3:1] eq 0xaa

The following syntax governs slices:

	[i:j]	i = start_offset, j = length
	[i-j]	i = start_offet, j = end_offset, inclusive.
	[i]	i = start_offset, length = 1
	[:j]	start_offset = 0, length = j
	[i:]	start_offset = i, end_offset = end_of_field

Offsets and lengths can be negative, in which case they indicate the
offset from the B<end> of the field.  Here's how to check the last 4
bytes of a frame:

    frame[-4:4] == 0.1.2.3

or

    frame[-4:] == 0.1.2.3

You can create complex concatenations of slices using the comma operator:

	field[1,3-5,9:] == 01:03:04:05:09:0a:0b

All the above tests can be combined together with logical expressions. 
These too are expressable in C-like syntax or with English-like
abbreviations:

    and, &&   Logical AND
    or, ||    Logical OR
    not, !    Logical NOT

Expressions can be grouped by parentheses as well.  The following are
all valid display filter expression:

    tcp.port == 80 and ip.src == 192.168.2.1
    not llc
    (ipx.srcnet == 0xbad && ipx.srnode == 0.0.0.0.0.1) || ip
    tr.dst[0:3] == 0.6.29 xor tr.src[0:3] == 0.6.29

A special caveat must be given regarding fields that occur more than
once per packet.  "ip.addr" occurs twice per IP packet, once for the
source address, and once for the destination address.  Likewise,
tr.rif.ring fields can occur more than once per packet.  The following
two expressions are not equivalent:

        ip.addr ne 192.168.4.1
    not ip.addr eq 192.168.4.1

The first filter says "show me IP packets where an ip.addr exists that
does not equal 192.168.4.1".  That is, as long as one ip.addr in the
packet does not equal 192.168.44.1, the packet passes the display
filter.  The second filter "don't show me any packets that have at least
one ip.addr field equal to 192.168.4.1".  If one ip.addr is 192.168.4.1,
the packet does not pass.  If B<neither> ip.addr fields is 192.168.4.1,
then the packet passes.

It is easy to think of the 'ne' and 'eq' operators as having an implict
"exists" modifier when dealing with multiply-recurring fields.  "ip.addr
ne 192.168.4.1" can be thought of as "there exists an ip.addr that does
not equal 192.168.4.1".

Be careful with multiply-recurring fields; they can be confusing.

Care must also be taken when using the display filter to remove noise
from the packet trace. If you want to e.g. filter out all IP multicast
packets to address 224.1.2.3, then using:

    ip.dst ne 224.1.2.3

may be too restrictive. Filtering with "ip.dst" selects only those
B<IP> packets that satisfy the rule. Any other packets, including all
non-IP packets, will not displayed. For displaying also the non-IP
packets, you can use one of the following two expressions:

    not ip or ip.dst ne 224.1.2.3
    not ip.addr eq 224.1.2.3

The first filter uses "not ip" to include all non-IP packets and then
lets "ip.dst ne 224.1.2.3" to filter out the unwanted IP packets. The
second filter has already been explained above where filtering with
multiply occuring fields was discussed.

The following is a table of protocol and protocol fields that are
filterable in B<Ethereal>.  The abbreviation of the protocol or field is
given.  This abbreviation is what you use in the display filter.  The
type of the field is also given.

=insert_dfilter_table

=head1 FILES

The F<ethereal.conf> 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, 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 file contains 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<Ethereal>'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.

Note that whenever the preferences are saved by using the I<Save> button
in the I<Edit:Preferences> dialog box, your personal preferences file
will be overwritten with the new settings, destroying any comments that
were in the file.

The 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 F<ethers> file, the F<$HOME/.ethereal/ethers> file on
UNIX-compatible systems, and the F<%APPDATA%\Ethereal\ethers> file (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 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 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 F<ipxnets> file, the F<$HOME/.ethereal/ipxnets> file on
UNIX-compatible systems, and the F<%APPDATA%\Ethereal\ipxnets> file (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 ipxnets file.

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

=head1 SEE ALSO

I<tethereal(1)>, I<editcap(1)>, I<tcpdump(8)>, I<pcap(3)>

=head1 NOTES

The latest version of B<Ethereal> can be found at
B<http://www.ethereal.com>.

=head1 AUTHORS

  Original Author
  -------- ------
  Gerald Combs  <gerald[AT]ethereal.com>


  Contributors
  ------------
  Gilbert Ramirez          <gram[AT]alumni.rice.edu>
  Hannes R. Boehm          <hannes[AT]boehm.org>
  Mike Hall                <mike [AT] hallzone.net>
  Bobo Rajec               <bobo[AT]bsp-consulting.sk>
  Laurent Deniel           <laurent.deniel[AT]free.fr>
  Don Lafontaine           <lafont02[AT]cn.ca>
  Guy Harris               <guy[AT]alum.mit.edu>
  Simon Wilkinson          <sxw[AT]dcs.ed.ac.uk>
  Joerg Mayer              <jmayer[AT]loplof.de>
  Martin Maciaszek         <fastjack[AT]i-s-o.net>
  Didier Jorand            <Didier.Jorand[AT]alcatel.fr>
  Jun-ichiro itojun Hagino <itojun[AT]itojun.org>
  Richard Sharpe           <sharpe[AT]ns.aus.com>
  John McDermott           <jjm[AT]jkintl.com> 
  Jeff Jahr                <jjahr[AT]shastanets.com>
  Brad Robel-Forrest       <bradr[AT]watchguard.com>
  Ashok Narayanan          <ashokn[AT]cisco.com>
  Aaron Hillegass          <aaron[AT]classmax.com>
  Jason Lango              <jal[AT]netapp.com>
  Johan Feyaerts           <Johan.Feyaerts[AT]siemens.atea.be>
  Olivier Abad             <oabad[AT]noos.fr>
  Thierry Andry            <Thierry.Andry[AT]advalvas.be>
  Jeff Foster              <jfoste[AT]woodward.com>
  Peter Torvals            <petertv[AT]xoommail.com>
  Christophe Tronche       <ch.tronche[AT]computer.org>
  Nathan Neulinger         <nneul[AT]umr.edu>
  Tomislav Vujec           <tvujec[AT]carnet.hr>
  Kojak                    <kojak[AT]bigwig.net>
  Uwe Girlich              <Uwe.Girlich[AT]philosys.de>
  Warren Young             <tangent[AT]mail.com>
  Heikki Vatiainen         <hessu[AT]cs.tut.fi>
  Greg Hankins             <gregh[AT]twoguys.org>
  Jerry Talkington         <jerryt[AT]netapp.com>
  Dave Chapeskie           <dchapes[AT]ddm.on.ca>
  James Coe                <jammer[AT]cin.net>
  Bert Driehuis            <driehuis[AT]playbeing.org>
  Stuart Stanley           <stuarts[AT]mxmail.net>
  John Thomes              <john[AT]ensemblecom.com>
  Laurent Cazalet          <laurent.cazalet[AT]mailclub.net>
  Thomas Parvais           <thomas.parvais[AT]advalvas.be>
  Gerrit Gehnen            <G.Gehnen[AT]atrie.de>
  Craig Newell             <craign[AT]cheque.uq.edu.au>
  Ed Meaney                <emeaney[AT]cisco.com>
  Dietmar Petras           <DPetras[AT]ELSA.de> 
  Fred Reimer              <fwr[AT]ga.prestige.net>
  Florian Lohoff           <flo[AT]rfc822.org>
  Jochen Friedrich         <jochen+ethereal[AT]scram.de>
  Paul Welchinski          <paul.welchinski[AT]telusplanet.net>
  Doug Nazar               <nazard[AT]dragoninc.on.ca>
  Andreas Sikkema          <andreas.sikkema[AT]philips.com>
  Mark Muhlestein          <mmm[AT]netapp.com>
  Graham Bloice            <graham.bloice[AT]trihedral.com>
  Ralf Schneider           <ralf.schneider[AT]alcatel.se>
  Yaniv Kaul               <ykaul[AT]netvision.net.il>
  Paul Ionescu             <paul[AT]acorp.ro>
  Mark Burton              <markb[AT]ordern.com>
  Stefan Raab              <sraab[AT]cisco.com>
  Mark Clayton             <clayton[AT]shore.net>
  Michael Rozhavsky        <mike[AT]tochna.technion.ac.il>
  Dug Song                 <dugsong[AT]monkey.org>
  Michael Tuexen           <Michael.Tuexen [AT] siemens.com>
  Bruce Korb               <bkorb[AT]sco.com>
  Jose Pedro Oliveira      <jpo[AT]di.uminho.pt>
  David Frascone           <dave[AT]frascone.com>
  Peter Kjellerstedt       <pkj[AT]axis.com>
  Phil Techau              <phil_t[AT]altavista.net>
  Wes Hardaker             <wjhardaker[AT]ucdavis.edu>
  Robert Tsai              <rtsai[AT]netapp.com>
  Craig Metz               <cmetz[AT]inner.net>
  Per Flock                <per.flock[AT]axis.com>
  Jack Keane               <jkeane[AT]OpenReach.com>
  Brian Wellington         <bwelling[AT]xbill.org>
  Santeri Paavolainen      <santtu[AT]ssh.com>
  Ulrich Kiermayr          <uk[AT]ap.univie.ac.at>
  Neil Hunter              <neil.hunter[AT]energis-squared.com>
  Ralf Holzer              <ralf[AT]well.com>
  Craig Rodrigues          <rodrigc [AT] attbi.com>
  Ed Warnicke              <hagbard[AT]physics.rutgers.edu>
  Johan Jorgensen          <johan.jorgensen[AT]axis.com>
  Frank Singleton          <frank.singleton[AT]ericsson.com>
  Kevin Shi                <techishi[AT]ms22.hinet.net>
  Mike Frisch              <mfrisch[AT]isurfer.ca>
  Burke Lau                <burke_lau[AT]agilent.com>
  Martti Kuparinen         <martti.kuparinen[AT]iki.fi>
  David Hampton            <dhampton[AT]mac.com>
  Kent Engström            <kent[AT]unit.liu.se>
  Ronnie Sahlberg          <sahlberg[AT]optushome.com.au>
  Borosa Tomislav          <tomislav.borosa[AT]SIEMENS.HR>
  Alexandre P. Ferreira    <alexandref[AT]tcoip.com.br>
  Simharajan Srishylam     <Simharajan.Srishylam[AT]netapp.com>
  Greg Kilfoyle            <gregk[AT]redback.com>
  James E. Flemer          <jflemer[AT]acm.jhu.edu>
  Peter Lei                <peterlei[AT]cisco.com>
  Thomas Gimpel            <thomas.gimpel[AT]ferrari.de>
  Albert Chin              <china[AT]thewrittenword.com>
  Charles Levert           <charles[AT]comm.polymtl.ca>
  Todd Sabin               <tas[AT]webspan.net>
  Eduardo Pérez Ureta      <eperez[AT]dei.inf.uc3m.es>
  Martin Thomas            <martin_a_thomas[AT]yahoo.com>
  Hartmut Mueller          <hartmut[AT]wendolene.ping.de>
  Michal Melerowicz        <Michal.Melerowicz[AT]nokia.com>
  Hannes Gredler           <hannes[AT]juniper.net>
  Inoue                    <inoue[AT]ainet.or.jp>
  Olivier Biot             <Olivier.Biot[AT]siemens.com>
  Patrick Wolfe            <pjw[AT]zocalo.cellular.ameritech.com>
  Martin Held              <Martin.Held[AT]icn.siemens.de>
  Riaan Swart              <rswart[AT]cs.sun.ac.za>
  Christian Lacunza        <celacunza[AT]gmx.net>
  Scott Renfro             <scott[AT]renfro.org>
  Juan Toledo              <toledo[AT]users.sourceforge.net>
  Jean-Christian Pennetier <jeanchristian.pennetier[AT]rd.francetelecom.fr>
  Jian Yu                  <bgp4news[AT]yahoo.com>
  Eran Mann                <emann[AT]opticalaccess.com>
  Andy Hood                <ahood[AT]westpac.com.au>
  Randy McEoin             <rmceoin[AT]pe.net>
  Edgar Iglesias           <edgar.iglesias[AT]axis.com>
  Martina Obermeier        <Martina.Obermeier[AT]icn.siemens.de>
  Javier Achirica          <achirica[AT]ttd.net>
  B. Johannessen           <bob[AT]havoq.com>
  Thierry Pelle            <thierry.pelle[AT]rd.francetelecom.fr>
  Francisco Javier Cabello <fjcabello[AT]vtools.es>
  Laurent Rabret           <laurent.rabret[AT]rd.francetelecom.fr>
  nuf si                   <gnippiks[AT]yahoo.com>
  Jeff Morriss             <jeff.morriss[AT]ulticom.com>
  Aamer Akhter             <aakhter[AT]cisco.com>
  Pekka Savola             <pekkas[AT]netcore.fi>
  David Eisner             <cradle[AT]Glue.umd.edu>
  Steve Dickson            <steved[AT]talarian.com>
  Markus Seehofer          <mseehofe[AT]nt.hirschmann.de>
  Lee Berger               <lberger[AT]roy.org>
  Motonori Shindo          <mshindo[AT]mshindo.net>
  Terje Krogdahl           <tekr[AT]nextra.com>
  Jean-Francois Mule       <jfm[AT]cablelabs.com>
  Thomas Wittwer           <thomas.wittwer[AT]iclip.ch>
  Matthias Nyffenegger     <matthias.nyffenegger[AT]iclip.ch>
  Palle Lyckegaard         <Palle[AT]lyckegaard.dk>
  Nicolas Balkota          <balkota[AT]mac.com>
  Tom Uijldert             <Tom.Uijldert[AT]cmg.nl>
  Akira Endoh              <endoh[AT]netmarks.co.jp>
  Graeme Hewson            <graeme.hewson[AT]oracle.com>
  Pasi Eronen              <pasi.eronen[at]nixu.com>
  Georg von Zezschwitz     <gvz[AT]2scale.net>
  Steffen Weinreich        <steve[AT]weinreich.org>
  Marc Milgram             <ethereal[AT]mmilgram.NOSPAMmail.net>
  Gordon McKinney          <gordon[AT]night-ray.com>
  Tim Farley               <tfarley[AT]iss.net>
  Daniel Thompson          <daniel.thompson[AT]st.com>
  Chris Jepeway            <thai-dragon[AT]eleven29.com>
  Pavel Novotny            <Pavel.Novotny[AT]icn.siemens.de>
  Shinsuke Suzuki          <suz[AT]kame.net>
  Andrew C. Feren          <aferen[AT]cetacean.com>
  Tomas Kukosa             <tomas.kukosa [AT] siemens.com>
  Andreas Stockmeier       <a.stockmeier[AT]avm.de>
  Pekka Nikander           <pekka.nikander[AT]nomadiclab.com>
  Hamish Moffatt           <hamish[AT]cloud.net.au>
  Kazushi Sugyo            <k-sugyou[AT]nwsl.mesh.ad.jp>
  Tim Potter               <tpot[AT]samba.org>
  Raghu Angadi             <rangadi[AT]inktomi.com>
  Taisuke Sasaki           <sasaki[AT]soft.net.fujitsu.co.jp>
  Tim Newsham              <newsham[AT]lava.net>
  Tom Nisbet               <Tnisbet[AT]VisualNetworks.com>
  Darren New               <dnew[AT]san.rr.com>
  Pavel Mores              <pvl[AT]uh.cz>
  Bernd Becker             <bb[AT]bernd-becker.de>
  Heinz Prantner           <Heinz.Prantner[AT]radisys.com>
  Irfan Khan               <ikhan[AT]qualcomm.com>
  Jayaram V.R              <vjayar[AT]cisco.com>
  Dinesh Dutt              <ddutt[AT]cisco.com>
  Nagarjuna Venna          <nvenna[AT]Brixnet.com>
  Jirka Novak              <j.novak[AT]netsystem.cz>
  Ricardo Barroetaveña     <rbarroetavena[AT]veufort.com>
  Alan Harrison            <alanharrison[AT]mail.com>
  Mike Frantzen            <frantzen[AT]w4g.org>
  Charlie Duke             <cduke[AT]fvc.com>
  Alfred Arnold            <Alfred.Arnold[AT]elsa.de>
  Dermot Bradley           <dermot.bradley[AT]openwave.com>
  Adam Sulmicki            <adam[AT]cfar.umd.edu>
  Kari Tiirikainen         <kari.tiirikainen[AT]nokia.com>
  John Mackenzie           <John.A.Mackenzie[AT]t-online.de>
  Peter Valchev            <pvalchev[AT]openbsd.org>
  Alex Ruzin               <alexr[AT]nbase.co.il>
  Jouni Malinen            <jkmaline[AT]cc.hut.fi>
  Paul E. Erkkila          <pee[AT]erkkila.org>
  Jakob Schlyter           <jakob[AT]crt.se>
  Jim Sienicki             <sienicki[AT]issanni.com>
  Steven French            <sfrench[AT]us.ibm.com>
  Diana Eichert            <deicher[AT]sandia.gov>
  Blair Cooper             <blair[AT]teamon.com>
  Kikuchi Ayamura          <ayamura[AT]ayamura.org>
  Didier Gautheron         <dgautheron[AT]magic.fr>
  Phil Williams            <csypbw[AT]comp.leeds.ac.uk>
  Kevin Humphries          <khumphries[AT]networld.com>
  Erik Nordström           <erik.nordstrom[AT]it.uu.se>
  Devin Heitmueller        <dheitmueller[AT]netilla.com>
  Chenjiang Hu             <chu[AT]chiaro.com>
  Kan Sasaki               <sasaki[AT]fcc.ad.jp>
  Stefan Wenk              <stefan.wenk[AT]gmx.at>
  Ruud Linders             <ruud[AT]lucent.com>
  Andrew Esh               <Andrew.Esh[AT]tricord.com>
  Greg Morris              <GMORRIS[AT]novell.com>
  Dirk Steinberg           <dws[AT]dirksteinberg.de>
  Kari Heikkila            <kari.o.heikkila[AT]nokia.com>
  Olivier Dreux            <Olivier.Dreux[AT]alcatel.fr>
  Michael Stiller          <ms[AT]2scale.net>
  Antti Tuominen           <ajtuomin[AT]tml.hut.fi>
  Martin Gignac            <lmcgign[AT]mobilitylab.net>
  John Wells               <wells[AT]ieee.org>
  Loic Tortay              <tortay[AT]cc.in2p3.fr>
  Steve Housley            <Steve_Housley[AT]eur.3com.com>
  Peter Hawkins            <peter[AT]hawkins.emu.id.au>
  Bill Fumerola            <billf[AT]FreeBSD.org>
  Chris Waters             <chris[AT]waters.co.nz>
  Solomon Peachy           <pizza[AT]shaftnet.org>
  Jaime Fournier           <jafour1[AT]yahoo.com>
  Markus Steinmann         <ms[AT]seh.de>
  Tsutomu Mieno            <iitom[AT]utouto.com>
  Yasuhiro Shirasaki       <yasuhiro[AT]gnome.gr.jp>
  Anand V. Narwani         <anarwani[AT]cisco.com>
  Christopher K. St. John  <cks[AT]distributopia.com>
  Nix                      <nix[AT]esperi.demon.co.uk>
  Liviu Daia               <Liviu.Daia[AT]imar.ro>
  Richard Urwin            <rurwin[AT]schenck.co.uk>
  Prabhakar Krishnan       <Prabhakar.Krishnan[AT]netapp.com>
  Jim McDonough            <jmcd[AT]us.ibm.com>
  Sergei Shokhor           <sshokhor[AT]uroam.com>
  Hidetaka Ogawa           <ogawa[AT]bs2.qnes.nec.co.jp>
  Jan Kratochvil           <short[AT]ucw.cz>
  Alfred Koebler           <ak[AT]icon-sult.de>
  Vassilii Khachaturov     <Vassilii.Khachaturov[AT]comverse.com>
  Bill Studenmund          <wrstuden[AT]wasabisystems.com>
  Brian Bruns              <camber[AT]ais.org>
  Flavio Poletti           <flavio[AT]polettix.it>
  Marcus Haebler           <haeblerm[AT]yahoo.com>
  Ulf Lamping              <ulf.lamping[AT]web.de>
  Matthew Smart            <smart[AT]monkey.org>
  Luke Howard              <lukeh[AT]au.padl.com>
  PC Drew                  <drewpc[AT]ibsncentral.com>
  Renzo Tomas              <renzo.toma [AT] xs4all.nl>
  Clive A. Stubbings       <eth[AT]vjet.demon.co.uk>
  Steve Langasek           <vorlon [AT] netexpress.net>
  Brad Hards               <bhards[AT]bigpond.net.au>
  cjs 2895                 <cjs2895[AT]hotmail.com>
  Lutz Jaenicke            <Lutz.Jaenicke [AT] aet.TU-Cottbus.DE>
  Senthil Kumar Nagappan   <sknagappan [AT] yahoo.com>
  Jason House              <jhouse [AT] mitre.org>
  Peter Fales              <psfales [AT] lucent.com>
  Fritz Budiyanto          <fritzb88 [AT] yahoo.com>
  Jean-Baptiste Marchand   <Jean-Baptiste.Marchand [AT] hsc.fr>
  Andreas Trauer           <andreas.trauer [AT] siemens.com>
  Ronald Henderson         <Ronald.Henderson [AT] CognicaseUSA.com>
  Brian Ginsbach           <ginsbach [AT] cray.com>
  Dave Richards            <d_m_richards [AT] attbi.com>
  Martin Regner            <martin.regner [AT] chello.se>
  Jason Greene             <jason [AT] inetgurus.net>
  Marco Molteni            <mmolteni [AT] cisco.com>
  James Harris             <jharris [AT] fourhorsemen.org>
  rmkml                    <rmkml [AT] wanadoo.fr>
  Anders Broman            <a.broman [AT] telia.com>
  Christian Falckenberg    <christian.falckenberg [AT] nortelnetworks.com>
  Huagang Xie              <xie [AT] lids.org>
  cjs 2895                 <cjs2895 [AT] hotmail.com>
  Pasi Kovanen             <Pasi.Kovanen [AT] tahoenetworks.fi>
  Teemu Rinta-aho          <teemu.rinta-aho [AT] nomadiclab.com>
  Martijn Schipper         <martijn.schipper [AT] intersil.com>
  Wayne Parrott            <wayne_p [AT] pacific.net.au>
  Laurent Meyer            <laurent.meyer [AT] thales-avionics.com>
  Pavel Roskin             <proski [AT] gnu.org>
  Georgi Guninski          <guninski [AT] guninski.com>
  Jason Copenhaver         <jcopenha [AT] typedef.org>
  Markus Friedl            <markus [AT] openbsd.org>

Alain Magloire <alainm[AT]rcsm.ece.mcgill.ca> was kind enough to give his
permission to use his version of snprintf.c.

Dan Lasley <dlasley[AT]promus.com> gave permission for his dumpit() hex-dump
routine to be used.

Mattia Cazzola <mattiac[AT]alinet.it> provided a patch to the hex dump
display routine.

We use the exception module from Kazlib, a C library written by
Kaz Kylheku <kaz[AT]ashi.footprints.net>. Thanks goes to him for his
well-written library. The Kazlib home page can be found at
http://users.footprints.net/~kaz/kazlib.html