3 wireshark-filter - Wireshark filter syntax and reference
7 B<wireshark> [other options]
8 S<[ B<-R> "filter expression" ]>
10 B<tshark> [other options]
11 S<[ B<-R> "filter expression" ]>
15 B<Wireshark> and B<TShark> share a powerful filter engine that helps remove
16 the noise from a packet trace and lets you see only the packets that interest
17 you. If a packet meets the requirements expressed in your filter, then it
18 is displayed in the list of packets. Display filters let you compare the
19 fields within a protocol against a specific value, compare fields against
20 fields, and check the existence of specified fields or protocols.
22 Filters are also used by other features such as statistics generation and
23 packet list colorization (the latter is only available to B<Wireshark>). This
24 manual page describes their syntax and provides a comprehensive reference of
29 =head2 Check whether a field or protocol exists
31 The simplest filter allows you to check for the existence of a protocol or
32 field. If you want to see all packets which contain the IP protocol, the
33 filter would be "ip" (without the quotation marks). To see all packets
34 that contain a Token-Ring RIF field, use "tr.rif".
36 Think of a protocol or field in a filter as implicitly having the "exists"
39 Note: all protocol and field names that are available in B<Wireshark> and
40 B<TShark> filters are listed in the comprehensive B<FILTER PROTOCOL
41 REFERENCE> (see below).
43 =head2 Comparison operators
45 Fields can also be compared against values. The comparison operators
46 can be expressed either through English-like abbreviations or through
53 ge, >= Greater than or Equal to
54 le, <= Less than or Equal to
56 =head2 Search and match operators
58 Additional operators exist expressed only in English, not C-like syntax:
60 contains Does the protocol, field or slice contain a value
61 matches Does the protocol or text string match the given Perl
64 The "contains" operator allows a filter to search for a sequence of
65 characters, expressed as a string (quoted or unquoted), or bytes,
66 expressed as a byte array. For example, to search for a given HTTP
67 URL in a capture, the following filter can be used:
69 http contains "http://www.wireshark.org"
71 The "contains" operator cannot be used on atomic fields,
72 such as numbers or IP addresses.
74 The "matches" operator allows a filter to apply to a specified
75 Perl-compatible regular expression (PCRE). The "matches" operator is only
76 implemented for protocols and for protocol fields with a text string
77 representation. For example, to search for a given WAP WSP User-Agent,
80 wsp.user_agent matches "(?i)cldc"
82 This example shows an interesting PCRE feature: pattern match options have to
83 be specified with the B<(?>optionB<)> construct. For instance, B<(?i)> performs
84 a case-insensitive pattern match. More information on PCRE can be found in the
85 pcrepattern(3) man page (Perl Regular Expressions are explained in
86 L<http://www.perldoc.com/perl5.8.0/pod/perlre.html>).
88 Note: the "matches" operator is only available if B<Wireshark> or B<TShark>
89 have been compiled with the PCRE library. This can be checked by running:
94 or selecting the "About Wireshark" item from the "Help" menu in B<Wireshark>.
98 The filter language has the following functions:
100 upper(string-field) - converts a string field to uppercase
101 lower(string-field) - converts a string field to lowercase
103 upper() and lower() are useful for performing case-insensitive string
104 comparisons. For example:
106 upper(ncp.nds_stream_name) contains "MACRO"
107 lower(mount.dump.hostname) == "angel"
109 =head2 Protocol field types
111 Each protocol field is typed. The types are:
113 Unsigned integer (8-bit, 16-bit, 24-bit, or 32-bit)
114 Signed integer (8-bit, 16-bit, 24-bit, or 32-bit)
116 Ethernet address (6 bytes)
122 Double-precision floating point number
124 An integer may be expressed in decimal, octal, or hexadecimal notation.
125 The following three display filters are equivalent:
131 Boolean values are either true or false. In a display filter expression
132 testing the value of a Boolean field, "true" is expressed as 1 or any
133 other non-zero value, and "false" is expressed as zero. For example, a
134 token-ring packet's source route field is Boolean. To find any
135 source-routed packets, a display filter would be:
139 Non source-routed packets can be found with:
143 Ethernet addresses and byte arrays are represented by hex
144 digits. The hex digits may be separated by colons, periods, or hyphens:
146 eth.dst eq ff:ff:ff:ff:ff:ff
148 fddi.src == aa-aa-aa-aa-aa-aa
151 IPv4 addresses can be represented in either dotted decimal notation or
152 by using the hostname:
154 ip.dst eq www.mit.edu
155 ip.src == 192.168.1.1
157 IPv4 addresses can be compared with the same logical relations as numbers:
158 eq, ne, gt, ge, lt, and le. The IPv4 address is stored in host order,
159 so you do not have to worry about the endianness of an IPv4 address
160 when using it in a display filter.
162 Classless InterDomain Routing (CIDR) notation can be used to test if an
163 IPv4 address is in a certain subnet. For example, this display filter
164 will find all packets in the 129.111 Class-B network:
166 ip.addr == 129.111.0.0/16
168 Remember, the number after the slash represents the number of bits used
169 to represent the network. CIDR notation can also be used with
170 hostnames, as in this example of finding IP addresses on the same Class C
175 The CIDR notation can only be used on IP addresses or hostnames, not in
176 variable names. So, a display filter like "ip.src/24 == ip.dst/24" is
179 IPX networks are represented by unsigned 32-bit integers. Most likely
180 you will be using hexadecimal when testing IPX network values:
182 ipx.src.net == 0xc0a82c00
184 Strings are enclosed in double quotes:
186 http.request.method == "POST"
188 Inside double quotes, you may use a backslash to embed a double quote
189 or an arbitrary byte represented in either octal or hexadecimal.
191 browser.comment == "An embedded \" double-quote"
193 Use of hexadecimal to look for "HEAD":
195 http.request.method == "\x48EAD"
197 Use of octal to look for "HEAD":
199 http.request.method == "\110EAD"
201 This means that you must escape backslashes with backslashes inside
204 smb.path contains "\\\\SERVER\\SHARE"
206 looks for \\SERVER\SHARE in "smb.path".
208 =head2 The slice operator
210 You can take a slice of a field if the field is a text string or a
212 For example, you can filter on
213 the vendor portion of an ethernet address (the first three bytes) like
216 eth.src[0:3] == 00:00:83
220 http.content_type[0:4] == "text"
222 You can use the slice operator on a protocol name, too.
223 The "frame" protocol can be useful, encompassing all the data captured
224 by B<Wireshark> or B<TShark>.
226 token[0:5] ne 0.0.0.1.1
228 frame[100-199] contains "wireshark"
230 The following syntax governs slices:
232 [i:j] i = start_offset, j = length
233 [i-j] i = start_offset, j = end_offset, inclusive.
234 [i] i = start_offset, length = 1
235 [:j] start_offset = 0, length = j
236 [i:] start_offset = i, end_offset = end_of_field
238 Offsets can be negative, in which case they indicate the
239 offset from the B<end> of the field. The last byte of the field is at offset
240 -1, the last but one byte is at offset -2, and so on.
241 Here's how to check the last four bytes of a frame:
243 frame[-4:4] == 0.1.2.3
247 frame[-4:] == 0.1.2.3
249 You can concatenate slices using the comma operator:
251 ftp[1,3-5,9:] == 01:03:04:05:09:0a:0b
253 This concatenates offset 1, offsets 3-5, and offset 9 to the end of the ftp
256 =head2 Type conversions
258 If a field is a text string or a byte array, it can be expressed in whichever
259 way is most convenient.
261 So, for instance, the following filters are equivalent:
263 http.request.method == "GET"
264 http.request.method == 47.45.54
266 A range can also be expressed in either way:
271 =head2 Bit field operations
273 It is also possible to define tests with bit field operations. Currently the
274 following bit field operation is supported:
276 bitwise_and, & Bitwise AND
278 The bitwise AND operation allows testing to see if one or more bits are set.
279 Bitwise AND operates on integer protocol fields and slices.
281 When testing for TCP SYN packets, you can write:
285 That expression will match all packets that contain a "tcp.flags" field
286 with the 0x02 bit, i.e. the SYN bit, set.
288 Similarly, filtering for all WSP GET and extended GET methods is achieved with:
292 When using slices, the bit mask must be specified as a byte string, and it must
293 have the same number of bytes as the slice itself, as in:
297 =head2 Logical expressions
299 Tests can be combined using logical expressions.
300 These too are expressable in C-like syntax or with English-like
307 Expressions can be grouped by parentheses as well. The following are
308 all valid display filter expressions:
310 tcp.port == 80 and ip.src == 192.168.2.1
312 http and frame[100-199] contains "wireshark"
313 (ipx.src.net == 0xbad && ipx.src.node == 0.0.0.0.0.1) || ip
315 Remember that whenever a protocol or field name occurs in an expression, the
316 "exists" operator is implicitly called. The "exists" operator has the highest
317 priority. This means that the first filter expression must be read as "show me
318 the packets for which tcp.port exists and equals 80, and ip.src exists and
319 equals 192.168.2.1". The second filter expression means "show me the packets
320 where not (llc exists)", or in other words "where llc does not exist" and hence
321 will match all packets that do not contain the llc protocol.
322 The third filter expression includes the constraint that offset 199 in the
323 frame exists, in other words the length of the frame is at least 200.
325 A special caveat must be given regarding fields that occur more than
326 once per packet. "ip.addr" occurs twice per IP packet, once for the
327 source address, and once for the destination address. Likewise,
328 "tr.rif.ring" fields can occur more than once per packet. The following
329 two expressions are not equivalent:
331 ip.addr ne 192.168.4.1
332 not ip.addr eq 192.168.4.1
334 The first filter says "show me packets where an ip.addr exists that
335 does not equal 192.168.4.1". That is, as long as one ip.addr in the
336 packet does not equal 192.168.4.1, the packet passes the display
337 filter. The other ip.addr could equal 192.168.4.1 and the packet would
339 The second filter says "don't show me any packets that have an
340 ip.addr field equal to 192.168.4.1". If one ip.addr is 192.168.4.1,
341 the packet does not pass. If B<neither> ip.addr field is 192.168.4.1,
342 then the packet is displayed.
344 It is easy to think of the 'ne' and 'eq' operators as having an implicit
345 "exists" modifier when dealing with multiply-recurring fields. "ip.addr
346 ne 192.168.4.1" can be thought of as "there exists an ip.addr that does
347 not equal 192.168.4.1". "not ip.addr eq 192.168.4.1" can be thought of as
348 "there does not exist an ip.addr equal to 192.168.4.1".
350 Be careful with multiply-recurring fields; they can be confusing.
352 Care must also be taken when using the display filter to remove noise
353 from the packet trace. If, for example, you want to filter out all IP
354 multicast packets to address 224.1.2.3, then using:
358 may be too restrictive. Filtering with "ip.dst" selects only those
359 B<IP> packets that satisfy the rule. Any other packets, including all
360 non-IP packets, will not be displayed. To display the non-IP
361 packets as well, you can use one of the following two expressions:
363 not ip or ip.dst ne 224.1.2.3
364 not ip.addr eq 224.1.2.3
366 The first filter uses "not ip" to include all non-IP packets and then
367 lets "ip.dst ne 224.1.2.3" filter out the unwanted IP packets. The
368 second filter has already been explained above where filtering with
369 multiply occuring fields was discussed.
371 =head1 FILTER PROTOCOL REFERENCE
373 Each entry below provides an abbreviated protocol or field name. Every
374 one of these fields can be used in a display filter. The type of the
377 =insert_dfilter_table
381 The B<wireshark-filters> manpage is part of the B<Wireshark> distribution.
382 The latest version of B<Wireshark> can be found at
383 L<http://www.wireshark.org>.
385 Regular expressions in the "matches" operator are provided with B<libpcre>,
386 the Perl-Compatible Regular Expressions library: see B<http://www.pcre.org/>.
388 This manpage does not describe the capture filter syntax, which is
389 different. See the manual page of pcap-filter(4) or, if that doesn't exist,
390 tcpdump(8), or, if that doesn't exist, L<http://wiki.wireshark.org/CaptureFilters>
391 for a description of capture filters.
395 wireshark(1), tshark(1), editcap(1), pcap-filter(4), tcpdump(8), pcap(3)
399 See the list of authors in the B<Wireshark> man page for a list of authors of