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IPSUMDUMP(1)							    IPSUMDUMP(1)

NAME
     ipsumdump - produce ASCII summary of network traffic or tcpdump(1) trace

SYNOPSIS
     ipsumdump	[-r | -i | ...] [--src, --dst, --sport, --dport, ...] [other op-
     tions] [files or interfaces]

DESCRIPTION
     The ipsumdump program reads IP packets from one or more data sources,  then
     summarizes  those	packets into a line-based ASCII file. The resulting sum-
     mary dump is easy to process with text-based tools. (But see  the	--binary
     option, which generates a smaller binary file.)

     Here   are  a  couple  lines  of  ipsumdump  output,  from  'ipsumdump  -sd
     /home/kohler/largedump.gz':

       !IPSummaryDump 1.3
       !creator "ipsumdump -sd /home/kohler/largedump.gz"
       !host max.lcdf.org
       !runtime 1000943858.353723 (Wed Sep 19 16:57:38 2001)
       !data ip_src ip_dst
       64.55.139.202 209.247.204.242
       18.26.4.9 64.55.139.202

     The '-sd' option, which is equivalent to '--src --dst', tells ipsumdump  to
     log  source and destination IP addresses.	'/home/kohler/largedump.gz' is a
     compressed tcpdump(1) file. Each data line represents  a  packet;	a  space
     separates	the two addresses. The "!data" comment describes the contents of
     each data line.

OPTIONS
   Source Options
     Source options tell ipsumdump what kind of data source to	use:  tcpdump(1)
     raw-packet  files	(--tcpdump), live network interfaces (--interface), Net-
     Flow summary files (--netflow-summary), ipsumdump	output	files  (--ipsum-
     dump), DAG or NLANR-formatted files (--dag, --nlanr), or others.

     Non-option  arguments  specify the files, or interfaces, to read. For exam-
     ple, 'ipsumdump -r eth0 eth1' will read two tcpdump(1) files, named  "eth0"
     and "eth1"; 'ipsumdump -i eth0 eth1' will read from two live network inter-
     faces, "eth0" and "eth1".

     Options that read files read from the standard input when you supply a sin-
     gle dash "-" as a filename, or when you give no filenames at all.

     --tcpdump, -r
	 Read  from  one  or more files produced by tcpdump(1)'s -w option (also
	 known as "pcap files"). Stop when all the files are exhausted. This  is
	 the  default.	Files  (except	for standard input) may be compressed by
	 gzip(1) or bzip2(1); ipsumdump will uncompress them on the fly.

     --interface, -i
	 Read from live network interfaces. When run this  way,  ipsumdump  will
	 continue  until interrupted with SIGINT or SIGHUP. When stopped, ipsum-
	 dump appends a comment to its output file, indicating how many  packets
	 were dropped by the kernel before output.

     --ipsumdump
	 Read  from  one or more ipsumdump files. Any packet characteristics not
	 specified by the input files are set to 0.

     --format=format
	 Read from one or more ipsumdump files, using the specified default for-
	 mat.  The format should be a space-separated list of content types; see
	 ToIPSummaryDump(n) for a list.

     --dag[=encap]
	 Read from one or more DAG-formatted trace  files.   For  new-style  ERF
	 dumps,  which	contain  encapsulation type information, just say --dag.
	 For old-style dumps, you must supply the right  encap	argument:  "ATM"
	 for ATM RFC-1483 encapsulation (the most common), "ETHER" for Ethernet,
	 "PPP"	for  PPP, "IP" for raw IP, "HDLC" for Cisco HDLC, "PPP_HDLC" for
	 PPP HDLC, or "SUNATM" for Sun ATM.  See <http://dag.cs.waikato.ac.nz/>.

     --nlanr
	 Read from one or more NLANR-formatted trace files (fr, fr+, or tsh for-
	 mat).	See <http://pma.nlanr.net/Traces/>.

     --netflow-summary
	 Read from one or more NetFlow summary files.  These  are  line-oriented
	 ASCII	files;	blank lines, and lines starting with '!' or '#', are ig-
	 nored. Other lines should contain 15 or more fields separated by verti-
	 cal bars '|'.	Ipsumdump pays attention to some of these fields:

	   Field  Meaning			Example
	   -----  ----------------------------	----------
	   0	  Source IP address		192.4.1.32
	   1	  Destination IP address	18.26.4.44
	   5	  Packet count in flow		5
	   6	  Byte count in flow		10932
	   7	  Flow timestamp (UNIX-style)	998006995
	   8	  Flow end timestamp		998006999
	   9	  Source port			3917
	   10	  Destination port		80
	   12	  TCP flags (OR of all pkts)	18
	   13	  IP protocol			6
	   14	  IP TOS bits			0

     --tcpdump-text
	 Read from one or more files containing tcpdump(1) textual output.  It's
	 much better to use the binary files produced by 'tcpdump  -w',  but  if
	 someone  threw those away and all you have is the ASCII output, you can
	 still make do.  Only works with tcpdump versions 3.7 and earlier.

   Data Options
     These options determine the dump's contents. Each data option adds a  field
     to  the output file; you can supply any number of data options. In the out-
     put, fields are separated by spaces. If you say '-sd',  or  the  equivalent
     '--src  --dst',  the dump's data lines will contain an IP source address, a
     space, and an IP destination address:

	 192.168.1.101 18.26.4.44

     If you supply no dump content options, ipsumdump will not create a  summary
     dump.  This  may  be useful if you're only interested in creating a tcpdump
     file with --write-tcpdump.

     Generic Options

     --timestamp, -t
	 Include packet timestamp in the dump. Example:  1000212480.005813.  For
	 NetFlow  summary  input, the packet timestamp equals the flow-end time-
	 stamp.  The timestamp has nanosecond precision  when  input  timestamps
	 had nanosecond precision.

     --first-timestamp, -T
	 Include  flow-begin  timestamp in the dump. Example: 1000212479.001937.
	 This is meaningful only for  packet  sources  that  include  flow-begin
	 timestamps, such as NetFlow summaries.

     --packet-count, -c
	 Include  packet  count in the dump.  Some kinds of logs -- such as Net-
	 Flow summary logs -- record information about flows,  not  packets.   A
	 flow  represents  multiple  packets;  the packet count says exactly how
	 many.	Example: 1.  See also --multipacket, below.

     --wire-length
	 Include wire length in the dump.  This is the packet's  length  in  the
	 capture  file, including any link headers and packet trailers.  This is
	 usually larger than --length, which returns the IP length.

     --link
	 Include the link number in the dump.  TSH-format  NLANR  logs,  NetFlow
	 summary  logs, and some IP summary logs can contain a link number.  Ex-
	 ample: 2.  For NetFlow summary logs, --link uses  the	input  interface
	 number.

     Ethernet Options

     --eth-src
	 Include   the	 Ethernet   source   address   in  the	dump.	Example:
	 "00-0A-95-A6-D9-BC".  Note that Ethernet addresses are only printed for
	 IP packets.

     --eth-dst
	 Include  the  Ethernet  destination  address  in  the	dump.	Example:
	 "00-0A-95-A6-D9-BC".  Note that Ethernet addresses are only printed for
	 IP packets.

     IP Options

     --src, -s
	 Include IP source address in the dump. Example: 192.168.1.101.

     --dst, -d
	 Include IP destination address in the dump. Example: 18.26.4.44.

     --length, -l
	 Include  IP  packet  length  in  the dump, not including any link-level
	 headers.  Example: 72.  See also --wire-length.

     --protocol, -p
	 Include IP protocol in the dump. Can be "T" for TCP, "U" for  UDP,  "I"
	 for ICMP, or a number for some other protocol.

     --fragment, -g
	 Include  IP fragment test in the dump. The field value is "F" for first
	 fragments, "f" for second and subsequent fragments, and "."  (a  single
	 period) for nonfragments.

     --fragment-offset, --fragoff, -G
	 Include IP fragment offset in the dump. The field value is the fragment
	 offset  in  bytes, possibly followed by a "+" suffix, indicating the MF
	 (more fragments) flag. Examples: "0+" (fragment offset  0,  more  frag-
	 ments	forthcoming),  552  (fragment offset 552, this is the last frag-
	 ment).

     --ip-id
	 Include IP ID field in the dump. Example: 19371.

     --ip-sum
	 Include IP checksum in the dump.  Example: 34987.

     --ip-opt
	 Include IP options in the dump. Single IP option fields have  the  fol-
	 lowing representations:

	     EOL, NOP	     Not written, but FromIPSummaryDump
			     understands 'eol' and 'nop'

	     RR 	     'rr{10.0.0.1,20.0.0.2}+5' (addresses
			     inside the braces come before the
			     pointer; '+5' means there is space for
			     5 more addresses after the pointer)

	     SSRR, LSRR      'ssrr{1.0.0.1,1.0.0.2^1.0.0.3}'
			     ('^' indicates the pointer)

	     TS 	     'ts{1,10000,!45}+2++3' (timestamps only
			     [type 0]; timestamp values 1, 10000,
			     and 45 [but 45 has the "nonstandard
			     timestamp" bit set]; the option has
			     room for 2 more timestamps; the
			     overflow counter is set to 3)

			     'ts.ip{1.0.0.1=1,1.0.0.2=2}+5'
			     (timestamps with IP addresses [type 1])

			     'ts.preip{1.0.0.1=1^1.0.0.2,1.0.0.3}'
			     (prespecified IP addresses [type 3];
			     the caret is the pointer)

	     Other options   '98' (option 98, no data),
			     '99=0:5:10' (option with data, data
			     octets separated by colons)

	 Multiple options are separated by semicolons. Any invalid option causes
	 the entire field to be replaced by a single question mark "?". A period
	 "." is used for packets with no options (except possibly EOL and NOP).

     --ip-ttl
	 Include the IP time-to-live field in the dump.

     --ip-tos
	 Include the IP type of service field in the dump.

     --ip-hl
	 Include  the  IP  header length in the dump.  The length is measured in
	 bytes.

     --capture-length
	 Include the length of captured IP data in the dump. This  can	be  less
	 than  the full IP length (see --length), since many packet capture pro-
	 grams will store only part of each packet's data.

     Transport Options

     --sport, -S
	 Include TCP or UDP source port in the dump. Example: 8928. For  non-TCP
	 or UDP packets, and for fragments after the first, this field is a sin-
	 gle dash "-".

     --dport, -D
	 Include TCP or UDP destination port in the dump. Example: 80.

     --payload-length, -L
	 Include length of packet payload in the dump. This is the length of the
	 TCP  or  UDP  payload,  for TCP or UDP packets, or the length of the IP
	 payload, for other IP packets. Example: 1000.

     --payload
	 Include the actual packet payload in the dump. This is the TCP  or  UDP
	 payload,  for TCP or UDP packets, or the IP payload, for other IP pack-
	 ets.  Output as a double-quoted C  string;  non-ASCII	characters,  and
	 double-quotes	and backslashes, appear as C backslash escapes. Example:
	 ",25\r\n\000".

     --payload-md5
	 Include an MD5 checksum of the packet payload in the dump. The  payload
	 is  as  defined  above.  In  ASCII output, the output is a 22-character
	 string consisting of characters [a-zA-Z0-9_@]; in binary output, it's a
	 16-character binary digest. Example: "sQy@IjqXnFPwZtgtwaC5Hb".

     --payload-md5-hex
	 Like --payload-md5, but in ASCII output, the checksum is printed as  32
	 hexadecimal   digits	(the  same  format  used  by  md5sum).	Example:
	 "12f6bb1941df66b8f138a446d4e8670c".

     TCP Options

     TCP header fields equal a dash "-" for non-TCP packets and non-first  frag-
     ments.

     --tcp-flags, -F
	 Include  TCP flags byte in the dump. Each flag is represented by an up-
	 percase letter. Example: "PA" (PSH and ACK are on, everything	else  is
	 off). If no flags are on, the field is "." (a single period).

	 Flag characters are "F" for FIN, "S" for SYN, "R" for RST, "P" for PSH,
	 "A"  for  ACK, "U" for URG, "E" for ECE (flag bit 6), "C" for CWR (flag
	 bit 7), and "N" for Nonce Sum (flag bit 8).

     --tcp-seq, -Q
	 Include TCP sequence number in the dump. Example: 4009339012.

     --tcp-ack, -K
	 Include TCP acknowledgement number in the dump. Example: 4009339012.

     --tcp-window, -W
	 Include TCP receive window in the dump.  This value is  not  scaled  by
	 the connection's window scale, if any.  Example: 480.

     --tcp-opt, -O
	 Include TCP options in the dump. Single TCP option fields have the fol-
	 lowing representations:

	     EOL, NOP	     No representation
	     MSS	     'mss1400'
	     Window scale    'wscale10'
	     SACK permitted  'sackok'
	     SACK	     'sack95-98'; each SACK block
			     is listed separately
	     Timestamp	     'ts669063908:38382731'
	     Other options   '98' (option 98, no data),
			     '99=0:5:10' (option with data, data
			     octets separated by colons)

	 Multiple options are separated by semicolons. Any invalid option causes
	 the entire field to be replaced by a single question mark "?". A period
	 "." is used for packets with no options (except possibly EOL and NOP).

     --tcp-sack
	 Include  SACK-related	TCP  options in the dump, using the format given
	 under "--tcp-opt", above.

     UDP Options

     UDP header fields equal a dash "-" for non-UDP packets and non-first  frag-
     ments.

     --udp-length
	 Include  UDP length in the dump. This is the length reported in the UDP
	 packet header. Example: 1000.

     ICMP Options

     ICMP header fields equal a dash "-"  for  non-ICMP  packets  and  non-first
     fragments.

     --icmp-type
	 Include  ICMP	type  in the dump. Example: 3. A dash is output for non-
	 ICMP packets.

     --icmp-code
	 Include ICMP code in the dump. Example: 8.

     --icmp-type-name
	 Include ICMP type in the dump, using textual names if known.  Examples:
	 "echo", "echo-reply", 100.

     --icmp-code-name
	 Include  ICMP code in the dump, using textual names if known. Examples:
	 "filterprohibited", "srcroutefail", "reassembly", 97.

   Other Options
     --output=file, -o file
	 Write the summary dump to file instead of to the standard output.

     --binary, -b
	 Write the summary dump in binary format. See below  for  more	informa-
	 tion.

     --write-tcpdump=file, -w file
	 Write processed packets to a tcpdump(1) file -- or to the standard out-
	 put,  if  file is a single dash "-" -- in addition to the usual summary
	 output.  Options including --filter and dump contents	require  IP;  in
	 the  presence of these options, the output tcpdump(1) file will contain
	 only IP packets.  (ARP packets, for example, will not be written.)

     --no-tcpdump-nano
	 The file written for  --write-tcpdump	will  use  microsecond-precision
	 timestamps, rather than nonsecond-precision timestamps (the default).

     --no-payload
	 Do not include IP packet payloads in any --write-tcpdump output.

     --filter=filter, -f filter
	 Only  include packets and flows matching a tcpdump(1) filter. For exam-
	 ple, 'ipsumdump -f "tcp && src net 18/8"' will summarize data only  for
	 TCP  packets  from net 18. (The syntax for filter is currently a subset
	 of tcpdump's syntax.)

     --bad-packets
	 Print lines like "!bad IP header length 4" for packets with no IP head-
	 ers, bad IP headers, or bad TCP/UDP headers. (A bad header has  an  in-
	 correct  length  or  unexpected  version,  or is spread across multiple
	 fragments.)  The "!bad" line will immediately precede the normal output
	 line.	Whether or not --bad-packets is true, a dash "-" is printed  for
	 any piece of information that came from a bad header, or that came from
	 a portion of the header that was not captured.

     --anonymize, -A
	 Anonymize  IP addresses in the output. The anonymization preserves pre-
	 fix and class. This means, first, that two  anonymized  addresses  will
	 share	the same prefix when their non-anonymized counterparts share the
	 same prefix; and second, that anonymized addresses will be in the  same
	 class	(A,  B,  C,  or  D)  as  their	non-anonymized counterparts. The
	 anonymization algorithm comes from tcpdpriv(1); it works like 'tcpdpriv
	 -A50 -C4'.

	 If --anonymize and --write-tcpdump are both on, the tcpdump output file
	 will have anonymized IP addresses. However, the file will  contain  ac-
	 tual packet data, unlike tcpdpriv output.

     --no-promiscuous
	 Do  not place interfaces into promiscuous mode. Promiscuous mode is the
	 default.

     --sample=p
	 Sample packets with probability p. That is, p	is  the  chance  that  a
	 packet  will  cause  output to be generated. The actual probability may
	 differ from the specified probability, due to fixed  point  arithmetic;
	 check	the output for a "!sampling_prob" comment to see the real proba-
	 bility.  Strictly speaking, this option samples records,  not	packets;
	 so for NetFlow summaries without --multipacket, it will sample flows.

     --multipacket
	 Supply  this option if you are reading NetFlow or IP summaries -- files
	 where each record might represent multiple packets  --  and  you  would
	 like the output summary to have one line per packet, instead of the de-
	 fault one line per record. See also --packet-count, above.

     --collate
	 Sort output packets by increasing timestamp. Use this option when read-
	 ing from multiple tcpdump(1) files to ensure that the output has sorted
	 timestamps.  Combine --collate with --write-tcpdump to collate overlap-
	 ping tcpdump(1) files into a single, sorted tcpdump(1) file.

     --interval=time
	 Process packets for time, an interval length in seconds (or give a suf-
	 fix like '2m' or '1hr'). For --interface, ipsumdump will quit after  it
	 has run for time. For other options, ipsumdump will quit before writing
	 a packet whose timestamp is more than time seconds later than the time-
	 stamp on the first packet it sees.

     --skip-packets=count
	 Skip the first count packets.

     --limit-packets=count
	 Output at most count packets, then quit.

     --map-address=addrs
	 addrs	is  a space- or comma-separated list of IP addresses and/or pre-
	 fixes. When the summary dump completes, ipsumdump will write those  ad-
	 dresses  to  the  standard error, paired with their anonymized counter-
	 parts.

     --record-counts=time
	 Useful when reading from interfaces. This option  causes  ipsumdump  to
	 write	a comment recording the cumulative number of packets output, and
	 the number of packets dropped by  the	kernel	before	ipsumdump  could
	 process  them,  every	time seconds. (Or you can say, for example, '2m'
	 for 2 minutes.) A sample comment:

	   !counts out 0 kdrop 0

	 This says that ipsumdump has output 0 records, and the kernel	reported
	 0 packet drops since ipsumdump began.

     --random-seed=seed
	 Set  the random seed deterministically to seed, an unsigned integer. By
	 default, the random  seed  is	initialized  to  a  random  value  using
	 /dev/random,  if  it  exists, combined with other data. The random seed
	 indirectly determines which packets are  sampled,  and  the  values  of
	 anonymized IP addresses.

     --no-mmap
	 Do  not use memory mapping when reading files. This may prevent crashes
	 if you feed ipsumdump a corrupted file. See BUGS, below.

     --quiet, -q
	 Do not print a progress bar to standard error. This is the default when
	 ipsumdump isn't running interactively.

     --no-headers
	 Do not print the IP summary dump header lines that make the dump  self-
	 describing.

     --config
	 Do  not  produce a summary. Instead, write the Click configuration that
	 ipsumdump would run to the standard output.

     --verbose, -V
	 Produce more verbose error messages.

     --help, -h
	 Print a help message to the standard output, then exit.

     --version, -v
	 Print version number and license information to  the  standard  output,
	 then exit.

SIGNALS
     When killed with SIGTERM or SIGINT, ipsumdump will exit cleanly by flushing
     its  buffers.  If you want it to flush its buffers without exiting, kill it
     with SIGHUP.

EXAMPLES
     The '-tsSdDp' option set covers the most commonly useful information  about
     each  packet:  timestamp, source address, source port, destination address,
     destination port, and protocol. Invoking 'ipsumdump -i eth1 -tsSdDp'  might
     produce output like this:

       !IPSummaryDump 1.3
       !creator "ipsumdump -i eth1 -tsSdDp"
       !host max.lcdf.org
       !runtime 1000967293.569808 (Wed Sep 19 23:28:13 2001)
       !data timestamp ip_src sport ip_dst dport ip_proto
       1000967303.641581 64.71.165.130 80 192.168.1.101 4450 T
       1000967303.670506 64.71.165.130 80 192.168.1.101 4450 T
       1000967303.882621 18.26.4.44 - 192.168.1.101 - I
       1000967304.253874 64.71.165.130 80 192.168.1.101 4442 T
       1000967304.390016 192.150.187.11 53 192.168.1.101 1299 U
       1000967304.425992 207.171.182.16 80 192.168.1.101 4451 T

     Here is the same data, anonymized with -A:

       !IPSummaryDump 1.3
       !creator "ipsumdump --ipsumdump -A -tsSdDp"
       !host max.lcdf.org
       !runtime 1000968019.67508 (Wed Sep 19 23:40:19 2001)
       !data timestamp ip_src sport ip_dst dport ip_proto
       1000967303.641581 29.50.142.215 80 204.196.101.50 4450 T
       1000967303.670506 29.50.142.215 80 204.196.101.50 4450 T
       1000967303.882621 89.142.236.79 - 204.196.101.50 - I
       1000967304.253874 29.50.142.215 80 204.196.101.50 4442 T
       1000967304.390016 204.224.59.219 53 204.196.101.50 1299 U
       1000967304.425992 192.230.64.231 80 204.196.101.50 4451 T

BINARY FORMAT
     Binary  ipsumdump	files  begin with several ASCII lines, just like regular
     ipsumdump files. The line "!binary" indicates that the rest  of  the  file,
     starting  immediately  after  the newline, consists of binary records. Each
     record looks like this:

	+---------------+------------...
	|X|record length|    data
	+---------------+------------...
	 <---4 bytes--->

     The initial word of data contains the record length in bytes. (All  numbers
     in  the  file are stored in network byte order.) The record length includes
     the initial word itself, so the minimum valid record length is 4. The high-
     order bit "X" is the metadata indicator. It is zero for regular packets and
     one for metadata lines.

     Regular packet records have binary fields stored in the order indicated  by
     the "!data" line, as follows:

	Field Name     Length  Description
	timestamp	  8    timestamp sec, usec
	ntimestamp	  8    timestamp sec, nsec
	first_timestamp   8    timestamp sec, usec
	first_ntimestamp  8    timestamp sec, nsec
	ip_src		  4    source IP address
	ip_dst		  4    destination IP address
	sport		  2    source port
	dport		  2    destination port
	ip_len		  4    IP length field
	ip_proto	  1    IP protocol
	ip_id		  2    IP ID
	ip_frag 	  1    fragment descriptor
			       ('F', 'f', or '.')
	ip_fragoff	  2    IP fragment offset field
	tcp_seq 	  4    TCP seqnece number
	tcp_ack 	  4    TCP ack number
	tcp_flags	  1    TCP flags
	tcp_opt 	  ?    TCP options
	tcp_sack	  ?    TCP SACK options
	payload_len	  4    payload length
	count		  4    packet count

     Each  field is Length bytes long. Variable-length fields have Length "?" in
     the table; in a packet record, these fields  consist  of  a  single  length
     byte, followed by that many bytes of data.

     The  data	stored in a metadata record is just an ASCII string, ending with
     newline, same as in a regular ASCII IPSummaryDump file. "!bad" records, for
     example, are stored this way.

CLICK
     The ipsumdump program uses the Click modular router, an  extensible  system
     for processing packets. Click routers consist of C++ components called ele-
     ments.  While some elements run only in a Linux kernel, most can run either
     in the kernel or in user space, and there are user-level elements for read-
     ing packets from libpcap or from tcpdump files.

     Ipsumdump creates and runs a user-level Click configuration.  However,  you
     don't  need  to install Click to run ipsumdump; the libclick directory con-
     tains all the relevant parts of Click, bundled into a library.

     If you're curious, try running 'ipsumdump --config' with some other options
     to see the Click configuration ipsumdump would run.

     This is, I think, a pleasant way to write a packet processor!

COMPATIBILITY
     Version 1.0 of the IPSummaryDump ASCII file format  expressed  'ip_fragoff'
     fields in units of 8 bytes.  In version 1.1 and later, these fields are ex-
     pressed in bytes.

     Version  1.1  used "W" for CWR in tcp_flags fields.  Early releases in Ver-
     sion 1.0 versions printed a number between 0 and 255 for tcp_flags, or used
     "X" and "Y" for ECE and CWR.  Version 1.2 and later uses "C" for CWR.

     The names of "!data" fields were formerly printed in quotes, and could con-
     tain spaces, like the following:

       !data 'timestamp' 'ip src' 'sport' 'ip dst' 'dport' 'ip proto'

     ipsumdump still understands files with the old format.

     Version 1.2 could unfortunately contain incorrect MD5 checksums for packets
     with both link-level headers and short payloads, such as pure TCP	acknowl-
     edgments.

BUGS
     Ipsumdump	can use the mmap(2) system call to access files, which often has
     better performance.  Unfortunately,  if  ipsumdump  memory-maps  a  corrupt
     file, it may crash with a segmentation violation.

SEE ALSO
     tcpdump(1), tcpdpriv(1), click(1), ipaggcreate(1)

     See http://www.read.cs.ucla.edu/click/ for more on Click.

AUTHOR
     Eddie Kohler <kohler@cs.ucla.edu>, based on the Click modular router.

     Extensive	feedback  and  suggestions  from  Vern	Paxson	<vern@icir.org>.
     Anonymization algorithm from tcpdpriv(1) by Greg Minshall.

Version 1.86			   2015-02-22			    IPSUMDUMP(1)

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