Provided by: nfdump_1.7.1-2_amd64 
NAME
nfdump — flow display and analysis program
SYNOPSIS
nfdump -r flowpath [-w outfile] [-f filterfile] [-C config] [-R filelist] [-M dirlist]
[-O order] [-t timewin] [-c num] [-a] [-A aggregation] [-b] [-B] [-I] [-D nameserver]
[-G geoDB] [-s statistic] [-n num] [-o format] [-6] [-q] [-N] [-i ident]
[-v flowfile] [-E flowfile] [-x flowfile] [-z] [-y] [-j] [-J num] [-X] [-Z] [-T] [-V]
[-h] [filter]
DESCRIPTION
nfdump reads the flow data from one or more binary files, created by any nfdump collector
nfcapd, nfpcapd and sfcapd. It processes and lists the flows in many different output
formats and can create a wide range of statistics.
nfdump has a very powerful flow filter to process flows. The filter syntax is very similar
to tcpdump, but adapted and extended for flow filtering. A flow filter may also contain
arrays of many thousand IP addresses etc. to search for specific records.
nfdump can aggreagte flows according to a user defined number of elements. This masks
certain elements and allows to sum up flow records matching the same values.
The combination of flow filtering and aggregation as input for any flow statistics allows
complex flow processing. Pre-filtered and aggregated flow data may also be written back into
a binary flow file, which again may be processed with nfdump
nfdump can enrich the listing of flows with geo location information and AS information,
unless AS information is already available in the flow records. IP addresses can be tagged
with a two letter country code, or with a longer location label containing the geographic
region, country and city. The geo location and AS information is retrieved from the
optional geoDB database, created by the geolookup program from the nfdump tools. geolookup
uses the Maxmind database GeoDB or GeoLite2 to create a binary lookup database for nfdump
Please check the geolooup(1) man page for more details.
The options are as follows:
-r flowpath
Reads flow records from this path. flowpath may be a single file, or a directory
containing any number of flow files or sub directories. All files are processed in
the order, as listed by the OS.
-w outfile
Writes all processed records into outfile instead of printing. The flowfile is a
binary flow file and may be processed again with nfdump This can be useful to limit
flows according to a flow filter and/or specific flow aggregation.
-f filterfile
Reads the flow filter from filterfile. This can be useful for very long or
structured filters, with comments and long lists. Note: Any filter specified
directly on the command line takes precedence over the filterfile.
-C config
Read more options from file config. nfdump tries to read by default
%prefix/etc/nfdump.config. This may be overwritten by the environment valiable
NFCONF which again may be overwritten by this option -C. In order to prevent reading
any config file, even if it would exist set -C none. A config file is not required,
but may be handy for often used output formats etc.
-O order
Sets an output order for records to be printed as text output. This order applies
after all records processing, such as filtering, and aggregation and before
printing.
flows Sort according to the number of flows
packets Sort according to (in)packets
ipkg Same as packets
opkg Sort according to output packets
bytes Sort according to (in)bytes
ibyte Same as bytes
obyte Sort according to output bytes
pps Sort according to (in)packets per second
ipps Same as ipps
opps Sort according to out packets per second
bps Sort according to (in)bytes per second
ibps Same as bps
obps Sort according to output bytes per second
bpp Sort according to (in)bytes per packet
ibpp Same as bpp
obpp Sort according to output packets
tstart Sort according to start time of flow - former -m
tend Sort according to end time of flows
duration Sort according to duration of flows
-t timewin
Set time window to process flows. This option is considered legacy andmay be
replaced with a filter primitiv in future rleases. The time window is specified as:
YYYY/MM/dd.hh:mm:ss[-YYYY/MM/dd.hh:mm:ss]. Any parts of the time spec may be
omitted e.g YYYY/MM/dd expands to YYYY/MM/dd.00:00:00-infinity and processes all
flow from a given day onwards. The time window may also be specified as +/- n. In
this case it is relativ to the beginning or end of all flows. +10 means the first 10
seconds of all flows, -10 means the last 10 seconds of all flows.
-c num Limit the number of records to be processed to the first num records, which passwd
the filter.
-a Aggregate flow records. The default aggregation is done at connection level by
taking the 5-tuple protocol, srcip, dstip, srcport and dstport. This way of
aggregation may be overwritten by option -A
-A aggregation
Sets the list of elements in a flow record to be aggregated. aggregation is a ','
separated list of any number of v9/ipfix elements. The following elements are
accepted:
proto IP protocol
srcip Source IP address
dstip Destination IP address
srcip4/net IPv4 source IP address with applied netmask
srcip6/net IPv6 source IP address with applied netmask
dstip4/net IPv4 destination IP address with applied netmask
dstip6/net IPv6 destination IP address with applied netmask
srcnet Apply netmask srcmask in netflow record for source IP
dstnet Apply netmask dstmask in netflow record for dest IP
srcport Source port
dstport Destination port
srcmask Source mask
dstmask Destination mask
srcvlan Source vlan label
dstvlan Destination vlan label
srcas Source AS number
dstas Destination AS number
nextas BGP Next AS
prevas BGP Previous AS
inif SNMP input interface number
outif SNMP output interface number
next IP next hop
bgpnext BGP next hop
insrcmac In source MAC address
outdstmac out destination MAC address
indstmac In destintation MAC address
outsrcmac Out source MAC address
tos Source type of service
srctos Source type of Service
dsttos Destination type of Service
mpls1 MPLS label 1
mpls2 MPLS label 2
mpls3 MPLS label 3
mpls4 MPLS label 4
mpls5 MPLS label 5
mpls6 MPLS label 6
mpls7 MPLS label 7
mpls8 MPLS label 8
mpls9 MPLS label 9
mpls10 MPLS label 10
router IP address of exporting router
odid observation domain ID
opid observation point ID
xsrcip X-late source IP address, if compiled with NSEL support
xdstip X-late destination IP address, if compiled with NSEL support
xsrcport X-late source port, if compiled with NSEL support
xdstport X-late destination port, if compiled with NSEL support
nfdump automatically compiles the appropriate output format for the selected
aggregation elements unless an explicit output format -o is given. The automatic
output format is identical to
-o 'fmt:%ts %td <fields> %pkt %byt %bps %bpp %fl'
where <fields> represents the selected aggregation tags.
-b Aggregate flow records as bidirectional flows. This automatically implies -a.
Aggregation is done on connection level by taking the 5-tuple protocol, srcip,
dstip, srcport and dstport The reverse order applies for the corresponding reverse
flow. Input and output packets/bytes are counted and reported separately. Both flows
are merged into a single record with corresponding input and output counters. An
appropriate output format is selected automatically, which may be overwritten by any
-o format option.
-B Similar to option -b but tries to guess the correct client to server direction.
Automagically swaps flows if src port is < dst port for TCP and UDP flows and src
port < 1024 and dst port > 1024. Some exporters do not really care sending the
flows in proper order. It's considered to be a conveniency option.
-I Print flow statistics of a single file or the summary of all the files specified by
-r flowpath.
-g Print for each flow file given by -r flowpath a one line summary, which can be
easily used by gnu plot.
-D nameserver
Sets the nameserver to translate hostnames into IP addresses in filter expressions.
See filter below for more details.
-G geoDB
Use geoDB as geo lookup DB for geo location and AS lookups. nfdump tries to read
the environment variable NFGEODB for the path of geoDB. The option -G overwrites
NFGEODB. In order to prevent reading any geoDB file, even if it would exist set -G
none.
-s statistic [:p [/orderby]]
Generate the Top N flow record or flow element statistic. By optionally adding :p to
statistic, the statistic is additionally split up into the transport layer
protocols. By default the statistic is transport protocol independent. Each
statistic may be ordered by the optional parameter orderby This can be flows,
packets, bytes, pps, bps or bpp. You may specify more than one orderby option, which
results in the same statistic but ordered differently. If no orderby is given, the
statistic is ordered by flows. You can specify as many -s flow element statistics as
needed on the command line for the same run.
statistic can be:
record aggregated netflow records.
srcip source IP addresses
dstip destination IP addresses
ip any (src or dst) IP addresses
nhip next hop IP addresses
nhbip BGP next hop IP addresses
router exporting router IP address
srcport source ports
dstport destination ports
port any (source or destination) ports
tos type of service - default src
srctos src type of service
dsttos dst type of service
dir flow directions ingress/egress
srcas source AS numbers
dstas destination AS numbers
srcgeo 2 letter geo source country code
dstgeo 2 letter geo destination country code
as any (source or destination) AS numbers
inif input interface
outif output interface
if any interface
inam input interface name
onam output interface name
srcmask src mask
dstmask dst mask
srcvlan src vlan label
dstvlan dst vlan label
vlan any vlan label
insrcmac input src MAC address
outdstmac output dst MAC address
indstmac input dst MAC address
outsrcmac output src MAC address
srcmac any src MAC address
dstmac any dst MAC address
inmac any input MAC address
outmac any output MAC address
mask any mask
proto IP protocols
mpls1 MPLS label 1
mpls2 MPLS label 2
mpls3 MPLS label 3
mpls4 MPLS label 4
mpls5 MPLS label 5
mpls6 MPLS label 6
mpls7 MPLS label 7
mpls8 MPLS label 8
mpls9 MPLS label 9
mpls10 MPLS label 10
sysid Internal SysID of exporter
nbar nbar ID
ja3 ja3 hashes
odid observation domain ID
opid observation point ID
vrf/ivrf ingress vrf
evrf egress vrf
ivrfnam ingress vrf name
evrfnam egress vrf name
NSEL/ASA statistics
event NSEL/ASA event
xevent NSEL/ASA extended event
xsrcip NSEL/ASA translated src IP address
xsrcport NSEL/ASA translated src port
xdstip NSEL/ASA translated dst IP address
xdstport NSEL/ASA translated dst port
iacl NSEL/ASA ingress ACL
iace NSEL/ASA ingress ACE
ixace NSEL/ASA ingress xACE
eacl NSEL/ASA egress ACL
eace NSEL/ASA egress ACE
exace NSEL/ASA egress xACE
NAT statistics
nevent NAT event
nsrcip NAT src IP address
nsrcport NAT src port
ndstip NAT dst IP address
ndstport NAT dst port
% nfdump -s srcip -s ip/flows/bytes -s record/bytes
-n num Set the number of records to be printed to num. This option applies to -s statistics
as well as to ordered output -O -or -aggreated -records -a The default is set to 10
for statistics and unlimited for the other use cases. To disable the limit, set num
to 0.
-o format
Sets the output format to print flow records. has many different output formats
already predefined. format may be one of the options below:
raw Print the full flow record on multiple lines. This prints all available
information.
fmt: user Print the flow records according the format user. This is a very flexible
and powerful way to format flow records. See the section OUTPUT below for
more details on how to compile your own format.
json Print full record as a separate json object.
csv Legacy .csv format - will get removed in future releases. Please use json
instead.
pipe Legacy '|' separated format - will get removed in future releases. Please
use json instead.
Already predefined fmt formats:
line Print each flow on one line. Default format.
long Print each flow on one line with more details
biline Same as line, but for bi-directional flows
bilong Same as long, but for bi-directional flows
gline Same as line, but add country code to IPs. If a geoDB file is supplied
this is the default output format
glong Same as long, but add country code to IPs
extended Print each flow on one line with even more details.
nsel Print format for NSEL event records. Default format if NSEL/NAT support
has been compiled in.
nel Print format for NAT event records.
The nfdump config file may contain additional formats. If you want to add new
formats or change existing ones, check the config file.
IPv6 addresses are printed condensed in any fmt defined format to prevent cluttering
the output with large blank blocks. A condensed IPV6 uses max 16 characters. If it
is longer, then the middle part of the IP is cut out and replaced be "..". For
previewing an output, this fits most needs. For a listing with the full IPV6
addresses add option -6.
-6 Print full length of IPv6 addresses in output instead of condensed.
-q Quiet mode. Suppress the header line and the statistics at the bottom of text
outputs.
-N Print plain numbers in output without scaling. Easier for output parsing with 3rd
party tools.
-i ident
Change the ident label in the file, specified by -r to ident
-v flowfile
Verify the consistency of flowfile and print the file parameters and number of
records.
-E flowfile
Print the exporter and sampler list if found in flowfile. Additional statistics per
exporter are printed with number of flows, packets and sequence errors.
-x flowfile
This options works on nfdump version 1.6.x files only and may get removed in future.
Scans and prints extension maps located in flowfile
-z Compress flow files with LZO1X-1 compression. Fastest compression.
-y Compress flow files with LZ4 compression. Fast and efficient.
-j Compress flow files with bz2 compression. Slow but most efficient. May be used for
archiving files or if you are really short of spce.
-J num Change compression for any number of files given by option -r flowpath num: 0
uncompress, 1: LZO1X-1, 2: bz2, 3: LZ4 compression. This option may be used for
archiving flow files and changing the compression to use less disk space.
-X Compiles the filter syntax and dumps the filter engine table to stdout. This is for
debugging purpose only.
-Z Check filter syntax and exit. Sets the return value accordingly.
-R filelist
Select a range of files. This option is mainly used by old NfSen and documented here
as legacy opton.
/any/dir Read recursively all files in directory dir.
/dir/file Read all files beginning with file.
/dir/file1:file2 Read all files from file1 to file2.
When using in combination with a sub hierarchy: /dir/sub1/sub2/file1:sub3/sub4/file2
Read all files from sub1/sub2/file1 sub3/sub4/file2 iterating over all required
hierarchy levels. Note: files are read in alphabetical order.
-M dirlist
Read the same file hierarchy from multiple directories. This option is mainly used
by old NfSen and documented here as legacy option. Example:
/any/path/to/dir1:dir2:dir3 etc. and will be expanded to the directories:
/any/path/to/dir1, /any/path/to/dir2 and /any/path/to/dir3. Any number of colon
separated directories may be given. The files to read are specified by -r or -R and
are expected to exist in all the given directories. The options -r and -R must not
contain any directories when used in combination with -M.
-T Tag IP addresses with a prepending cntrl-A character, to allow output parsers to
hook in. This option is mainly used by old NfSen and documented here as legacy
option.
-V Print nfdump version and exit.
-h Print help text on stdout with all options and exit.
filter selects, which records will be further processed. If no filter is given, all records
will be processed. Otherwise, only those flows matching the filter will be processed. Any IP
address in a filter may be specified as IPv4 or IPv6.
The filter syntax is similar to tcpdump but adapted and extended for flow records. The
filter can be either specified on the command line after all options or in a separate file.
It can span several lines. Anything after a '#' is treated as a comment and ignored to the
end of the line. There is virtually no limit in the length of the filter expression. All
keywords are case insensitive.
A single filter primitiv filters a single element of a flow record. A filter consists of
one or more primitives, which are linked together:
expr and expr
expr or expr
not expr and (expr)
Possible filter primitives:
@include file Expands the content of file into the current filter
count comp number True if the comparison with the record counter matches number Each
record gets assigned a record number at the time it is read from file.
Therefore this record number is not unique and may change, depending on
the order files are read.
ident string True if the record ident field matches string. This filter can be used
to filter out different sources.
inet
ipv4 True if source and destination IP of a record are IPv4 IPs.
inet6
ipv6 True if source and destination IP of a record are IPv6 IPs.
proto protocol True if the record protocol field matches protocol. protocol can be a
symbolic name such as tcp, udp, icmp, ah, esp, ipip, and many more or a
protocol number, such as 6, 17 for protocol tcp and udp.
tun proto protocol True if the record tunnel protocol field matches protocol. protocol may
be a symbolic name or protocol number.
ip ipaddr
src ip ipaddr
dst ip ipaddr True if the respective IP field of the record matches ipaddr. ipaddr may
be an IPv4 or IPv6 address or a symbolic hostname. In this case a DNS
lookup resolves the hostname to one or more IP addresses. If more than
one IP results, all IPs are chained together in an or chain. (IP or IP
or IP). If ip is not specified with src or dst the source or
destination IP may match.
host ipaddr host is just a synonym for ip (See above)
ip in [iplist]
src in ip [iplist]
dst ip [iplist] True if the respective IP field of the record is in iplist. iplist is a
space or ',' separated list of IP addresses or networks in CIDR
notation. This is the prefered way to search in large list of IP
addresses and networks and is much more efficient than to chain all IP
addresses together. (IP1 or IP2 or IP3). The iplist may contain several
hundreds to thousand IPs and/or networks. For just a few IPs use an or
chain, otherwise use an iplist If ip is not specified with src or dst
the source or destination IP may match.
net network netmask
src net network netmask
dst net network netmask
net network/netbits
src net network/netbits
dst net network/netbits
True if the respective IP field of the record matches the network if the
corresponding netmask or netbits are applied to the IP address. If net
is not specified with src or dst the source or destination IP may match.
geo geoloc
src geo geocode
dst geo geocode True, if the 2-letter country code resolved by geolookup of the source
or destination IP address matches geocode. This filter works only, if a
valid geoDB is specified. See geo location option above. The 2-letter
country code corresponds to the maxmin DB definitions. if geo is not
specified with src or dst the source or destination geo location code
may match.
tunip ipaddr
src tunip ipaddr
dst tunip ipaddr True if the respective tunnel IP field of the record matches ipaddr. If
tunip is not specified with src or dst the source or destination tunnel
IP may match.
port comp num
src port comp num
dst port comp num True if the comparison of the respective port field matches num See comp
for the comparator details. If port is not specified with src or dst the
source or destination port may match.
port in [portlist]
src port in [portlist]
dst port in [portlist]
True if the respective port field of the record is in portlist. portlist
is a space or ',' separated list of port numbers. This is the prefered
way to search in large list of port numbers and is much more efficient
than to chain all ports together. (PORT1 or PORT2 or PORT3). portlist
may contain several hundreds to thousand of port numbers. If port is
not specified with src or dst the source or destination port may match.
icmp-type num
icmp-code num True if the respective icmp field of the record matches num. This
automatically implies proto icmp.
engine-type num
engine-id num
sysid num True if the respective fields of the record matches num engine type and
ID are set by the exporting device, sysid refers to the nfdump collector
internal assigned number. See also option -E above.
if num
in if num
out if num True if the respective interface fields of the record matches num. This
ID may correspond to the SNMP ID of the interface but depends on the
exporter. If if is not specified with in or out the input or output
interface may match.
as comp num
src as comp num
dst as comp num
prev as comp num
next as comp num True if the comparison of the respective AS fields matches nfdump
supports 32-bit AS numbers every where. Without or the source or
destination AS may match. See comp for the comparator details.
as in [aslist]
src as in [aslist]
dst as in [aslist]
prev as in [aslist]
next as in [aslist]
True if the respective AS field of the record is in aslist. aslist is a
space or ',' separated list of AS numbers. This is the prefered way to
search in large list of AS numbers and is much more efficient than to
chain all ports together. aslist may contain several hundreds to
thousand of AS numbers. If as is not specified with src, dst, prev or
next the source or destination AS may match.
mask bits
src mask bits
dst mask bits True if the respective mask bit field of the record matches bits If mask
is not specified with src or dst the source or destination mask bits may
match.
vlan num
src vlan num
dst vlan num True if the respective vlan field of the record matches num If vlan is
not specified with src or dst the source or destination vlan may match.
flags tcpflags True if the respective tcp flags field of the record matches any of the
given tcpflags. tcpflags is a string combination of all flags to be
tested:
A ACK.
S SYN.
F FIN.
R Reset.
P Push.
U Urgent.
X All flags on.
The order of the flags within tcpflags is not relevant. Flags not
mentioned are treated as don't care. In order to get those flows with
only the SYN flag set, use the syntax
flags S and not flags AFRPU
router ip ipaddr True if the ip address of the sending router matches ipaddr as valid
IPv4/IPv6 address.
next ip ipaddr True if the field next-ip of the record matches ipaddr as valid
IPv4/IPv6 address.
bgpnext ip ipaddr True if the field bgpnext-ip of the record matches ipaddr as valid
IPv4/IPv6 address.
mac macaddr
in mac macaddr
in src mac macaddr
in dst mac macaddr
out mac macaddr
out src mac macaddr
out dst mac macaddr
True if the respective mac address field of the record matches macaddr
By prepending mac with any combination of a direction specifier as
defined by CISCO v9 the test is limited to those mac addresses only.
Otherwise multiple matches are possible. Without any specifiers any mac
address is tested against macaddr
mpls labelN comp number
True if the comparison of the mpls label N with N as mpls label number
1..10 matches number Filters according a specific number in the mpls
label stack.
mpls eos comp number
True if the comparison of the end of stack mpls label matches number
mpls expN comp number
True if the comparison of the experimental bits 0..7 of mpls label N
with N as mpls label number 1..10 matches number
packets comp num
in packets comp num
out packets comp num
True if the comparison of the packet counter in the flow record matches
num. num may contain any valid scaling factor such as k, m, g Example:
packets > 1k. For a single flow packets and in packets is equivalent and
describes the number of packets from source to destination. In case of
a bi-directional flow (sent by an exporter or combined by option --B )
the packet counter for the reverse flow can be tested with out packet
bytes comp num
in bytes comp num
out bytes comp num True if the comparison of the byte counter in the flow record matches
num. num may contain any valid scaling factor such as k, m, g Example:
bytes > 1k bytes and in bytes is equivalent and describes the number of
bytes from source to destination. In case of a bi-directional flow
(sent by an exporter or combined by option --B ) the byte counter for
the reverse flow can be tested with out bytes
flow comp num True if the comparison of the flow counter in the flow record matches
num. num may contain any valid scaling factor such as k, m, g For each
received flow, the flow counter is set to 1, unless the exporter sends
this information. If multiple flows are aggregated, this counter is
increased respectively.
tos num True if the type of service field of the flow record matches num
flowdir direction True, if the flow direction field in the flow record matches direction.
direction may be ingress, egress, 0 for ingress, or 1 for egress
duration comp time True if the calculated duration of a flow (tend - tstart) compares to
time. The duration is specified in msec (milliseconds)
pps comp num True if the calculated value of in-packets/duration (packets per second)
compares with the number num. num may contain any valid scaling factor
such as k, m, g
bps comp num True if the calculated value of 8*in-bytes/duration (bits per second)
compares with the number num. num may contain any valid scaling factor
such as k, m, g
bpp comp num True if the calculated value of in-bytes/in-packets (bytes per packet)
compares with the number num. num may contain any valid scaling factor
such as k, m, g
observation domain id comp number
observation point id comp number
True if the comparison of the observation domain ID or point ID field
respectively matches number
payload filters Some exporters, such as yaf or the nfdump collector nfpcap can send
payload data along the netflow information. If such payloads are sent it
can be filtered according the filter primitives below:
payload content 'string'
True if the string string is found in the payload data. string must be
quoted with single or double quotes: 'string', “string”
payload regex 'regex'
payload regex 'regex' flags
True if regex matches the payload data. regex searches over the full
payload length. A ' ' byte does not stop the match process. regex must
be quoted with single or double quotes: 'regex' or “regex” The regex
engine understands the following reduced syntax:
(...) subexpressions/capture ranges
| the "or" operator
^and $ anchors
[...] and [^...] character classes
?, *, +, simple quantifiers
*?, +?, ?? lazy quantifiers
{<num>}, {<num1>,<num2>} complex quantifiers
flags are otional can be:
m multiline
i case insensitive matching
s
payload ja3 md5string
True, if the payload contains the start of an SSL/TLS handshake and the
calculated jas value of the handshake matches md5string
payload ja3 defined
True, if the payload contains the start of an SSL/TLS handshake and a
valid ja3 value can be calculated. Useful to mask out all flow records
with no SSL/TLS traffic in order to generate a -s ja3 statistic.
nprobe implemented elements
client latency comp time
server latency comp time
True, if the respective latency field in the flow record compares to
time. time is specified in msec.
CISCO ASA, network security event logging (NSEL) and NAT event logging (NEL) specific
filters:
NSEL specific filters:
asa event event True if the NSEL event type of an event record matches event which may
be: ignore, create, term, delete, deny
asa event comp number
True if the comparison of the NSEL event type of an event records
matches number as a number.
asa event denied reason
True if the event denied type of an event records matches reason which
may be ingress, egress, interface, nosyn
asa xevent comp num
True, if the comparison of the extended event field of the event record
matches num
xip ipaddr
src xip ipaddr
dst xip ipaddr True, if the field of the translated source or destination IP address
matches ipaddr if xip is specified without src or dst both IP addresses
may match.
xport ipaddr
src xport ipaddr
dst xport ipaddr True, if the field of the translated source or destination IP address
matches ipaddr if xport is specified without src or dst both ports may
match.
xnet network/mask
src xnet network/mask
dst xnet network/mask
True if the translated source or destination IP address matches network
if mask mask is applied. if xnet is specified without src or dst both
IP addresses may match.
ingress ACL comp number
ingress ACE comp number
ingress XACE comp number
True if the comparison of the respective ingress field matches number
egress ACL comp number
True if the comparison of the egress field matches number
NEL specific filters:
nat event event True if the NEL event type of an event record matches event. event may
be add, delete
nat event comp number
True if the comparison of the NEL event type of an event records matches
number as a number.
nip ipaddr
src nip ipaddr
dst nip ipaddr True, if the field of the nat source or destination IP address matches
ipaddr if nip is specified without src or dst both IP addresses may
match.
It Cm nport Ar number
src nport number
dst nport number True, if the field of the nat source or destination port matches number
if nip is specified without src or dst both ports may match.
ingress vrf number True, if the field of the ingess vrf field of the event record matches
number
pblock start comp number
pblock step comp number
pblock end comp number
True if the comparison of the start, step or end of the NAT port block
in the event record matches number
port in pblock
src port in pblock
dst port in pblock True, if the source or destination port field matches the NAT port block
range
comp Many filter elements support the comparison with a number. The
following comparators are supported for each of those filters: =, ==, >,
<, >=, <= To prevent collisions with bash interpretion, alternative
comparators are available: EQ, LT, GT, LE, GE If comp is omitted, '=='
is assumed.
OUTPUT FORMAT
This section describes how output formats are compiled. nfdump has a lot of already pre-
defined output formats such as raw, json, csv etc. One line formats as described for option
-o can be compiled from various elements of a flow record. As a flow record can contains man
different elements it is often useful to compile an output format for spcific needs.
Format description
The output format is specified by -o “fmt: string” string contains the field tags to be
printed as well as other characters if needed. A tag starts with a % sign followed by the
field name. tags are separated by spaces from other tags. Characters or other strings, not
starting with a % sign are copied literally to the output.
Example:
-o “fmt:%ts %td %pr %sap -> %dap %pkt %byt %fl”
This is the definition of the predined format line. It adds the elements tstart duration
protocol source IP address/port followed by the literal characters -> and destination ip
address/port packets, bytes, flows counter. Depending on the task, different output formats
are required to see the required fields of a flow record. You can either extend a predefined
format or specifiy a new one at the command line.
Example: Extend the predefined format long with the the IP address of the sending router
-o “fmt:%long %ra”
Predefined formats can be extended by simply add their name with a % sign somewhere in the
format string. As described under the output option -o
Format definition
nfdump has already many formats predefined. Most of the time, these format are good enough.
Sometimes you may need different formats, which can be compiled as described above. In order
to prevent adding the same often used output format each time you run nfdump a new output
format may be define in the config file nfdump.conf The file nfdump.conf.dist contains the
definition of the already hard coded formats. These may be uncommented and changed according
to the specific needs. New formats may be added using the following sytax:
fmt.newname = “fmt:%ts %td %pr %sap -> %dap %pkt %byt %fl”
with newname any new or existing definition of output formats. Existing formats are
overwriten with the new definition.
Tag definition
The following list contains all tags, which are available to compile the output format:
%<format>
Inserts the predefined format at this position. e.g. %line
%cnt Record counter. record numbers are assigned dynamically assigned while
reading readed from file.
%nfv Netflow version.
%ts Start Time - first seen
%tfs First seen - identical to %ts
%tsr Start Time, but in fractional seconds since the epoch (1970-01-01) UNIX
format.
%te End Time - last seen
%ter End Time, in fractional seconds
%tr Time the flow was received by the collector
%trr Time the flow was received, in fractional seconds
%td Duration of flow. Displayed in ddHHMMSS.msec
%pr Transort protocol
%exp Exporter ID
%eng Engine Type/ID
%lbl Flowlabel
%sa Source Address
%da Destination Address
%sap Source Address:Port
%dap Destination Address:Port
%gsap Source Address(country code):Port
%gdap Destination Address(country code):Port
%sp Source Port
%dp Destination Port
%it ICMP-type
%ic ICMP-code
%sn Source Network, mask applied
%dn Destination Network, mask applied
%nh Next-hop IP Address
%nhb BGP Next-hop IP Address
%ra Router IP Address
%sas Source AS
%das Destination AS
%nas Next AS
%pas Previous AS
%in Input Interface num
%out Output Interface num
%pkt Packets - default input
%ipkt Input Packets
%opkt Output Packets
%byt Bytes - default input
%ibyt Input Bytes
%obyt Output Bytes
%fl Flows
%flg TCP Flags
%tos Tos - default src
%stos Src Tos
%dtos Dst Tos
%dir Direction: ingress, egress
%smk Src mask
%dmk Dst mask
%fwd Forwarding Status
%svln Src vlan label
%dvln Dst vlan label
%ismc Input Src Mac Addr
%odmc Output Dst Mac Addr
%idmc Input Dst Mac Addr
%osmc Output Src Mac Addr
%mpls1 MPLS label 1
%mpls2 MPLS label 2
%mpls3 MPLS label 3
%mpls4 MPLS label 4
%mpls5 MPLS label 5
%mpls6 MPLS label 6
%mpls7 MPLS label 7
%mpls8 MPLS label 8
%mpls9 MPLS label 9
%mpls10 MPLS label 10
%mpls MPLS labels 1-10
%bps bps - bits per second
%pps pps - packets per second
%bpp bps - Bytes per package
%sc src IP 2 letter country code
%dc dst IP 2 letter country code
%sloc src IP geo location info
%dloc dst IP geo location info
%n new line char \n
%ipl input payload
%opl ouput payload
%nbid nbar ID
%ja3 ja3 hash
%sni sni name in tls handshake
%nbnam nbar name
%odid observation domainID
%opid observation pointID
NSEL specific formats
%nfc NSEL connection ID
%evt NSEL event
%xevt NSEL extended event
%sgt NSEL Source security group tag
%msec NSEL event time in msec
%iacl NSEL ingress ACL
%eacl NSEL egress ACL
%xsa NSEL XLATE src IP address
%xda NSEL XLATE dst IP address
%xsp NSEL XLATE src port
%xdp NSEL SLATE dst port
%xsap Xlate Source Address:Port
%xdap Xlate Destination Address:Port
%uname NSEL user name
NEL/NAT specific formats
%nevt NAT event - same as %evt
%ivrf NAT ingress VRF ID
%evrf NAT egress VRF ID
%nsa NAT src IP address
%nda NAT dst IP address
%nsp NAT src port
%ndp NAT dst port
%pbstart NAT pool block start
%pbend NAT pool block end
%pbstep NAT pool block step
%pbsize NAT pool block size
Nprobe formats
%cl Client latency
%sl Server latency
%al Application latency
EXAMPLES
nfdump processes files created by any previous version of nfdump 1.6.x with some limitations
for versions < 1.6.17. In order to convert flow files to the new 1.7.x binary format use the
following command to read//write files:
% nfdump -r oldfile -w newfile
Print a statistic about the top 20 IP adresses, once sorted by flows and once by bytes
% nfdump -r flowfile -s ip/flows/bytes -n 20
Print two statistics, one about the source IP and one about the destination IP address
limited to flow with either source or destination port 443
% nfdump -r flowfile -s srcip/bytes -s dstip/bytes -n 20 'port 443'
Print a statistic about the IP pairs, which exchanged most traffic.
% nfdump -r flowfile -s record/bytes -A srcip,dstip
Print all flows in raw format with a HTTP header in the payload even if flow is not on port
80.
% nfdump -r flowfile -o raw “payload regex 'GET|POST'”
Print a statistic about all ja3 md5 sums for those flows, which a valid ja3 can be
calculated
% nfdump -r flowfile -s ja5 -n 0 'payload ja3 defined'
Aggregate all flows and write the result back to a binary file, sorted by the start time
% nfdump -r flowfile -a -Otstart -w newfile
RETURN VALUES
nfdump returns 0 on success and 255 if processing failed.
SEE ALSO
https://www.iana.org/assignments/ipfix/ipfix.xhtml
https://www.cisco.com/en/US/technologies/tk648/tk362/technologies_white_paper09186a00800a3db9.html
nfcapd(1) nfpcapd(1) sfcapd(1) geolookup(1)
BUGS
No software without bugs! Please report any bugs back to me.