DragonFly On-Line Manual Pages

NPING(1) Nping Reference Guide NPING(1)

NAME
nping - Network packet generation tool / ping utility

SYNOPSIS
nping [Options] {targets}

DESCRIPTION
Nping is an open-source tool for network packet generation, response
analysis and response time measurement. Nping allows users to generate
network packets of a wide range of protocols, letting them tune
virtually any field of the protocol headers. While Nping can be used as
a simple ping utility to detect active hosts, it can also be used as a
raw packet generator for network stack stress tests, ARP poisoning,
Denial of Service attacks, route tracing, and other purposes.

Additionally, Nping offers a special mode of operation called the "Echo
Mode", that lets users see how the generated probes change in transit,
revealing the differences between the transmitted packets and the
packets received at the other end. See section "Echo Mode" for details.

The output from Nping is a list of the packets that are being sent and
received. The level of detail depends on the options used.

A typical Nping execution is shown in Example 1. The only Nping
arguments used in this example are -c, to specify the number of times
to target each host, --tcp to specify TCP Probe Mode, -p 80,433 to
specify the target ports; and then the two target hostnames.

Example 1. A representative Nping execution

# nping -c 1 --tcp -p 80,433 scanme.nmap.org google.com

Starting Nping ( https://nmap.org/nping )
SENT (0.0120s) TCP 96.16.226.135:50091 > 64.13.134.52:80 S ttl=64 id=52072 iplen=40 seq=1077657388 win=1480
RCVD (0.1810s) TCP 64.13.134.52:80 > 96.16.226.135:50091 SA ttl=53 id=0 iplen=44 seq=4158134847 win=5840 <mss 1460>
SENT (1.0140s) TCP 96.16.226.135:50091 > 74.125.45.100:80 S ttl=64 id=13932 iplen=40 seq=1077657388 win=1480
RCVD (1.1370s) TCP 74.125.45.100:80 > 96.16.226.135:50091 SA ttl=52 id=52913 iplen=44 seq=2650443864 win=5720 <mss 1430>
SENT (2.0140s) TCP 96.16.226.135:50091 > 64.13.134.52:433 S ttl=64 id=8373 iplen=40 seq=1077657388 win=1480
SENT (3.0140s) TCP 96.16.226.135:50091 > 74.125.45.100:433 S ttl=64 id=23624 iplen=40 seq=1077657388 win=1480

The newest version of Nping can be obtained with Nmap at
https://nmap.org. The newest version of this man page is available at
https://nmap.org/book/nping-man.html.

-->
.SH "OPTIONS SUMMARY"

This options summary is printed when Nping is run with no arguments. It
helps people remember the most common options, but is no substitute for
the in-depth documentation in the rest of this manual. Some obscure
options aren't even included here.

Nping 0.7.92SVN ( https://nmap.org/nping )
Usage: nping [Probe mode] [Options] {target specification}

TARGET SPECIFICATION:
Targets may be specified as hostnames, IP addresses, networks, etc.
Ex: scanme.nmap.org, microsoft.com/24, 192.168.0.1; 10.0.*.1-24
PROBE MODES:
--tcp-connect : Unprivileged TCP connect probe mode.
--tcp : TCP probe mode.
--udp : UDP probe mode.
--icmp : ICMP probe mode.
--arp : ARP/RARP probe mode.
--tr, --traceroute : Traceroute mode (can only be used with
TCP/UDP/ICMP modes).
TCP CONNECT MODE:
-p, --dest-port <port spec> : Set destination port(s).
-g, --source-port <portnumber> : Try to use a custom source port.
TCP PROBE MODE:
-g, --source-port <portnumber> : Set source port.
-p, --dest-port <port spec> : Set destination port(s).
--seq <seqnumber> : Set sequence number.
--flags <flag list> : Set TCP flags (ACK,PSH,RST,SYN,FIN...)
--ack <acknumber> : Set ACK number.
--win <size> : Set window size.
--badsum : Use a random invalid checksum.
UDP PROBE MODE:
-g, --source-port <portnumber> : Set source port.
-p, --dest-port <port spec> : Set destination port(s).
--badsum : Use a random invalid checksum.
ICMP PROBE MODE:
--icmp-type <type> : ICMP type.
--icmp-code <code> : ICMP code.
--icmp-id <id> : Set identifier.
--icmp-seq <n> : Set sequence number.
--icmp-redirect-addr <addr> : Set redirect address.
--icmp-param-pointer <pnt> : Set parameter problem pointer.
--icmp-advert-lifetime <time> : Set router advertisement lifetime.
--icmp-advert-entry <IP,pref> : Add router advertisement entry.
--icmp-orig-time <timestamp> : Set originate timestamp.
--icmp-recv-time <timestamp> : Set receive timestamp.
--icmp-trans-time <timestamp> : Set transmit timestamp.
ARP/RARP PROBE MODE:
--arp-type <type> : Type: ARP, ARP-reply, RARP, RARP-reply.
--arp-sender-mac <mac> : Set sender MAC address.
--arp-sender-ip <addr> : Set sender IP address.
--arp-target-mac <mac> : Set target MAC address.
--arp-target-ip <addr> : Set target IP address.
IPv4 OPTIONS:
-S, --source-ip : Set source IP address.
--dest-ip <addr> : Set destination IP address (used as an
alternative to {target specification} ).
--tos <tos> : Set type of service field (8bits).
--id <id> : Set identification field (16 bits).
--df : Set Don't Fragment flag.
--mf : Set More Fragments flag.
--evil : Set Reserved / Evil flag.
--ttl <hops> : Set time to live [0-255].
--badsum-ip : Use a random invalid checksum.
--ip-options <S|R [route]|L [route]|T|U ...> : Set IP options
--ip-options <hex string> : Set IP options
--mtu <size> : Set MTU. Packets get fragmented if MTU is
small enough.
IPv6 OPTIONS:
-6, --IPv6 : Use IP version 6.
--dest-ip : Set destination IP address (used as an
alternative to {target specification}).
--hop-limit : Set hop limit (same as IPv4 TTL).
--traffic-class <class> : : Set traffic class.
--flow <label> : Set flow label.
ETHERNET OPTIONS:
--dest-mac <mac> : Set destination mac address. (Disables
ARP resolution)
--source-mac <mac> : Set source MAC address.
--ether-type <type> : Set EtherType value.
PAYLOAD OPTIONS:
--data <hex string> : Include a custom payload.
--data-string <text> : Include a custom ASCII text.
--data-length <len> : Include len random bytes as payload.
ECHO CLIENT/SERVER:
--echo-client <passphrase> : Run Nping in client mode.
--echo-server <passphrase> : Run Nping in server mode.
--echo-port <port> : Use custom <port> to listen or connect.
--no-crypto : Disable encryption and authentication.
--once : Stop the server after one connection.
--safe-payloads : Erase application data in echoed packets.
TIMING AND PERFORMANCE:
Options which take <time> are in seconds, or append 'ms' (milliseconds),
's' (seconds), 'm' (minutes), or 'h' (hours) to the value (e.g. 30m, 0.25h).
--delay <time> : Adjust delay between probes.
--rate <rate> : Send num packets per second.
MISC:
-h, --help : Display help information.
-V, --version : Display current version number.
-c, --count <n> : Stop after <n> rounds.
-e, --interface <name> : Use supplied network interface.
-H, --hide-sent : Do not display sent packets.
-N, --no-capture : Do not try to capture replies.
--privileged : Assume user is fully privileged.
--unprivileged : Assume user lacks raw socket privileges.
--send-eth : Send packets at the raw Ethernet layer.
--send-ip : Send packets using raw IP sockets.
--bpf-filter <filter spec> : Specify custom BPF filter.
OUTPUT:
-v : Increment verbosity level by one.
-v[level] : Set verbosity level. E.g: -v4
-d : Increment debugging level by one.
-d[level] : Set debugging level. E.g: -d3
-q : Decrease verbosity level by one.
-q[N] : Decrease verbosity level N times
--quiet : Set verbosity and debug level to minimum.
--debug : Set verbosity and debug to the max level.
EXAMPLES:
nping scanme.nmap.org
nping --tcp -p 80 --flags rst --ttl 2 192.168.1.1
nping --icmp --icmp-type time --delay 500ms 192.168.254.254
nping --echo-server "public" -e wlan0 -vvv
nping --echo-client "public" echo.nmap.org --tcp -p1-1024 --flags ack

SEE THE MAN PAGE FOR MANY MORE OPTIONS, DESCRIPTIONS, AND EXAMPLES

TARGET SPECIFICATION
Everything on the Nping command line that isn't an option or an option
argument is treated as a target host specification. Nping uses the same
syntax for target specifications that Nmap does. The simplest case is a
single target given by IP address or hostname.

Nping supports CIDR-style addressing. You can append /numbits to an
IPv4 address or hostname and Nping will send probes to every IP address
for which the first numbits are the same as for the reference IP or
hostname given. For example, 192.168.10.0/24 would send probes to the
256 hosts between 192.168.10.0 (binary: 11000000 10101000 00001010
00000000) and 192.168.10.255 (binary: 11000000 10101000 00001010
11111111), inclusive. 192.168.10.40/24 would ping exactly the same
targets. Given that the host scanme.nmap.org is at the IP address
64.13.134.52, the specification scanme.nmap.org/16 would send probes to
the 65,536 IP addresses between 64.13.0.0 and 64.13.255.255. The
smallest allowed value is /0, which targets the whole Internet. The
largest value is /32, which targets just the named host or IP address
because all address bits are fixed.

CIDR notation is short but not always flexible enough. For example, you
might want to send probes to 192.168.0.0/16 but skip any IPs ending
with .0 or .255 because they may be used as subnet network and
broadcast addresses. Nping supports this through octet range
addressing. Rather than specify a normal IP address, you can specify a
comma-separated list of numbers or ranges for each octet. For example,
192.168.0-255.1-254 will skip all addresses in the range that end in .0
or .255, and 192.168.3-5,7.1 will target the four addresses
192.168.3.1, 192.168.4.1, 192.168.5.1, and 192.168.7.1. Either side of
a range may be omitted; the default values are 0 on the left and 255 on
the right. Using - by itself is the same as 0-255, but remember to use
0- in the first octet so the target specification doesn't look like a
command-line option. Ranges need not be limited to the final octets:
the specifier 0-.-.13.37 will send probes to all IP addresses on the
Internet ending in .13.37. This sort of broad sampling can be useful
for Internet surveys and research.

IPv6 addresses can only be specified by their fully qualified IPv6
address or hostname. CIDR and octet ranges aren't supported for IPv6
because they are rarely useful.

Nping accepts multiple host specifications on the command line, and
they don't need to be the same type. The command nping scanme.nmap.org
192.168.0.0/8 10.0.0,1,3-7.- does what you would expect.

OPTION SPECIFICATION
Nping is designed to be very flexible and fit a wide variety of needs.
As with most command-line tools, its behavior can be adjusted using
command-line options. These general principles apply to option
arguments, unless stated otherwise.

Options that take integer numbers can accept values specified in
decimal, octal or hexadecimal base. When a number starts with 0x, it
will be treated as hexadecimal; when it simply starts with 0, it will
be treated as octal. Otherwise, Nping will assume the number has been
specified in base 10. Virtually all numbers that can be supplied from
the command line are unsigned so, as a general rule, the minimum value
is zero. Users may also specify the word random or rand to make Nping
generate a random value within the expected range.

IP addresses may be given as IPv4 addresses (e.g. 192.168.1.1), IPv6
addresses (e.g. 2001:db8:85a3::8e4c:760:7146), or hostnames, which
will be resolved using the default DNS server configured in the host
system.

Options that take MAC addresses accept the usual colon-separated 6 hex
byte format (e.g. 00:50:56:d4:01:98). Hyphens may also be used instead
of colons (e.g. 00-50-56-c0-00-08). The special word random or rand
sets a random address and the word broadcast or bcast sets
ff:ff:ff:ff:ff:ff.

GENERAL OPERATION
Unlike other ping and packet generation tools, Nping supports multiple
target host and port specifications. While this provides great
flexibility, it is not obvious how Nping handles situations where there
is more than one host and/or more than one port to send probes to. This
section explains how Nping behaves in these cases.

When multiple target hosts are specified, Nping rotates among them in
round-robin fashion. This gives slow hosts more time to send their
responses before another probe is sent to them. Ports are also
scheduled using round robin. So, unless only one port is specified,
Nping never sends two probes to the same target host and port
consecutively.

The loop around targets is the "inner loop" and the loop around ports
is the "outer loop". All targets will be sent a probe for a given port
before moving on to the next port. Between probes, Nping waits a
configurable amount of time called the "inter-probe delay", which is
controlled by the --delay option. These examples show how it works.

# nping --tcp -c 2 1.1.1.1 -p 100-102

Starting Nping ( https://nmap.org/nping )
SENT (0.0210s) TCP 192.168.1.77 > 1.1.1.1:100
SENT (1.0230s) TCP 192.168.1.77 > 1.1.1.1:101
SENT (2.0250s) TCP 192.168.1.77 > 1.1.1.1:102
SENT (3.0280s) TCP 192.168.1.77 > 1.1.1.1:100
SENT (4.0300s) TCP 192.168.1.77 > 1.1.1.1:101
SENT (5.0320s) TCP 192.168.1.77 > 1.1.1.1:102

# nping --tcp -c 2 1.1.1.1 2.2.2.2 3.3.3.3 -p 8080

Starting Nping ( https://nmap.org/nping )
SENT (0.0230s) TCP 192.168.0.21 > 1.1.1.1:8080
SENT (1.0240s) TCP 192.168.0.21 > 2.2.2.2:8080
SENT (2.0260s) TCP 192.168.0.21 > 3.3.3.3:8080
SENT (3.0270s) TCP 192.168.0.21 > 1.1.1.1:8080
SENT (4.0290s) TCP 192.168.0.21 > 2.2.2.2:8080
SENT (5.0310s) TCP 192.168.0.21 > 3.3.3.3:8080

# nping --tcp -c 1 --delay 500ms 1.1.1.1 2.2.2.2 3.3.3.3 -p 137-139

Starting Nping ( https://nmap.org/nping )
SENT (0.0230s) TCP 192.168.0.21 > 1.1.1.1:137
SENT (0.5250s) TCP 192.168.0.21 > 2.2.2.2:137
SENT (1.0250s) TCP 192.168.0.21 > 3.3.3.3:137
SENT (1.5280s) TCP 192.168.0.21 > 1.1.1.1:138
SENT (2.0280s) TCP 192.168.0.21 > 2.2.2.2:138
SENT (2.5310s) TCP 192.168.0.21 > 3.3.3.3:138
SENT (3.0300s) TCP 192.168.0.21 > 1.1.1.1:139
SENT (3.5330s) TCP 192.168.0.21 > 2.2.2.2:139
SENT (4.0330s) TCP 192.168.0.21 > 3.3.3.3:139

PROBE MODES
Nping supports a wide variety of protocols. Although in some cases
Nping can automatically determine the mode from the options used, it is
generally a good idea to specify it explicitly.

--tcp-connect (TCP Connect mode)
TCP connect mode is the default mode when a user does not have raw
packet privileges. Instead of writing raw packets as most other
modes do, Nping asks the underlying operating system to establish a
connection with the target machine and port by issuing the connect
system call. This is the same high-level system call that web
browsers, P2P clients, and most other network-enabled applications
use to establish a connection. It is part of a programming
interface known as the Berkeley Sockets API. Rather than read raw
packet responses off the wire, Nping uses this API to obtain status
information on each connection attempt. For this reason, you will
not be able to see the contents of the packets that are sent or
received but only status information about the TCP connection
establishment taking place.

--tcp (TCP mode)
TCP is the mode that lets users create and send any kind of TCP
packet. TCP packets are sent embedded in IP packets that can also
be tuned. This mode can be used for many different purposes. For
example you could try to discover open ports by sending TCP SYN
messages without completing the three-way handshake. This technique
is often referred to as half-open scanning, because you don't open
a full TCP connection. You send a SYN packet, as if you are going
to open a real connection and then wait for a response. A SYN/ACK
indicates the port is open, while a RST indicates it's closed. If
no response is received one could assume that some intermediate
network device is filtering the responses. Another use could be to
see how a remote TCP/IP stack behaves when it receives a
non-RFC-compliant packet, like one with both SYN and RST flags set.
One could also do some evil by creating custom RST packets using an
spoofed IP address with the intent of closing an active TCP
connection.

--udp (UDP mode)
UDP mode can have two different behaviours. Under normal
circumstances, it lets users create custom IP/UDP packets. However,
if Nping is run by a user without raw packet privileges and no
changes to the default protocol headers are requested, then Nping
enters the unprivileged UDP mode which basically sends UDP packets
to the specified target hosts and ports using the sendto system
call. Note that in this unprivileged mode it is not possible to see
low-level header information of the packets on the wire but only
status information about the amount of bytes that are being
transmitted and received. UDP mode can be used to interact with any
UDP-based server. Examples are DNS servers, streaming servers,
online gaming servers, and port knocking/single-packet
authorization daemons.

--icmp (ICMP mode)
ICMP mode is the default mode when the user runs Nping with raw
packet privileges. Any kind of ICMP message can be created. The
default ICMP type is Echo, i.e., ping. ICMP mode can be used for
many different purposes, from a simple request for a timestamp or a
netmask to the transmission of fake destination unreachable
messages, custom redirects, and router advertisements.

--arp (ARP/RARP mode)
ARP lets you create and send a few different ARP-related packets.
These include ARP, RARP, DRARP, and InARP requests and replies.
This mode can ban be used to perform low-level host discovery, and
conduct ARP-cache poisoning attacks.

--traceroute (Traceroute mode)
Traceroute is not a mode by itself but a complement to TCP, UDP,
and ICMP modes. When this option is specified Nping will set the IP
TTL value of the first probe to 1. When the next router receives
the packet it will drop it due to the expiration of the TTL and it
will generate an ICMP destination unreachable message. The next
probe will have a TTL of 2 so now the first router will forward the
packet while the second router will be the one that drops the
packet and generates the ICMP message. The third probe will have a
TTL value of 3 and so on. By examining the source addresses of all
those ICMP Destination Unreachable messages it is possible to
determine the path that the probes take until they reach their
final destination.

TCP CONNECT MODE
-p port_spec, --dest-port port_spec (Target ports)
This option specifies which ports you want to try to connect to. It
can be a single port, a comma-separated list of ports (e.g.
80,443,8080), a range (e.g. 1-1023), and any combination of those
(e.g. 21-25,80,443,1024-2048). The beginning and/or end values of
a range may be omitted, causing Nping to use 1 and 65535,
respectively. So you can specify -p- to target ports from 1 through
65535. Using port zero is allowed if you specify it explicitly.

-g portnumber, --source-port portnumber (Spoof source port)
This option asks Nping to use the specified port as source port for
the TCP connections. Note that this might not work on all systems
or may require root privileges. Specified value must be an integer
in the range [0-65535].

TCP MODE
-p port_spec, --dest-port port_spec (Target ports)
This option specifies which destination ports you want to send
probes to. It can be a single port, a comma-separated list of ports
(e.g. 80,443,8080), a range (e.g. 1-1023), and any combination of
those (e.g. 21-25,80,443,1024-2048). The beginning and/or end
values of a range may be omitted, causing Nping to use 1 and 65535,
respectively. So you can specify -p- to target ports from 1 through
65535. Using port zero is allowed if you specify it explicitly.

--seq seqnumber (Sequence Number)
Specifies the TCP sequence number. In SYN packets this is the
initial sequence number (ISN). In a normal transmission this
corresponds to the sequence number of the first byte of data in the
segment. seqnumber must be a number in the range [0-4294967295].

--flags flags (TCP Flags)
This option specifies which flags should be set in the TCP packet.
flags may be specified in three different ways:

1. As a comma-separated list of flags, e.g. --flags syn,ack,rst

2. As a list of one-character flag initials, e.g. --flags SAR
tells Nping to set flags SYN, ACK, and RST.

3. As an 8-bit hexadecimal number, where the supplied number is
the exact value that will be placed in the flags field of the
TCP header. The number should start with the prefix 0x and
should be in the range [0x00-0xFF], e.g. --flags 0x20 sets the
URG flag as 0x20 corresponds to binary 00100000 and the URG
flag is represented by the third bit.

There are 8 possible flags to set: CWR, ECN, URG, ACK, PSH, RST,
SYN, and FIN. The special value ALL means to set all flags. NONE
means to set no flags. It is important that if you don't want any
flag to be set, you request it explicitly because in some cases the
SYN flag may be set by default. Here is a brief description of the
meaning of each flag:

CWR (Congestion Window Reduced)
Set by an ECN-Capable sender when it reduces its congestion
window (due to a retransmit timeout, a fast retransmit or in
response to an ECN notification.

ECN (Explicit Congestion Notification)
During the three-way handshake it indicates that sender is
capable of performing explicit congestion notification.
Normally it means that a packet with the IP Congestion
Experienced flag set was received during normal transmission.
See RFC 3168 for more information.

URG (Urgent)
Segment is urgent and the urgent pointer field carries valid
information.

ACK (Acknowledgement)
The segment carries an acknowledgement and the value of the
acknowledgement number field is valid and contains the next
sequence number that is expected from the receiver.

PSH (Push)
The data in this segment should be immediately pushed to the
application layer on arrival.

RST (Reset)
There was some problem and the sender wants to abort the
connection.

SYN (Synchronize)
The segment is a request to synchronize sequence numbers and
establish a connection. The sequence number field contains the
sender's initial sequence number.

FIN (Finish)
The sender wants to close the connection.

--win size (Window Size)
Specifies the TCP window size, this is, the number of octets the
sender of the segment is willing to accept from the receiver at one
time. This is usually the size of the reception buffer that the OS
allocates for a given connection. size must be a number in the
range [0-65535].

--badsum (Invalid Checksum)
Asks Nping to use an invalid TCP checksum for the packets sent to
target hosts. Since virtually all host IP stacks properly drop
these packets, any responses received are likely coming from a
firewall or an IDS that didn't bother to verify the checksum. For
more details on this technique, see https://nmap.org/p60-12.html.

UDP MODE
-p port_spec, --dest-port port_spec (Target ports)
This option specifies which ports you want UDP datagrams to be sent
to. It can be a single port, a comma-separated list of ports (e.g.
80,443,8080), a range (e.g. 1-1023), and any combination of those
(e.g. 21-25,80,443,1024-2048). The beginning and/or end values of
a range may be omitted, causing Nping to use 1 and 65535,
respectively. So you can specify -p- to target ports from 1 through
65535. Using port zero is allowed if you specify it explicitly.

-g portnumber, --source-port portnumber (Spoof source port)
This option asks Nping to use the specified port as source port for
the transmitted datagrams. Note that this might not work on all
systems or may require root privileges. Specified value must be an
integer in the range [0-65535].

--badsum (Invalid Checksum)
Asks Nping to use an invalid UDP checksum for the packets sent to
target hosts. Since virtually all host IP stacks properly drop
these packets, any responses received are likely coming from a
firewall or an IDS that didn't bother to verify the checksum. For
more details on this technique, see https://nmap.org/p60-12.html.

ICMP MODE
--icmp-type type (ICMP type)
This option specifies which type of ICMP messages should be
generated. type can be supplied in two different ways. You can use
the official type numbers assigned by IANA[1] (e.g. --icmp-type 8
for ICMP Echo Request), or you can use any of the mnemonics listed
in the section called "ICMP Types".

--icmp-code code (ICMP code)
This option specifies which ICMP code should be included in the
generated ICMP messages. code can be supplied in two different
ways. You can use the official code numbers assigned by IANA[1]
(e.g. --icmp-code 1 for Fragment Reassembly Time Exceeded), or you
can use any of the mnemonics listed in the section called "ICMP
Codes".

--icmp-id id (ICMP identifier)
This option specifies the value of the identifier used in some of
the ICMP messages. In general it is used to match request and reply
messages. id must be a number in the range [0-65535].

--icmp-seq seq (ICMP sequence)
This option specifies the value of the sequence number field used
in some ICMP messages. In general it is used to match request and
reply messages. id must be a number in the range [0-65535].

--icmp-redirect-addr addr (ICMP Redirect address)
This option sets the address field in ICMP Redirect messages. In
other words, it sets the IP address of the router that should be
used when sending IP datagrams to the original destination. addr
can be either an IPv4 address or a hostname.

--icmp-param-pointer pointer (ICMP Parameter Problem pointer)
This option specifies the pointer that indicates the location of
the problem in ICMP Parameter Problem messages. pointer should be
a number in the range [0-255]. Normally this option is only used
when ICMP code is set to 0 ("Pointer indicates the error").

--icmp-advert-lifetime ttl (ICMP Router Advertisement Lifetime)
This option specifies the router advertisement lifetime, this is,
the number of seconds the information carried in an ICMP Router
Advertisement can be considered valid for. ttl must be a positive
integer in the range [0-65535].

--icmp-advert-entry addr,pref (ICMP Router Advertisement Entry)
This option adds a Router Advertisement entry to an ICMP Router
Advertisement message. The parameter must be two values separated
by a comma. addr is the router's IP and can be specified either as
an IP address in dot-decimal notation or as a hostname. pref is
the preference level for the specified IP. It must be a number in
the range [0-4294967295]. An example is --icmp-advert-entry
192.168.128.1,3.

--icmp-orig-time timestamp (ICMP Originate Timestamp)
This option sets the Originate Timestamp in ICMP Timestamp
messages. The Originate Timestamp is expressed as the number of
milliseconds since midnight UTC and it corresponds to the time the
sender last touched the Timestamp message before its transmission.
timestamp can be specified as a regular time (e.g. 10s, 3h,
1000ms), or the special string now. You can add or subtract values
from now, for example --icmp-orig-time now-2s, --icmp-orig-time
now+1h, --icmp-orig-time now+200ms.

--icmp-recv-time timestamp (ICMP Receive Timestamp)
This option sets the Receive Timestamp in ICMP Timestamp messages.
The Receive Timestamp is expressed as the number of milliseconds
since midnight UTC and it corresponds to the time the echoer first
touched the Timestamp message on receipt. timestamp is as with
--icmp-orig-time.

--icmp-trans-time timestamp (ICMP Transmit Timestamp)
This option sets the Transmit Timestamp in ICMP Timestamp messages.
The Transmit Timestamp is expressed as the number of milliseconds
since midnight UTC and it corresponds to the time the echoer last
touched the Timestamp message before its transmission. timestamp
is as with --icmp-orig-time.

ICMP Types
These identifiers may be used as mnemonics for the ICMP type numbers
given to the --icmp-type option. In general there are three forms of
each identifier: the full name (e.g. destination-unreachable), the
short name (e.g. dest-unr), or the initials (e.g. du). In ICMP types
that request something, the word "request" is omitted.

echo-reply, echo-rep, er
Echo Reply (type 0). This message is sent in response to an Echo
Request message.

destination-unreachable, dest-unr, du
Destination Unreachable (type 3). This message indicates that a
datagram could not be delivered to its destination.

source-quench, sour-que, sq
Source Quench (type 4). This message is used by a congested IP
device to tell other device that is sending packets too fast and
that it should slow down.

redirect, redi, r
Redirect (type 5). This message is normally used by routers to
inform a host that there is a better route to use for sending
datagrams. See also the --icmp-redirect-addr option.

echo-request, echo, e
Echo Request (type 8). This message is used to test the
connectivity of another device on a network.

router-advertisement, rout-adv, ra
Router Advertisement (type 9). This message is used by routers to
let hosts know of their existence and capabilities. See also the
--icmp-advert-lifetime option.

router-solicitation, rout-sol, rs
Router Solicitation (type 10). This message is used by hosts to
request Router Advertisement messages from any listening routers.

time-exceeded, time-exc, te
Time Exceeded (type 11). This message is generated by some
intermediate device (normally a router) to indicate that a datagram
has been discarded before reaching its destination because the IP
TTL expired.

parameter-problem, member-pro, pp
Parameter Problem (type 12). This message is used when a device
finds a problem with a parameter in an IP header and it cannot
continue processing it. See also the --icmp-param-pointer option.

timestamp, time, tm
Timestamp Request (type 13). This message is used to request a
device to send a timestamp value for propagation time calculation
and clock synchronization. See also the --icmp-orig-time,
--icmp-recv-time, and --icmp-trans-time.

timestamp-reply, time-rep, tr
Timestamp Reply (type 14). This message is sent in response to a
Timestamp Request message.

information, info, i
Information Request (type 15). This message is now obsolete but it
was originally used to request configuration information from
another device.

information-reply, info-rep, ir
Information Reply (type 16). This message is now obsolete but it
was originally sent in response to an Information Request message
to provide configuration information.

mask-request, mask, m
Address Mask Request (type 17). This message is used to ask a
device to send its subnet mask.

mask-reply, mask-rep, mr
Address Mask Reply (type 18). This message contains a subnet mask
and is sent in response to a Address Mask Request message.

traceroute, trace, tc
Traceroute (type 30). This message is normally sent by an
intermediate device when it receives an IP datagram with a
traceroute option. ICMP Traceroute messages are still experimental,
see RFC 1393 for more information.

ICMP Codes
These identifiers may be used as mnemonics for the ICMP code numbers
given to the --icmp-code option. They are listed by the ICMP type they
correspond to.

Destination Unreachable

network-unreachable, netw-unr, net
Code 0. Datagram could not be delivered to its destination
network (probably due to some routing problem).

host-unreachable, host-unr, host
Code 1. Datagram was delivered to the destination network but
it was impossible to reach the specified host (probably due to
some routing problem).

protocol-unreachable, prot-unr, proto
Code 2. The protocol specified in the Protocol field of the IP
datagram is not supported by the host to which the datagram was
delivered.

port-unreachable, port-unr, port
Code 3. The TCP/UDP destination port was invalid.

needs-fragmentation, need-fra, frag
Code 4. Datagram had the DF bit set but it was too large for
the MTU of the next physical network so it had to be dropped.

source-route-failed, sour-rou, routefail
Code 5. IP datagram had a Source Route option but a router
couldn't pass it to the next hop.

network-unknown, netw-unk, net?
Code 6. Destination network is unknown. This code is never
used. Instead, Network Unreachable is used.

host-unknown, host-unk, host?
Code 7. Specified host is unknown. Usually generated by a
router local to the destination host to inform of a bad
address.

host-isolated, host-iso, isolated
Code 8. Source Host Isolated. Not used.

network-prohibited, netw-pro, !net
Code 9. Communication with destination network is
administratively prohibited (source device is not allowed to
send packets to the destination network).

host-prohibited, host-pro, !host
Code 10. Communication with destination host is
administratively prohibited. (The source device is allowed to
send packets to the destination network but not to the
destination device.)

network-tos, unreachable-network-tos, netw-tos, tosnet
Code 11. Destination network unreachable because it cannot
provide the type of service specified in the IP TOS field.

host-tos, unreachable-host-tos, toshost
Code 12. Destination host unreachable because it cannot provide
the type of service specified in the IP TOS field.

communication-prohibited, comm-pro, !comm
Code 13. Datagram could not be forwarded due to filtering that
blocks the message based on its contents.

host-precedence-violation, precedence-violation, prec-vio,
violation
Code 14. Precedence value in the IP TOS field is not permitted.

precedence-cutoff, prec-cut, cutoff
Code 15. Precedence value in the IP TOS field is lower than the
minimum allowed for the network.

Redirect

redirect-network, redi-net, net
Code 0. Redirect all future datagrams with the same destination
network as the original datagram, to the router specified in
the Address field. The use of this code is prohibited by RFC
1812.

redirect-host, redi-host, host
Code 1. Redirect all future datagrams with the same destination
host as the original datagram, to the router specified in the
Address field.

redirect-network-tos, redi-ntos, redir-ntos
Code 2. Redirect all future datagrams with the same destination
network and IP TOS value as the original datagram, to the
router specified in the Address field. The use of this code is
prohibited by RFC 1812.

redirect-host-tos, redi-htos, redir-htos
Code 3. Redirect all future datagrams with the same destination
host and IP TOS value as the original datagram, to the router
specified in the Address field.

Router Advertisement

normal-advertisement, norm-adv, normal, zero, default, def
Code 0. Normal router advertisement. In Mobile IP: Mobility
agent can act as a router for IP datagrams not related to
mobile nodes.

not-route-common-traffic, not-rou, mobile-ip, !route,
!commontraffic
Code 16. Used for Mobile IP. The mobility agent does not route
common traffic. All foreign agents must forward to a default
router any datagrams received from a registered mobile node

Time Exceeded

ttl-exceeded-in-transit, ttl-exc, ttl-transit
Code 0. IP Time To Live expired during transit.

fragment-reassembly-time-exceeded, frag-exc, frag-time
Code 1. Fragment reassembly time has been exceeded.

Parameter Problem

pointer-indicates-error, poin-ind, pointer
Code 0. The pointer field indicates the location of the
problem. See the --icmp-param-pointer option.

missing-required-option, miss-option, option-missing
Code 1. IP datagram was expected to have an option that is not
present.

bad-length, bad-len, badlen
Code 2. The length of the IP datagram is incorrect.

ARP MODE
--arp-type type (ICMP Type)
This option specifies which type of ARP messages should be
generated. type can be supplied in two different ways. You can use
the official numbers assigned by IANA[2] (e.g. --arp-type 1 for
ARP Request), or you can use one of the mnemonics from the section
called "ARP Types".

--arp-sender-mac mac (Sender MAC address)
This option sets the Sender Hardware Address field of the ARP
header. Although ARP supports many types of link layer addresses,
currently Nping only supports MAC addresses. mac must be specified
using the traditional MAC notation (e.g. 00:0a:8a:32:f4:ae). You
can also use hyphens as separators (e.g. 00-0a-8a-32-f4-ae).

--arp-sender-ip addr (Sender IP address)
This option sets the Sender IP field of the ARP header. addr can
be given as an IPv4 address or a hostname.

--arp-target-mac mac (target MAC address)
This option sets the Target Hardware Address field of the ARP
header.

--arp-target-ip addr (target ip address)
This option sets the Target IP field of the ARP header.

ARP Types
These identifiers may be used as mnemonics for the ARP type numbers
given to the --arp-type option.

arp-request, arp, a
ARP Request (type 1). ARP requests are used to translate network
layer addresses (normally IP addresses) to link layer addresses
(usually MAC addresses). Basically, and ARP request is a
broadcasted message that asks the host in the same network segment
that has a given IP address to provide its MAC address.

arp-reply, arp-rep, ar
ARP Reply (type 2). An ARP reply is a message that a host sends in
response to an ARP request to provide its link layer address.

rarp-request, rarp, r
RARP Requests (type 3). RARP requests are used to translate a link
layer address (normally a MAC address) to a network layer address
(usually an IP address). Basically a RARP request is a broadcasted
message sent by a host that wants to know his own IP address
because it doesn't have any. It was the first protocol designed to
solve the bootstrapping problem. However, RARP is now obsolete and
DHCP is used instead. For more information about RARP see RFC 903.

rarp-reply, rarp-rep, rr
RARP Reply (type 4). A RARP reply is a message sent in response to
a RARP request to provide an IP address to the host that sent the
RARP request in the first place.

drarp-request, drarp, d
Dynamic RARP Request (type 5). Dynamic RARP is an extension to RARP
used to obtain or assign a network layer address from a fixed link
layer address. DRARP was used mainly in Sun Microsystems platforms
in the late 90's but now it's no longer used. See RFC 1931 for more
information.

drarp-reply, drarp-rep, dr
Dynamic RARP Reply (type 6). A DRARP reply is a message sent in
response to a RARP request to provide network layer address.

drarp-error, drarp-err, de
DRARP Error (type 7). DRARP Error messages are usually sent in
response to DRARP requests to inform of some error. In DRARP Error
messages, the Target Protocol Address field is used to carry an
error code (usually in the first byte). The error code is intended
to tell why no target protocol address is being returned. For more
information see RFC 1931.

inarp-request, inarp, i
Inverse ARP Request (type 8). InARP requests are used to translate
a link layer address to a network layer address. It is similar to
RARP request but in this case, the sender of the InARP request
wants to know the network layer address of another node, not its
own address. InARP is mainly used in Frame Relay and ATM networks.
For more information see RFC 2390.

inarp-reply, inarp-rep, ir
Inverse ARP Reply (type 9). InARP reply messages are sent in
response to InARP requests to provide the network layer address
associated with the host that has a given link layer address.

arp-nak, an
ARP NAK (type 10). ARP NAK messages are an extension to the ATMARP
protocol and they are used to improve the robustness of the ATMARP
server mechanism. With ARP NAK, a client can determine the
difference between a catastrophic server failure and an ATMARP
table lookup failure. See RFC 1577 for more information.

IPV4 OPTIONS
-S addr, --source-ip addr (Source IP Address)
Sets the source IP address. This option lets you specify a custom
IP address to be used as source IP address in sent packets. This
allows spoofing the sender of the packets. addr can be an IPv4
address or a hostname.

--dest-ip addr (Destination IP Address)
Adds a target to Nping's target list. This option is provided for
consistency but its use is deprecated in favor of plain target
specifications. See the section called "TARGET SPECIFICATION".

--tos tos (Type of Service)
Sets the IP TOS field. The TOS field is used to carry information
to provide quality of service features. It is normally used to
support a technique called Differentiated Services. See RFC 2474
for more information. tos must be a number in the range [0-255].

--id id (Identification)
Sets the IPv4 Identification field. The Identification field is a
16-bit value that is common to all fragments belonging to a
particular message. The value is used by the receiver to reassemble
the original message from the fragments received. id must be a
number in the range [0-65535].

--df (Don't Fragment)
Sets the Don't Fragment bit in sent packets. When an IP datagram
has its DF flag set, intermediate devices are not allowed to
fragment it so if it needs to travel across a network with a MTU
smaller that datagram length the datagram will have to be dropped.
Normally an ICMP Destination Unreachable message is generated and
sent back to the sender.

--mf (More Fragments)
Sets the More Fragments bit in sent packets. The MF flag is set to
indicate the receiver that the current datagram is a fragment of
some larger datagram. When set to zero it indicates that the
current datagram is either the last fragment in the set or that it
is the only fragment.

--evil (Reserved / Evil)
Sets the Reserved / Evil bit in sent packets. The Evil flag helps
firewalls and other network security systems to distinguish between
datagrams that have malicious intent and those that are merely
unusual. When set, it indicates that the datagram has evil intent,
instructing insecure systems to succumb. Setting it to zero
indicates no evil intent. The option is implied if environmental
variable SCRIPT_KIDDIE is set to a non-zero value.

--ttl hops (Time To Live)
Sets the IPv4 Time-To-Live (TTL) field in sent packets to the given
value. The TTL field specifies how long the datagram is allowed to
exist on the network. It was originally intended to represent a
number of seconds but it actually represents the number of hops a
packet can traverse before being dropped. The TTL tries to avoid a
situation in which undeliverable datagrams keep being forwarded
from one router to another endlessly. hops must be a number in the
range [0-255].

--badsum-ip (Invalid IP checksum)
Asks Nping to use an invalid IP checksum for packets sent to target
hosts. Note that some systems (like most Linux kernels), may fix
the checksum before placing the packet on the wire, so even if
Nping shows the incorrect checksum in its output, the packets may
be transparently corrected by the kernel.

--ip-options R|S [route]|L [route]|T|U ..., --ip-options hex string (IP
Options)
The IP protocol offers several options which may be placed in
packet headers. Unlike the ubiquitous TCP options, IP options are
rarely seen due to practicality and security concerns. In fact,
many Internet routers block the most dangerous options such as
source routing. Yet options can still be useful in some cases for
determining and manipulating the network route to target machines.
For example, you may be able to use the record route option to
determine a path to a target even when more traditional
traceroute-style approaches fail. Or if your packets are being
dropped by a certain firewall, you may be able to specify a
different route with the strict or loose source routing options.

The most powerful way to specify IP options is to simply pass in
hexadecimal data as the argument to --ip-options. Precede each hex
byte value with \x. You may repeat certain characters by following
them with an asterisk and then the number of times you wish them to
repeat. For example, \x01\x07\x04\x00*4 is the same as
\x01\x07\x04\x00\x00\x00\x00.

Note that if you specify a number of bytes that is not a multiple
of four, an incorrect IP header length will be set in the IP
packet. The reason for this is that the IP header length field can
only express multiples of four. In those cases, the length is
computed by dividing the header length by 4 and rounding down. This
will affect the way the header that follows the IP header is
interpreted, showing bogus information in Nping or in the output of
any sniffer. Although this kind of situation might be useful for
some stack stress tests, users would normally want to specify
explicit padding, so the correct header length is set.

Nping also offers a shortcut mechanism for specifying options.
Simply pass the letter R, T, or U to request record-route,
record-timestamp, or both options together, respectively. Loose or
strict source routing may be specified with an L or S followed by a
space and then a space-separated list of IP addresses.

For more information and examples of using IP options with Nping,
see the mailing list post at https://seclists.org/nmap-
dev/2006/q3/0052.html.

--mtu size (Maximum Transmission Unit)
This option sets a fictional MTU in Nping so IP datagrams larger
than size are fragmented before transmission. size must be
specified in bytes and corresponds to the number of octets that can
be carried on a single link-layer frame.

IPV6 OPTIONS
-6, --ipv6 (Use IPv6)
Tells Nping to use IP version 6 instead of the default IPv4. It is
generally a good idea to specify this option as early as possible
in the command line so Nping can parse it soon and know in advance
that the rest of the parameters refer to IPv6. The command syntax
is the same as usual except that you also add the -6 option. Of
course, you must use IPv6 syntax if you specify an address rather
than a hostname. An address might look like
3ffe:7501:4819:2000:210:f3ff:fe03:14d0, so hostnames are
recommended.

While IPv6 hasn't exactly taken the world by storm, it gets
significant use in some (usually Asian) countries and most modern
operating systems support it. To use Nping with IPv6, both the
source and target of your packets must be configured for IPv6. If
your ISP (like most of them) does not allocate IPv6 addresses to
you, free tunnel brokers are widely available and work fine with
Nping. You can use the free IPv6 tunnel broker service at
http://www.tunnelbroker.net.

Please note that IPv6 support is still highly experimental and many
modes and options may not work with it.

-S addr, --source-ip addr (Source IP Address)
Sets the source IP address. This option lets you specify a custom
IP address to be used as source IP address in sent packets. This
allows spoofing the sender of the packets. addr can be an IPv6
address or a hostname.

--flow label (Flow Label)
Sets the IPv6 Flow Label. The Flow Label field is 20 bits long and
is intended to provide certain quality-of-service properties for
real-time datagram delivery. However, it has not been widely
adopted, and not all routers or endpoints support it. Check RFC
2460 for more information. label must be an integer in the range
[0-1048575].

--traffic-class class (Traffic Class)
Sets the IPv6 Traffic Class. This field is similar to the TOS field
in IPv4, and is intended to provide the Differentiated Services
method, enabling scalable service discrimination in the Internet
without the need for per-flow state and signaling at every hop.
Check RFC 2474 for more information. class must be an integer in
the range [0-255].

--hop-limit hops (Hop Limit)

Sets the IPv6 Hop Limit field in sent packets to the given value.
The Hop Limit field specifies how long the datagram is allowed to
exist on the network. It represents the number of hops a packet can
traverse before being dropped. As with the TTL in IPv4, IPv6 Hop
Limit tries to avoid a situation in which undeliverable datagrams
keep being forwarded from one router to another endlessly. hops
must be a number in the range [0-255].

ETHERNET OPTIONS
In most cases Nping sends packets at the raw IP level. This means that
Nping creates its own IP packets and transmits them through a raw
socket. However, in some cases it may be necessary to send packets at
the raw Ethernet level. This happens, for example, when Nping is run
under Windows (as Microsoft has disabled raw socket support since
Windows XP SP2), or when Nping is asked to send ARP packets. Since in
some cases it is necessary to construct ethernet frames, Nping offers
some options to manipulate the different fields.

--dest-mac mac (Ethernet Destination MAC Address)
This option sets the destination MAC address that should be set in
outgoing Ethernet frames. This is useful in case Nping can't
determine the next hop's MAC address or when you want to route
probes through a router other than the configured default gateway.
The MAC address should have the usual format of six colon-separated
bytes, e.g. 00:50:56:d4:01:98. Alternatively, hyphens may be used
instead of colons. Use the word random or rand to generate a random
address, and broadcast or bcast to use ff:ff:ff:ff:ff:ff. If you
set up a bogus destination MAC address your probes may not reach
the intended targets.

--source-mac mac (Ethernet Source MAC Address)
This option sets the source MAC address that should be set in
outgoing Ethernet frames. This is useful in case Nping can't
determine your network interface MAC address or when you want to
inject traffic into the network while hiding your network card's
real address. The syntax is the same as for --dest-mac. If you set
up a bogus source MAC address you may not receive probe replies.

--ether-type type (Ethertype)
This option sets the Ethertype field of the ethernet frame. The
Ethertype is used to indicate which protocol is encapsulated in the
payload. type can be supplied in two different ways. You can use
the official numbers listed by the IEEE[3] (e.g. --ether-type
0x0800 for IP version 4), or one of the mnemonics from the section
called "Ethernet Types".

Ethernet Types
These identifiers may be used as mnemonics for the Ethertype numbers
given to the --arp-type option.

ipv4, ip, 4
Internet Protocol version 4 (type 0x0800).

ipv6, 6
Internet Protocol version 6 (type 0x86DD).

arp
Address Resolution Protocol (type 0x0806).

rarp
Reverse Address Resolution Protocol (type 0x8035).

frame-relay, frelay, fr
Frame Relay (type 0x0808).

ppp
Point-to-Point Protocol (type 0x880B).

gsmp
General Switch Management Protocol (type 0x880C).

mpls
Multiprotocol Label Switching (type 0x8847).

mps-ual, mps
Multiprotocol Label Switching with Upstream-assigned Label (type
0x8848).

mcap
Multicast Channel Allocation Protocol (type 0x8861).

pppoe-discovery, pppoe-d
PPP over Ethernet Discovery Stage (type 0x8863).

pppoe-session, pppoe-s
PPP over Ethernet Session Stage (type 0x8864).

ctag
Customer VLAN Tag Type (type 0x8100).

epon
Ethernet Passive Optical Network (type 0x8808).

pbnac
Port-based network access control (type 0x888E).

stag
Service VLAN tag identifier (type 0x88A8).

ethexp1
Local Experimental Ethertype 1 (type 0x88B5).

ethexp2
Local Experimental Ethertype 2 (type 0x88B6).

ethoui
OUI Extended Ethertype (type 0x88B7).

preauth
Pre-Authentication (type 0x88C7).

lldp
Link Layer Discovery Protocol (type 0x88CC).

mac-security, mac-sec, macsec
Media Access Control Security (type 0x88E5).

mvrp
Multiple VLAN Registration Protocol (type 0x88F5).

mmrp
Multiple Multicast Registration Protocol (type 0x88F6).

frrr
Fast Roaming Remote Request (type 0x890D).

PAYLOAD OPTIONS
--data hex string (Append custom binary data to sent packets)
This option lets you include binary data as payload in sent
packets. hex string may be specified in any of the following
formats: 0xAABBCCDDEEFF..., AABBCCDDEEFF... or
\xAA\xBB\xCC\xDD\xEE\xFF.... Examples of use are --data 0xdeadbeef
and --data \xCA\xFE\x09. Note that if you specify a number like
0x00ff no byte-order conversion is performed. Make sure you specify
the information in the byte order expected by the receiver.

--data-string string (Append custom string to sent packets)
This option lets you include a regular string as payload in sent
packets. string can contain any string. However, note that some
characters may depend on your system's locale and the receiver may
not see the same information. Also, make sure you enclose the
string in double quotes and escape any special characters from the
shell. Example: --data-string "Jimmy Jazz...".

--data-length len (Append random data to sent packets)
This option lets you include len random bytes of data as payload in
sent packets. len must be an integer in the range [0-65400].
However, values higher than 1400 are not recommended because it may
not be possible to transmit packets due to network MTU limitations.

ECHO MODE
The "Echo Mode" is a novel technique implemented by Nping which lets
users see how network packets change in transit, from the host where
they originated to the target machine. Basically, the Echo mode turns
Nping into two different pieces: the Echo server and the Echo client.
The Echo server is a network service that has the ability to capture
packets from the network and send a copy ("echo them") to the
originating client through a side TCP channel. The Echo client is the
part that generates such network packets, transmits them to the server,
and receives their echoed version through a side TCP channel that it
has previously established with the Echo server.

This scheme lets the client see the differences between the packets
that it sends and what is actually received by the server. By having
the server send back copies of the received packets through the side
channel, things like NAT devices become immediately apparent to the
client because it notices the changes in the source IP address (and
maybe even source port). Other devices like those that perform traffic
shaping, changing TCP window sizes or adding TCP options transparently
between hosts, turn up too.

The Echo mode is also useful for troubleshooting routing and firewall
issues. Among other things, it can be used to determine if the traffic
generated by the Nping client is being dropped in transit and never
gets to its destination or if the responses are the ones that don't get
back to it.

Internally, client and server communicate over an encrypted and
authenticated channel, using the Nping Echo Protocol (NEP), whose
technical specification can be found in
https://nmap.org/svn/nping/docs/EchoProtoRFC.txt

The following paragraphs describe the different options available in
Nping's Echo mode.

--ec passphrase, --echo-client passphrase (Run Echo client)
This option tells Nping to run as an Echo client. passphrase is a
sequence of ASCII characters that is used used to generate the
cryptographic keys needed for encryption and authentication in a
given session. The passphrase should be a secret that is also known
by the server, and it may contain any number of printable ASCII
characters. Passphrases that contain whitespace or special
characters must be enclosed in double quotes.

When running Nping as an Echo client, most options from the regular
raw probe modes apply. The client may be configured to send
specific probes using flags like --tcp, --icmp or --udp. Protocol
header fields may be manipulated normally using the appropriate
options (e.g. --ttl, --seq, --icmp-type, etc.). The only
exceptions are ARP-related flags, which are not supported in Echo
mode, as protocols like ARP are closely related to the data link
layer and its probes can't pass through different network segments.

--es passphrase, --echo-server passphrase (Run Echo server)
This option tells Nping to run as an Echo server. passphrase is a
sequence of ASCII characters that is used used to generate the
cryptographic keys needed for encryption and authentication in a
given session. The passphrase should be a secret that is also known
by the clients, and it may contain any number of printable ASCII
characters. Passphrases that contain whitespace or special
characters must be enclosed in double quotes. Note that although it
is not recommended, it is possible to use empty passphrases,
supplying --echo-server "". However, if what you want is to set up
an open Echo server, it is better to use option --no-crypto. See
below for details.

--ep port, --echo-port port (Set Echo TCP port number)
This option asks Nping to use the specified TCP port number for the
Echo side channel connection. If this option is used with
--echo-server, it specifies the port on which the server listens
for connections. If it is used with --echo-client, it specifies the
port to connect to on the remote host. By default, port number 9929
is used.

--nc, --no-crypto (Disable encryption and authentication)
This option asks Nping not to use any cryptographic operations
during an Echo session. In practical terms, this means that the
Echo side channel session data will be transmitted in the clear,
and no authentication will be performed by the server or client
during the session establishment phase. When --no-crypto is used,
the passphrase supplied with --echo-server or --echo-client is
ignored.

This option must be specified if Nping was compiled without openSSL
support. Note that, for technical reasons, a passphrase still needs
to be supplied after the --echo-client or --echo-server flags, even
though it will be ignored.

The --no-crypto flag might be useful when setting up a public Echo
server, because it allows users to connect to the Echo server
without the need for any passphrase or shared secret. However, it
is strongly recommended to not use --no-crypto unless absolutely
necessary. Public Echo servers should be configured to use the
passphrase "public" or the empty passphrase (--echo-server "") as
the use of cryptography does not only provide confidentiality and
authentication but also message integrity.

--once (Serve one client and quit)
This option asks the Echo server to quit after serving one client.
This is useful when only a single Echo session wants to be
established as it eliminates the need to access the remote host to
shutdown the server.

--safe-payloads (Zero application data before echoing a packet)
This option asks the Echo server to erase any application layer
data found in client packets before echoing them. When the option
is enabled, the Echo server parses the packets received from Echo
clients and tries to determine if they contain data beyond the
transport layer. If such data is found, it is overwritten with
zeroes before transmitting the packets to the appropriate Echo
client.

Echo servers can handle multiple simultaneous clients running
multiple echo sessions in parallel. In order to determine which
packet needs to be echoed to which client and through which
session, the Echo server uses an heuristic algorithm. Although we
have taken every security measure that we could think of to prevent
that a client receives an echoed packet that it did not generate,
there is always a risk that our algorithm makes a mistake and
delivers a packet to the wrong client. The --safe-payloads option
is useful for public echo servers or critical deployments where
that kind of mistake cannot be afforded.

The following examples illustrate how Nping's Echo mode can be used to
discover intermediate devices.

Example 2. Discovering NAT devices

# nping --echo-client "public" echo.nmap.org --udp

Starting Nping ( https://nmap.org/nping )
SENT (1.0970s) UDP 10.1.20.128:53 > 178.79.165.17:40125 ttl=64 id=32523 iplen=28
CAPT (1.1270s) UDP 80.38.10.21:45657 > 178.79.165.17:40125 ttl=54 id=32523 iplen=28
RCVD (1.1570s) ICMP 178.79.165.17 > 10.1.20.128 Port unreachable (type=3/code=3) ttl=49 id=16619 iplen=56
[...]
SENT (5.1020s) UDP 10.1.20.128:53 > 178.79.165.17:40125 ttl=64 id=32523 iplen=28
CAPT (5.1335s) UDP 80.38.10.21:45657 > 178.79.165.17:40125 ttl=54 id=32523 iplen=28
RCVD (5.1600s) ICMP 178.79.165.17 > 10.1.20.128 Port unreachable (type=3/code=3) ttl=49 id=16623 iplen=56

The output clearly shows the presence of a NAT device in the client's
local network. Note how the captured packet (CAPT) differs from the
SENT packet: the source address for the original packets is in the
reserved 10.0.0.0/8 range, while the address seen by the server is
80.38.10.21, the Internet side address of the NAT device. The source
port was also modified by the device. The line starting with RCVD
corresponds to the responses generated by the TCP/IP stack of the
machine where the Echo server is run.

Example 3. Discovering a transparent proxy

# nping --echo-client "public" echo.nmap.org --tcp -p80

Starting Nping ( https://nmap.org/nping )
SENT (1.2160s) TCP 10.0.1.77:41659 > 178.79.165.17:80 S ttl=64 id=3317 iplen=40 seq=567704200 win=1480
RCVD (1.2180s) TCP 178.79.165.17:80 > 10.0.1.77:41659 SA ttl=128 id=13177 iplen=44 seq=3647106954 win=16384 <mss 1460>
SENT (2.2150s) TCP 10.0.1.77:41659 > 178.79.165.17:80 S ttl=64 id=3317 iplen=40 seq=567704200 win=1480
SENT (3.2180s) TCP 10.0.1.77:41659 > 178.79.165.17:80 S ttl=64 id=3317 iplen=40 seq=567704200 win=1480
SENT (4.2190s) TCP 10.0.1.77:41659 > 178.79.165.17:80 S ttl=64 id=3317 iplen=40 seq=567704200 win=1480
SENT (5.2200s) TCP 10.0.1.77:41659 > 178.79.165.17:80 S ttl=64 id=3317 iplen=40 seq=567704200 win=1480

In this example, the output is a bit more tricky. The absence of error
messages shows that the Echo client has successfully established an
Echo session with the server. However, no CAPT packets can be seen in
the output. This means that none of the transmitted packets reached the
server. Interestingly, a TCP SYN-ACK packet was received in response to
the first TCP-SYN packet (and also, it is known that the target host
does not have port 80 open). This behavior reveals the presence of a
transparent web proxy cache server (which in this case is an old MS ISA
server).

TIMING AND PERFORMANCE OPTIONS
--delay time (Delay between probes)
This option lets you control for how long will Nping wait before
sending the next probe. Like in many other ping tools, the default
delay is one second. time must be a positive integer or floating
point number. By default it is specified in seconds, however you
can give an explicit unit by appending ms for milliseconds, s for
seconds, m for minutes, or h for hours (e.g. 2.5s, 45m, 2h).

--rate rate (Send probes at a given rate)
This option specifies the number of probes that Nping should send
per second. This option and --delay are inverses; --rate 20 is the
same as --delay 0.05. If both options are used, only the last one
in the parameter list counts.

MISCELLANEOUS OPTIONS
-h, --help (Display help)
Displays help information and exits.

-V, --version (Display version)
Displays the program's version number and quits.

-c rounds, --count rounds (Stop after a given number of rounds)
This option lets you specify the number of times that Nping should
loop over target hosts (and in some cases target ports). Nping
calls these "rounds". In a basic execution with only one target
(and only one target port in TCP/UDP modes), the number of rounds
matches the number of probes sent to the target host. However, in
more complex executions where Nping is run against multiple targets
and multiple ports, the number of rounds is the number of times
that Nping sends a complete set of probes that covers all target
IPs and all target ports. For example, if Nping is asked to send
TCP SYN packets to hosts 192.168.1.0-255 and ports 80 and 433, then
256 x 2 = 512 packets are sent in one round. So if you specify -c
100, Nping will loop over the different target hosts and ports 100
times, sending a total of 256 x 2 x 100 = 51200 packets. By default
Nping runs for 5 rounds. If a value of 0 is specified, Nping will
run continuously.

-e name, --interface name (Set the network interface to be used)
This option tells Nping what interface should be used to send and
receive packets. Nping should be able to detect this automatically,
but it will tell you if it cannot. name must be the name of an
existing network interface with an assigned IP address.

--privileged (Assume that the user is fully privileged)
Tells Nping to simply assume that it is privileged enough to
perform raw socket sends, packet sniffing, and similar operations
that usually require special privileges. By default Nping quits if
such operations are requested by a user that has no root or
administrator privileges. This option may be useful on Linux, BSD
or similar systems that can be configured to allow unprivileged
users to perform raw-packet transmissions. The NPING_PRIVILEGED
environment variable may be set as an alternative to using
--privileged.

--unprivileged (Assume that the user lacks raw socket privileges)
This option is the opposite of --privileged. It tells Nping to
treat the user as lacking network raw socket and sniffing
privileges. This is useful for testing, debugging, or when the raw
network functionality of your operating system is somehow broken.
The NPING_UNPRIVILEGED environment variable may be set as an
alternative to using --unprivileged.

--send-eth (Use raw ethernet sending)
Asks Nping to send packets at the raw ethernet (data link) layer
rather than the higher IP (network) layer. By default, Nping
chooses the one which is generally best for the platform it is
running on. Raw sockets (IP layer) are generally most efficient for
Unix machines, while ethernet frames are required for Windows
operation since Microsoft disabled raw socket support. Nping still
uses raw IP packets despite this option when there is no other
choice (such as non-ethernet connections).

--send-ip (Send at raw IP level)
Asks Nping to send packets via raw IP sockets rather than sending
lower level ethernet frames. It is the complement to the --send-eth
option.

--bpf-filter filter spec --filter filter spec (Set custom BPF filter)
This option lets you use a custom BPF filter. By default Nping
chooses a filter that is intended to capture most common responses
to the particular probes that are sent. For example, when sending
TCP packets, the filter is set to capture packets whose destination
port matches the probe's source port or ICMP error messages that
may be generated by the target or any intermediate device as a
result of the probe. If for some reason you expect strange packets
in response to sent probes or you just want to sniff a particular
kind of traffic, you can specify a custom filter using the BPF
syntax used by tools like tcpdump. See the documentation at
http://www.tcpdump.org/ for more information.

-H, --hide-sent (Do not display sent packets)
This option tells Nping not to print information about sent
packets. This can be useful when using very short inter-probe
delays (i.e., when flooding), because printing information to the
standard output has a computational cost and disabling it can
probably speed things up a bit. Also, it may be useful when using
Nping to detect active hosts or open ports (e.g. sending probes to
all TCP ports in a /24 subnet). In that case, users may not want to
see thousands of sent probes but just the replies generated by
active hosts.

-N, --no-capture (Do not attempt to capture replies)
This option tells Nping to skip packet capture. This means that
packets in response to sent probes will not be processed or
displayed. This can be useful when doing flooding and network stack
stress tests. Note that when this option is specified, most of the
statistics shown at the end of the execution will be useless. This
option does not work with TCP Connect mode.

OUTPUT OPTIONS
-v[level], --verbose [level] (Increase or set verbosity level)
Increases the verbosity level, causing Nping to print more
information during its execution. There are 9 levels of verbosity
(-4 to 4). Every instance of -v increments the verbosity level by
one (from its default value, level 0). Every instance of option -q
decrements the verbosity level by one. Alternatively you can
specify the level directly, as in -v3 or -v-1. These are the
available levels:

Level -4
No output at all. In some circumstances you may not want Nping
to produce any output (like when one of your work mates is
watching over your shoulder). In that case level -4 can be
useful because although you won't see any response packets,
probes will still be sent.

Level -3
Like level -4 but displays fatal error messages so you can
actually see if Nping is running or it failed due to some
error.

Level -2
Like level -3 but also displays warnings and recoverable
errors.

Level -1
Displays traditional run-time information (version, start time,
statistics, etc.) but does not display sent or received
packets.

Level 0
This is the default verbosity level. It behaves like level -1
but also displays sent and received packets and some other
important information.

Level 1
Like level 0 but it displays detailed information about timing,
flags, protocol details, etc.

Level 2
Like level 1 but displays very detailed information about sent
and received packets and other interesting information.

Level 3
Like level 2 but also displays the raw hexadecimal dump of sent
and received packets.

Level 4 and higher
Same as level 3.

-q[level], --reduce-verbosity [level] (Decrease verbosity level)
Decreases the verbosity level, causing Nping to print less
information during its execution.

-d[level] (Increase or set debugging level)
When even verbose mode doesn't provide sufficient data for you,
debugging is available to flood you with much more! As with the -v,
debugging is enabled with a command-line flag -d and the debug
level can be increased by specifying it multiple times. There are 7
debugging levels (0 to 6). Every instance of -d increments
debugging level by one. Provide an argument to -d to set the level
directly; for example -d4.

Debugging output is useful when you suspect a bug in Nping, or if
you are simply confused as to what Nping is doing and why. As this
feature is mostly intended for developers, debug lines aren't
always self-explanatory. You may get something like

NSOCK (1.0000s) Callback: TIMER SUCCESS for EID 12; tcpconnect_event_handler(): Received callback of type TIMER with status SUCCESS

If you don't understand a line, your only recourses are to ignore
it, look it up in the source code, or request help from the
development list (nmap-dev). Some lines are self-explanatory, but
the messages become more obscure as the debug level is increased.
These are the available levels:

Level 0
Level 0. No debug information at all. This is the default
level.

Level 1
In this level, only very important or high-level debug
information will be printed.

Level 2
Like level 1 but also displays important or medium-level debug
information

Level 3
Like level 2 but also displays regular and low-level debug
information.

Level 4
Like level 3 but also displays messages only a real Nping freak
would want to see.

Level 5
Like level 4 but it enables basic debug information related to
external libraries like Nsock.

Level 6
Like level 5 but it enables full, very detailed, debug
information related to external libraries like Nsock.

BUGS
Like its authors, Nping isn't perfect. But you can help make it better
by sending bug reports or even writing patches. If Nping doesn't behave
the way you expect, first upgrade to the latest version available from
https://nmap.org. If the problem persists, do some research to
determine whether it has already been discovered and addressed. Try
searching for the problem or error message on Google since that
aggregates so many forums. If nothing comes of this, create an Issue on
our tracker (http://issues.nmap.org) and/or mail a bug report to
<dev@nmap.org>. If you subscribe to the nmap-dev list before posting,
your message will bypass moderation and get through more quickly.
Subscribe at https://nmap.org/mailman/listinfo/dev. Please include
everything you have learned about the problem, as well as what version
of Nping you are using and what operating system version it is running
on. Other suggestions for improving Nping may be sent to the Nmap dev
mailing list as well.

If you are able to write a patch improving Nping or fixing a bug, that
is even better! Instructions for submitting patches or git pull
requests are available from
https://github.com/nmap/nmap/blob/master/CONTRIBUTING.md

Particularly sensitive issues such as a security reports may be sent
directly to Fyodor directly at <fyodor@nmap.org>. All other reports and
comments should use the dev list or issue tracker instead because more
people read, follow, and respond to those.

AUTHORS
Luis MartinGarcia <luis.mgarc@gmail.com> (http://www.luismg.com)

Fyodor <fyodor@nmap.org> (https://insecure.org)

NOTES
1. official type numbers assigned by IANA
http://www.iana.org/assignments/icmp-parameters

2. official numbers assigned by IANA
http://www.iana.org/assignments/arp-parameters/

3. official numbers listed by the IEEE
http://standards.ieee.org/regauth/ethertype/eth.txt

Nping 05/17/2023 NPING(1)