Provided by: kea-admin_2.6.3-1_amd64 
NAME
perfdhcp - DHCP benchmarking tool
SYNOPSIS
perfdhcp [-1] [-4 | -6] [-A encapsulation-level] [-b base] [-B] [-c] [-C separator] [-d drop-time] [-D
max-drop] [-e lease-type] [-E time-offset] [-f renew-rate] [-F release-rate] [-g thread-mode] [-h] [-i]
[-I ip-offset] [-J remote-address-list-file] [-l local-address|interface] [-L local-port] [-M
mac-list-file] [-n num-request] [-N remote-port] [-O random-offset] [-o code,hexstring] [--or
encapsulation-level:code,hexstring] [-p test-period] [-P preload] [-r rate] [-R num-clients] [-s seed]
[-S srvid-offset] [--scenario name] [-t report] [-T template-file] [-u] [-v] [-W exit-wait-time] [-w
script_name] [-x diagnostic-selector] [-X xid-offset] [server]
DESCRIPTION
perfdhcp is a DHCP benchmarking tool. It provides a way to measure the performance of DHCP servers by
generating large amounts of traffic from multiple simulated clients. It is able to test both IPv4 and
IPv6 servers, and provides statistics concerning response times and the number of requests that are
dropped.
The tool supports two different scenarios, which offer certain behaviors to be tested. By default (the
basic scenario), tests are run using the full four-packet exchange sequence (DORA for DHCPv4, SARR for
DHCPv6). An option is provided to run tests using the initial two-packet exchange (DO and SA) instead. It
is also possible to configure perfdhcp to send DHCPv6 RENEW and RELEASE messages at a specified rate, in
parallel with the DHCPv6 four-way exchanges. By default, if there is no response received with one
second, a response is considered lost and perfdhcp continues with other transactions.
A second scenario, called avalanche, is selected via --scenario avalanche. It first sends the number of
Discovery or Solicit messages specified by the -R option; then a retransmission (with an exponential
back-off mechanism) is used for each simulated client, until all requests are answered. It generates a
report when all clients receive their addresses, or when it is manually stopped. This scenario attempts
to replicate a case where the server is not able to handle the traffic swiftly enough. Real clients will
assume the packet or response was lost and will retransmit, further increasing DHCP traffic. This is
sometimes called an avalanche effect, thus the scenario name. Option -p is ignored in the avalanche
scenario.
When running a performance test, perfdhcp exchanges packets with the server under test as quickly as
possible, unless the -r parameter is used to limit the request rate. The length of the test can be
limited by setting a threshold on any or all of the number of requests made by perfdhcp, the elapsed
time, or the number of requests dropped by the server.
TEMPLATES
To allow the contents of packets sent to the server to be customized, perfdhcp allows the specification
of template files that determine the contents of the packets. For example, the customized packet may
contain a DHCPv6 ORO to request a set of options to be returned by the server, or it may contain the
Client FQDN option to request that the server perform DNS updates. This may be used to discover
performance bottlenecks for different server configurations (e.g. DDNS enabled or disabled).
Up to two template files can be specified on the command line, with each file representing the contents
of a particular type of packet, and the type being determined by the test being carried out. For example,
if testing DHCPv6:
• With no template files specified on the command line, perfdhcp generates both Solicit and Request
packets.
• With one template file specified, that file is used as the pattern for Solicit packets: perfdhcp
generates the Request packets.
• With two template files given on the command line, the first is used as the pattern for Solicit
packets, and the second as the pattern for Request packets.
(A similar determination applies to DHCPv4's DHCPDISCOVER and DHCPREQUEST packets.)
The template file holds the DHCP packet, represented as a stream of ASCII hexadecimal digits; it excludes
any IP/UDP stack headers. The template file must not contain any characters other than hexadecimal digits
and spaces. Spaces are discarded when the template file is parsed; in the file, 12B4 is the same as 12
B4, which is the same as 1 2 B 4.
The template files should be used in conjunction with the command-line parameters which specify offsets
of the data fields being modified in outbound packets. For example, the -E time-offset switch specifies
the offset of the DHCPv6 Elapsed Time option in the packet template. If the offset is specified,
perfdhcp injects the current elapsed-time value into this field before sending the packet to the server.
In many scenarios, perfdhcp needs to simulate multiple clients, each having a unique client identifier.
Since packets for each client are generated from the same template file, it is necessary to randomize the
client identifier (or HW address in DHCPv4) in the packet created from it. The -O random-offset option
allows specification of the offset in the template where randomization should be performed. It is
important to note that this offset points to the end (not the beginning) of the client identifier (or HW
address field). The number of bytes being randomized depends on the number of simulated clients. If the
number of simulated clients is between 1 and 255, only one byte (to which the randomization offset
points) is randomized. If the number of simulated clients is between 256 and 65535, two bytes are
randomized. Note that the last two bytes of the client identifier are randomized in this case: the byte
which the randomization offset parameter points to, and the one which precedes it (random-offset - 1). If
the number of simulated clients exceeds 65535, three bytes are randomized, and so on.
perfdhcp can simulate traffic from multiple subnets by enabling option -J and passing a path to a file
that contains v4 or v6 addresses to be used as relays in generated messages. That enables testing of vast
numbers of Kea shared networks. While testing DHCPv4, Kea should be started with the
KEA_TEST_SEND_RESPONSES_TO_SOURCE environment variable, to force Kea to send generated messages to the
source address of the incoming packet.
Templates may currently be used to generate packets being sent to the server in 4-way exchanges, i.e.
Solicit, Request (DHCPv6) and DHCPDISCOVER, DHCPREQUEST (DHCPv4). They cannot be used when Renew or
DHCPRELEASE packets are being sent.
OPTIONS
-1 Takes the server-id option from the first received message.
-4 Establishes DHCPv4 operation; this is the default. It is incompatible with the -6 option.
-6 Establishes DHCPv6 operation. It is incompatible with the -4 option.
-b basetype=value
Indicates the base MAC or DUID used to simulate different clients. The basetype may be "mac" or
"duid". (The keyword "ether" may alternatively used for MAC.) The -b option can be specified
multiple times. The MAC address must consist of six octets separated by single (:) or double (::)
colons; for example: mac=00:0c:01:02:03:04. The DUID value is a hexadecimal string; it must be at
least six octets long and not longer than 64 bytes, and the length must be less than 128
hexadecimal digits. For example: duid=0101010101010101010110111F14.
-d drop-time
Specifies the time after which a request is treated as having been lost. The value is given in
seconds and may contain a fractional component. The default is 1.
-e lease-type
Specifies the type of lease being requested from the server. It may be one of the following:
address-only
Only regular addresses (v4 or v6) are requested.
prefix-only
Only IPv6 prefixes are requested.
address-and-prefix
Both IPv6 addresses and prefixes are requested.
The -e prefix-only and -e address-and-prefix forms may not be used with the -4 option.
-F release-rate
Specifies the rate at which DHCPv4 DHCPRELEASE or DHCPv6 Release requests are sent to a server.
This value is only valid when used in conjunction with the exchange rate (given by -r rate).
Furthermore, the sum of this value and the renew-rate (given by -f rate) must be equal to or less
than the exchange rate value.
-f renew-rate
Specifies the rate at which DHCPv4 DHCPREQUEST or DHCPv6 Renew requests are sent to a server.
This value is only valid when used in conjunction with the exchange rate (given by -r rate).
Furthermore, the sum of this value and the release-rate (given by -F rate) must be equal to or
less than the exchange rate.
-g thread-mode
Allows selection of thread-mode, which can be either single or multi. In multi-thread mode,
packets are received in a separate thread, which allows better utilisation of CPUs. In a
single-CPU system it is better to run in one thread, to avoid threads blocking each other. If more
than one CPU is present in the system, multi-thread mode is the default; otherwise single-thread
is the default.
-h Prints help and exits.
-i Performs only the initial part of the exchange: DISCOVER-OFFER if -4 is selected,
Solicit-Advertise if -6 is chosen.
-i is incompatible with the following options: -1, -d, -D, -E, -S, -I and -F. In addition, it
cannot be used with multiple instances of -O, -T, and -X.
-J remote-address-list-file
Specifies a text file that includes multiple addresses, and is designed to test shared networks.
If provided, perfdhcp randomly chooses one of the addresses for each exchange, to generate traffic
from multiple subnets. When testing DHCPv4, it should be started with the
KEA_TEST_SEND_RESPONSES_TO_SOURCE=ENABLE environment variable; otherwise, perfdhcp will not be
able to receive responses.
-l local-addr|interface
For DHCPv4 operation, specifies the local hostname/address to use when communicating with the
server. By default, the interface address through which traffic would normally be routed to the
server is used. For DHCPv6 operation, specifies the name of the network interface through which
exchanges are initiated.
-L local-port
Specifies the local port to use. This must be zero or a positive integer up to 65535. A value of 0
(the default) allows perfdhcp to choose its own port.
-M mac-list-file
Specifies a text file containing a list of MAC addresses, one per line. If provided, a MAC address
is chosen randomly from this list for every new exchange. In DHCPv6, MAC addresses are used to
generate DUID-LLs. This parameter must not be used in conjunction with the -b parameter.
-N remote-port
Specifies the remote port to use. This must be zero or a positive integer up to 65535. A value of
0 (the default) allows perfdhcp to choose the standard service port.
-o code,hexstring
Forces perfdhcp to insert the specified extra option (or options if used multiple times) into
packets being transmitted. The code specifies the option code, and the hexstring is a hexadecimal
string that defines the content of the option. Care should be taken, as perfdhcp does not offer
any kind of logic behind the options; they are simply inserted into packets and sent as is. Be
careful not to duplicate options that are already inserted. For example, to insert the
client-class identifier (option code 60) with the string "docsis", use -o 60,646f63736973. The -o
may be used multiple times. The protocol family (-4 or -6) must be specified before using -o.
-P preload
Initiates preload exchanges back-to-back at startup. Must be 0 (the default) or a positive
integer.
-r rate
Initiates the rate of DORA/SARR (or if -i is given, DO/SA) exchanges per second. A periodic report
is generated showing the number of exchanges which were not completed, as well as the average
response latency. The program continues until interrupted, at which point a final report is
generated.
-R num-clients
Specifies how many different clients are used. With a value of 1 (the default), all requests
appear to come from the same client. Must be a positive number.
-s seed
Specifies the seed for randomization, making runs of perfdhcp repeatable. This must be 0 or a
positive integer. The value 0 means that a seed is not used; this is the default.
--scenario name
Specifies the type of scenario, and can be basic (the default) or avalanche.
-T template-file
Specifies a file containing the template to use as a stream of hexadecimal digits. This may be
specified up to two times and controls the contents of the packets sent (see the "Templates"
section above).
-u Enables checks for address uniqueness. The lease valid-lifetime should not be shorter than the
test duration, and clients should not request an address more than once without releasing it.
-v Displays the Kea version.
-V Displays the extended Kea version.
-W exit-wait-time
Specifies the exit-wait-time parameter, which causes perfdhcp to wait for a certain amount of time
after an exit condition has been met, to receive all packets without sending any new packets.
Expressed in microseconds. If not specified, 0 is used (i.e. exit immediately after exit
conditions are met).
-w script_name
Specifies the name of the script to be run before/after perfdhcp. When called, the script is
passed a single parameter, either "start" or "stop", indicating whether it is being called before
or after perfdhcp.
-x diagnostic-selector
Includes extended diagnostics in the output. This is a string of single keywords specifying the
operations for which verbose output is desired. The selector key letters are:
a Prints the decoded command-line arguments.
e Prints the exit reason.
i Prints the rate-processing details.
l Prints the received leases.
s Prints the first server ID.
t When finished, prints timers of all successful exchanges.
T When finished, prints templates.
-Y seconds
Time in seconds after which perfdhcp starts simulating the client waiting longer for server
responses. This increases the secs field in DHCPv4 and sends increased values in the Elapsed Time
option in DHCPv6. Must be used with -y.
-y seconds
Time in seconds during which perfdhcp simulates the client waiting longer for server responses.
This increases the secs field in DHCPv4 and sends increased values in the Elapsed Time option in
DHCPv6. Must be used with -Y.
DHCPV4-ONLY OPTIONS
The following options only apply for DHCPv4 (i.e. when -4 is given).
-B Forces broadcast handling.
DHCPV6-ONLY OPTIONS
The following options only apply for DHCPv6 (i.e. when -6 is given).
-c Adds a rapid-commit option (exchanges are Solicit-Advertise).
-A encapsulation-level
Specifies that relayed traffic must be generated. The argument specifies the level of
encapsulation, i.e. how many relay agents are simulated. Currently the only supported
encapsulation-level value is 1, which means that the generated traffic is equivalent to the amount
of traffic passing through a single relay agent.
--or encapsulation-level:code,hexstring
Forces perfdhcp to insert the specified extra option (or options if used multiple times) into a
relayed DHCPv6 message at the given level of encapsulation; currently, the only supported
encapsulation-level value is 1. This option is very similar to -o: the code specifies the option
code, and the hexstring is a hexadecimal string that defines the content of the option. Care
should be taken, as perfdhcp does not offer any kind of logic behind the options; they are simply
inserted into packets and sent as is. encapsulation-level: is optional; if it is omitted, the
default encapsulation-level value 1 is used. For example, to insert the Subscriber identifier
(option code 38) with a value 1234 at the first level of encapsulation, use --or 38,31323334 or
--or 1:38,31323334. The --or may be used multiple times, and it must be used in conjunction with
-A.
TEMPLATE-RELATED OPTIONS
The following options may only be used in conjunction with -T and control how perfdhcp modifies the
template. The options may be specified multiple times on the command line; each occurrence affects the
corresponding template file (see "Templates" above).
-E time-offset
Specifies the offset of the secs field (DHCPv4) or Elapsed Time option (DHCPv6) in the second
(i.e. Request) template; must be 0 or a positive integer. A value of 0 disables this.
-I ip-offset
Specifies the offset of the IP address (DHCPv4) in the requested-ip option or IA_NA option
(DHCPv6) in the second (Request) template.
-O random-offset
Specifies the offset of the last octet to randomize in the template. This must be an integer
greater than 3. The -T switch must be given to use this option.
-S srvid-offset
Specifies the offset of the server-id option in the second (Request) template. This must be a
positive integer, and the switch can only be used when the template option (-T) is also given.
-X xid-offset
Specifies the offset of the transaction ID (xid) in the template. This must be a positive integer,
and the switch can only be used when the template option (-T) is also given.
OPTIONS CONTROLLING A TEST
-D max-drop
Aborts the test immediately if "max-drop" requests have been dropped. Use -D 1 to abort if even a
single request has been dropped. "max-drop" must be a positive integer. If "max-drop" includes the
suffix %, it specifies the maximum percentage of requests that may be dropped before aborting. In
this case, testing of the threshold begins after 10 requests are expected to have been received.
-n num-requests
Initiates "num-request" transactions. No report is generated until all transactions have been
initiated/waited-for, after which a report is generated and the program terminates.
-p test-period
Sends requests for "test-period", which is specified in the same manner as -d. This can be used as
an alternative to -n, or both options can be given, in which case the testing is completed when
either limit is reached.
-t interval
Sets the delay (in seconds) between two successive reports.
-C separator
Suppresses the preliminary output and causes the interim data to only contain the values delimited
by separator. Used in conjunction with -t to produce easily parsable reports at -t intervals.
ARGUMENTS
server Indicates the server to test, specified as an IP address. In the DHCPv6 case, the special name all
can be used to refer to All_DHCP_Relay_Agents_and_Servers (the multicast address FF02::1:2), or
the special name servers to refer to All_DHCP_Servers (the multicast address FF05::1:3). The
server is mandatory except where the -l option is given to specify an interface, in which case it
defaults to all.
ERRORS
perfdhcp can report the following errors in the packet exchange:
tooshort
A message was received that was too short.
orphans
A message was received which does not match one sent to the server (i.e. it is a duplicate
message, a message that has arrived after an excessive delay, or one that is just not recognized).
locallimit
Local system limits have been reached when sending a message.
EXIT STATUS
perfdhcp exits with one of the following status codes:
0 Success.
1 General error.
2 Error in command-line arguments.
3 No general failures in operation, but one or more exchanges were unsuccessful.
USAGE EXAMPLES
Here is an example that simulates regular DHCPv4 traffic of 100 DHCPv4 devices (-R 100), 10 packets per
second (-r 10), shows the query/response rate details (-xi), shows a report every 2 seconds (-t 2), and
sends the packets to the IP 192.0.2.1:
sudo perfdhcp -xi -t 2 -r 10 -R 100 192.0.2.1
Here's a similar case, but for DHCPv6. Note that the DHCPv6 protocol uses link-local addresses, so the
interface (eth0 in this example) must be specified on which to send the traffic. all is a convenience
alias for All_DHCP_Relay_Agents_and_Servers (the multicast address FF02::1:2). It is also possible to use
the servers alias to refer to All_DHCP_Servers (the multicast address FF05::1:3). The default is all.
sudo perfdhcp -6 -xi -t 1 -r 1 -R 10 -l eth0 all
The following examples simulate normal DHCPv4 and DHCPv6 traffic that, after 3 seconds, starts pretending
not to receive any responses from the server for 10 seconds. The DHCPv4 protocol signals this by an
increased secs field, while DHCPv6 uses the Elapsed Time option. In real networks, this indicates that
clients are not getting responses in a timely matter. This can be used to simulate some HA scenarios, as
Kea uses the secs field and Elapsed Time option value as one of the indicators that the HA partner is not
responding. When enabled with -y and -Y, the secs and Elapsed Time values increase steadily.
sudo perfdhcp -xi -t 1 -r 1 -y 10 -Y 3 192.0.2.1
sudo perfdhcp -6 -xi -t 1 -r 1 -y 10 -Y 3 2001:db8::1
DOCUMENTATION
Kea comes with an extensive Kea Administrator Reference Manual that covers all aspects of running the Kea
software - compilation, installation, configuration, configuration examples, and much more. Kea also
features a Kea Messages Manual, which lists all possible messages Kea can print with a brief description
for each of them. Both documents are available in various formats (.txt, .html, .pdf) with the Kea
distribution. The Kea documentation is available at https://kea.readthedocs.io.
Kea source code is documented in the Kea Developer's Guide, available at ‐
https://reports.kea.isc.org/dev_guide/.
The Kea project website is available at https://kea.isc.org.
MAILING LISTS AND SUPPORT
There are two public mailing lists available for the Kea project. kea-users (kea-users at lists.isc.org)
is intended for Kea users, while kea-dev (kea-dev at lists.isc.org) is intended for Kea developers,
prospective contributors, and other advanced users. Both lists are available at https://lists.isc.org.
The community provides best-effort support on both of those lists.
ISC provides professional support for Kea services. See https://www.isc.org/kea/ for details.
HISTORY
The perfdhcp tool was initially coded in October 2011 by John DuBois, Francis Dupont, and Marcin
Siodelski of ISC. Kea 1.0.0, which included perfdhcp, was released in December 2015.
SEE ALSO
kea-dhcp4(8), kea-dhcp6(8), kea-dhcp-ddns(8), kea-ctrl-agent(8), kea-admin(8), kea-netconf(8),
keactrl(8), kea-lfc(8), Kea Administrator Reference Manual.
AUTHOR
Internet Systems Consortium
COPYRIGHT
2019-2024, Internet Systems Consortium
2.6.3 Jun 02, 2025 PERFDHCP(8)