NAME

       kxdpgun - XDP-powered DNS benchmarking tool

SYNOPSIS

       kxdpgun [options] -i filename target_IP

DESCRIPTION

       Powerful generator of DNS traffic, sending and receiving packets through XDP.

       Queries  are  generated  according  to a textual file which is read sequentially in a loop
       until a configured duration elapses. The order of queries is not guaranteed. Responses are
       received (unless disabled) and counted, but not checked against queries.

       The  number  of  parallel  threads  is  autodetected  according  to  the  number of queues
       configured for the network interface.

   Parameters
       filename
              Path to the queries file. See the description below regarding the file format.

       target_IP
              The IPv4 or IPv6 address of remote destination.

   Options
       -t, --duration seconds
              Duration of traffic generation, specified as a decimal number in  seconds  (default
              is 5.0).

       -T, --tcp[=debug_mode]
              Send queries over TCP. See the list of optional debug modes below.

       -U, --quic[=debug_mode]
              Send queries over QUIC. See the list of optional debug modes below.

       -Q, --qps queries
              Number  of  queries-per-second  (approximately)  to be sent (default is 1000).  The
              program is not optimized for low speeds at which it may lose communication packets.
              The recommended minimum speed is 2 packets per thread (Rx/Tx queue).

       -b, --batch size
              Send  more queries in a batch. Improves QPS but may affect the counterpart's packet
              loss (default is 10 for UDP and 1 for TCP/QUIC).

       -r, --drop
              Drop incoming responses. Improves QPS, but disables response statistics.

       -p, --port number
              Remote destination port (default is 53 for UDP/TCP, 853 for QUIC).

       -F, --affinity cpu_spec
              CPU affinity for all threads specified in  the  format  [<cpu_start>][s<cpu_step>],
              where  <cpu_start>  is the CPU ID for the first thread and <cpu_step> is the CPU ID
              increment for next thread (default is 0s1).

       -i, --infile filename
              Path to a file with query templates.

       -I, --interface interface
              Network interface for outgoing communication. This can be useful in situations when
              the interfaces are in a bond for example.

       -l, --local localIP[/prefix]
              Override  the  auto-detected  source  IP  address. If an address range is specified
              instead, various IPs from the range will be used for  different  queries  uniformly
              (address range not supported in the QUIC mode).

       -L, --mac-local
              Override auto-detected local MAC address.

       -R, --mac-remote
              Override auto-detected remote MAC address.

       -v, --vlan id
              Add VLAN 802.1Q header with the given id. VLAN offloading should be disabled.

       -e, --edns-size size
              EDNS  UDP  payload  size,  range 512-4096 (default is 1232). Note that over XDP the
              maximum supported MTU is 1790.

       -m, --mode mode
              Set the XDP mode. Supported values are:

              • auto (default) – the XDP mode is  selected  automatically  to  achieve  the  best
                performance, which means that native driver support is preferred over the generic
                one, and zero-copy is used if available.

              • copy – the XDP socket copy mode is forced even if zero-copy  is  available.  This
                can resolve various driver issues, but at the cost of lower performance.

              • generic  – the generic XDP implementation is forced even if native implementation
                is available. This mode doesn't require support from the driver nor hardware, but
                offers the worst performance.

       -G, --qlog path
              Generate qlog files in the directory specified by path. The directory has to exist.

              This  option  is  ignored  if  not  in the QUIC mode. The recommended usage is with
              --quic=R or with low QPS. Otherwise, too many files are generated.

       -h, --help
              Print the program help.

       -V, --version
              Print the program version.

   Queries file format
       Each line describes a query in the form:

       query_name query_type [flags]

       Where query_name is a domain name to be queried, query_type is a  record  type  name,  and
       flags is a single character:

       E Send query with EDNS.

       D Request DNSSEC (EDNS + DO flag).

   TCP/QUIC debug modes
       0      Perform full handshake for all connections (QUIC only).

       1      Just send SYN (Initial) and receive SYN-ACK (Handshake).

       2      Perform  TCP/QUIC  handshake  and  don't  send  anything,  allow close initiated by
              counterpart.

       3      Perform TCP/QUIC handshake and don't react further.

       5      Send incomplete query (N-1 bytes) and don't react further.

       7      Send query and don't ACK the response or anything further.

       8      Don't close the connection and ignore close by counterpart.

       9      Operate normally except for not ACKing the final FIN+ACK (TCP only).

       R      Instead of opening a connection for each query, reuse connections.

   Signals
       Sending USR1 signal to a running process triggers current statistics dump to the  standard
       output.

NOTES

       Linux kernel 4.18+ is required.

       The  utility  has  to  be  executed  under  root  or with these capabilities: CAP_NET_RAW,
       CAP_NET_ADMIN, CAP_SYS_ADMIN, CAP_IPC_LOCK, and CAP_SYS_RESOURCE (Linux < 5.11).

       The utility allocates source UDP/TCP ports from the range 2000-65535.

EXIT VALUES

       Exit status of 0 means successful operation. Any other exit status indicates an error.

EXAMPLES

       Manually created queries file:

          abc6.example.com. AAAA
          nxdomain.example.com. A
          notzone. A
          a.example.com. NS E
          ab.example.com. A D
          abcd.example.com. DS D

       Queries file generated from a zone file (Knot DNS format):

          cat ZONE_FILE | awk "{print \$1,\$3}" | grep -E "(NS|DS|A|AAAA|PTR|MX|SOA)$" | sort -u -R > queries.txt

       Basic usage:

          # kxdpgun -i ~/queries.txt 2001:DB8::1

       Using UDP with increased batch size:

          # kxdpgun -t 20 -Q 1000000 -i ~/queries.txt -b 20 -p 8853 192.0.2.1

       Using TCP:

          # kxdpgun -t 20 -Q 100000 -i ~/queries.txt -T -p 8853 192.0.2.1

SEE ALSO

       kdig(1).

AUTHOR

       CZ.NIC Labs <https://www.knot-dns.cz>

COPYRIGHT

       Copyright 2010–2024, CZ.NIC, z.s.p.o.