NAME

       dnstcpbench - tool to perform TCP benchmarking of nameservers

SYNOPSIS

       dnstcpbench [OPTION]... REMOTE-ADDRESS [REMOTE-PORT]

DESCRIPTION

       dnstcpbench  reads  DNS  queries  (by  default  from standard input) and sends them out in
       parallel to a remote nameserver. By default TCP/IP is used, but optionally, UDP  is  tried
       first, which allows for the benchmarking of TCP/IP fallback.

       The  program  reports  both mean and median numbers for queries per second and UDP and TCP
       latency. Each query only counts once, even if it is tried over UDP first. This effectively
       means that passing '-u' can lower query rates if many queries get shunted to TCP.

       The input format is one query per line: qname single-space qtype. An example:

          www.powerdns.com ANY

       When  benchmarking  extended  runs,  it may be necessary to enable TIME_WAIT recycling, as
       TCP/IP port tuples may otherwise run out. On Linux this is performed by running:

          echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle

       The equivalent for IPv6 is not known.

OPTIONS

       -f, <FILENAME>, --file <FILENAME>       FILENAME from which to read queries.  Defaults  to
       standard  input if unspecified.  -h, --help                              Provide a helpful
       message.  --timeout-msec <MSEC>                   MSEC milliseconds to wait for an answer.
       -u,  --udp-first                          Attempt resolution via UDP first, only do TCP if
       truncated answer is received.  -v, --verbose                           Be  wordy  on  what
       the  program  is  doing.   --workers <NUM>                         Use NUM parallel worker
       threads.

       REMOTE-ADDRESS: IPv4 or IPv6 to test against.

       REMOTE-PORT: Port to test against, defaults to 53.

BUGS

       Currently the timeout code does not actually perform non-blocking connects or writes. So a
       slow connect or slow writes will still cause low performance and delays.

       Median queries per second statistics are reported as 0 for sub-second runs.

AUTHOR

       PowerDNS.COM BV

COPYRIGHT

       PowerDNS.COM BV

                                           Sep 30, 2024                            DNSTCPBENCH(1)