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NSPING(8)              DragonFly System Manager's Manual             NSPING(8)


NAME

     nsping - measure reachability and latency of DNS nameservers


SYNOPSIS

     nsping [-drR] [-c count] [-z zone] [-h hostname] [-t timer] [-p port]
            [-P port] [-a address] [-T type]
            [<address>]


DESCRIPTION

     Nsping uses DNS queries to monitor reachability and operation of
     nameservers, as well as the latency of DNS queries. It does this by
     sending random recursive DNS queries to the nameserver (avoiding the
     effects of DNS caching) and measuring the amount of time between the
     sending of the query and the receipt of the response packet.

     The latency of DNS transactions depends heavily on the data being queried
     for. The zone within which to query can be specified explicitly on the
     command line, or inferred from the local host. To measure the
     responsiveness of a nameserver for information it is authoritative for,
     specify one it's zones of authority as this zone.

     To measure basic network latency and DNS processing time, specify a
     hostname on the command line. If this is done, DNS queries sent by nsping
     will not be randomized, and nameservice caching will cause the program to
     measure only network+processing time. If latency between the first and
     subsequent queries does not vary greatly, nameservice caching may not be
     enabled on the probed server.

     Finally, a rough estimate of the latency between two sets of nameservers
     can be measured by querying one of those servers for information within a
     zone authoritative for the other servers. This would be more useful if
     there was a way to specify which of a zone's servers a target server
     queries.

     Nsping recognizes the following options:

     -c count
          Total number of DNS queries to send (default infinite).

     -z zone
          The DNS domain to formulate queries in.

     -h hostname
          Do not use random queries, but rather query repeatedly for one
          hostname.

     -t timespec
          Specify the interval timeout to send packets with, as an expression
          of seconds.subseconds (ie, 0.5 = half second).  (default 1 second).

     -p port
          The remote DNS server port.

     -P port
          The local port to send queries from

     -a address
          The local address from which to send queries.

     -T type
          The type of information to query for (default "a" for Internet "A"
          record).

     -d   Print debugging output (don't do this).

     -r   (Redundant) use recursive queries.

     -R   Don't use recursive queries.


EXAMPLES

     nsping ns.victim.com
            Ping the nameserver "ns.victim.com" until interrupted using
            defaults (random queries, local domain name as zone, etc).

     nsping -z internic.net -t .5 ns.victim.com
            As above, but query for names within the domain "internic.net",
            and do so every half-second instead of every second.

     nsping -h www.yahoo.com ns.victim.com
            Query repeatedly for "www.yahoo.com" from ns.victim.com.


AUTHOR

     Thomas H. Ptacek, <tqbf@secnet.com>


BUGS

     This is embryonic software. If you find a bug, let me know; I won't be
     surprised, but I will try to fix it for you. =)


HISTORY

     Real benchmarking tools can be found at WWW.CAIDA.ORG; this tool is
     merely inspired from them.

BSD 4.4                          October 1997                          BSD 4.4

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