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

     nsping -- measure reachability and	latency	of DNS nameservers

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

     Nsping uses DNS queries to	monitor	reachability and operation of name-
     servers, 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 responsive-
     ness 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 host-
     name 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

     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 host-

     -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"

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

     -r	  (Redundant) use recursive queries.

     -R	  Don't	use recursive queries.

	    Ping the nameserver	""	until interrupted using	de-
	    faults (random queries, local domain name as zone, etc).

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

     nsping -h
	    Query repeatedly for "" from

     Thomas H. Ptacek, <>

     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. =)

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

4.4BSD				 May 13, 2021				4.4BSD


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