NSPING(8) BSD System Manager's Manual NSPING(8)NAMEnsping — measure reachability and latency of DNS nameservers
SYNOPSISnsping [-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 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
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 host‐
name.
-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.
EXAMPLESnsping 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.
4.4BSD April 29, 2024 4.4BSD
