.TH dnstrace 1

.SH NAME
dnstrace \- dns lookup tool

.SH SYNOPSIS
.B dnstrace 
.I t
.I fqdn
.I r

.SH DESCRIPTION
.B dnstrace
searches for all DNS servers
that can affect the resolution of records of type  
.I t
under the domain name 
.IR fqdn ,
starting from the root server
.IR r .
You can list more than one root server.

.B dnstrace
uses the standard DNS resolution algorithm,
but follows all possible paths in the algorithm.
It prints all responses it receives from DNS servers;
it also prints warnings about slow servers, dead servers,
misdelegated (``lame'') servers, and misformatted packets.
.B dnstrace
is similar in spirit to DOC and dnswalk
but is much more effective than those tools at debugging resolution problems.

In versions 1.03 and above:
You can pipe
.B dnstrace
through
.BR dnstracesort (1)
for human-friendly output.
.B dnstrace
can take a long time to run,
so standard procedure is to save its output in a file:

  dnstrace any www.aol.com a.root-servers.net > AOL &

Then you can run
.BR dnstracesort (1)
to see the results so far:

  dnstracesort < AOL | less

The
.BR dnstracesort (1)
output uses
.I ul
codes
for boldface and underline;
these codes are displayed properly by
.BR less (1).

Beware that, as of January 2001,
.B dnstrace
produces more than 5 megabytes of output
for the complete trace of cr.yp.to
starting from all the root servers.
It ends up sending more than 6000 queries to more than 200 different servers.

.SH SEE ALSO
dnsip(1),
dnsipq(1),
dnsmx(1),
dnstxt(1),
dnsqr(1),
dnsq(1),
dnsname(1),
less(1),
tinydns-get(1)

http://cr.yp.to/djbdns.html