Hello,
This is my first post to slug - hopefully I've understood protocol from
reading the list for a month or so.
In the past, I've diagnosed dns client resolution issues using "options
debug" in resolv.conf or setting the RES_OPTIONS environment variable as
follows...
export RES_OPTIONS="debug"
r...@aixbox:/ <mailto:r...@toranim1:/> > ping smh.com.au <http://smh.com.au>
;; res_setoptions("debug", "env")..
;; debug
;; calling process id = 614598
;; res_nquerydomain(smh.com.au <http://smh.com.au>, <Nil>, 1, 1)
;; res_query(smh.com.au <http://smh.com.au>, 1, 1)
;; res_nmkquery(QUERY, smh.com.au <http://smh.com.au>, IN, A)
;; res_send()
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 467
;; flags: rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; smh.com.au <http://smh.com.au>, type = A, class = IN
;; Querying server (# 1) address = 10.201.4.8
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 467
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; smh.com.au <http://smh.com.au>, type = A, class = IN
smh.com.au <http://smh.com.au>. 1m12s IN A 203.26.51.71
PING smh.com.au <http://smh.com.au> (203.26.51.71): 56 data bytes
--- smh.com.au <http://smh.com.au> ping statistics ---
2 packets transmitted, 0 packets received, 100% packet loss
This has provided a means of tracing dns resolution issues, which has
proved to be valuable for me on many occasions - the environments have
been AIX, Solaris and Tru64
I use and manage two linux distros - Ubuntu 9.04 and sUSE 11.1. Both
these distros document the options debug in the man page for resolv.conf
However, neither Ubuntu or sUSE yield any dns client trace where I'd
expect them too.
b...@sam:~$ uname -a
Linux sam 2.6.28-17-generic #58-Ubuntu SMP Tue Dec 1 18:57:07 UTC 2009
i686 GNU/Linux
b...@sam:~$ export RES_OPTIONS="debug"
b...@sam:~$ ping www.smh.com.au
PING a1040.b.akamai.net (150.101.195.89) 56(84) bytes of data.
64 bytes from 150.101.195.89: icmp_seq=1 ttl=61 time=30.9 ms
Many moons ago, when I first read about options debug, I recall that
gethostbyname could be built with or without various RES_OPTIONS.
So, my questions are:
1) Is this the expected behaviour on various Linux distros or am I
missing something?
2) Can anyone advise how to enable the debug capabilities in gethostbyname?
Thanks in advance,
Ben Burke
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