Hi Ben, You can debug most (all?) of the DNS client resolution issues with dig.
You can test all the DNS client features, from a simple query to a full transfer zone. Regards Rodolfo Martínez Dirección de Proyectos Aleux México | http://www.aleux.com On Tue, Jan 26, 2010 at 5:04 PM, Ben Burke <ben.bu...@internode.on.net> wrote: > 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 > -- > SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ > Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html > -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
