Corrupt cache

[Mark_Andrews at isc.org]

> 
> > I was under the impression that the resolver algorithm would never append
> a single
> > label (e.g. "com") as a search element. That's what the whole "ndots"
> option was
> > created for, wasn't it? I.e. the ability to override the default minimum
> of 2
> > labels...
> 
> The default BIND 4.8.3 search list only "devolved" (to use Microsoft's
> term) to two labels, and the Windows resolvers follow that behavior,
> so that's right.  I suppose you could deliberately put a single-label
> domain name into the search list with the search directive, though.

	Note "domain a.b.c" produced different default search list to
	"domain a.b.c." (trailing period).

	domain dv.isc.org => dv.isc.org isc.org
	domain dv.isc.org. => dv.isc.org. isc.org. org.

	The following program will print the search list.

	Mark

#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <stdio.h>
main() {
        int i;
        res_init();
        for (i = 0; _res.dnsrch[i] != NULL && i < MAXDNSRCH; i++)
                fprintf(stdout,"%s\n", _res.dnsrch[i]);
}

> 
> ndots is different, though.  It's the number of dots that need to be
> present in a domain name argument to trigger the resolver to look up
> that argument as-is, before applying the search list.
> cricket
> 
> Men & Mice
> DNS Software & Services
> www.menandmice.com
> 
> Attend our next DNS and BIND class!  See
> http://www.menandmice.com/8000/8000_dns_training.html
> for the schedule and to register for upcoming classes
> 
> 
> 
--
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at isc.org