> I am writing a program to recurively download web pages.  Right in the
> middle of running, name resolution stops working.  On three different
> machines in three different domains:
> 
> falcon.dol-esa.gov
> 
> cais3.cais.com
> 
> leidecker.gsfc.nasa.gov
> 
> If I run a script in the background that calls "nslookup
> www.netbsd.org" ever three minutes the name never goes away.
> Otherwise gethostbyname() spontaniously fails.

I have never, ever had problems similar to the ones that you describe,
on any host that i've tried to access any 'netbsd.org' hostname from.

i have to ask: are those hosts running caching nameservers?

if not:
	(1) if not, are they behind slow links, or
	(2) are the nameservers that they make requests to
	    particularly heavily loaded, or are they not caching
	    data for some reason?

It sounds like your local name server is doing something Very Wrong.

your local nameserver should do one lookup (i.e. from a NetBSD.ORG
primary or secondary name server) for one of the names in question,
then cache the results (if they're positive) for a period of time.
(right now, that "period of time" is "at least an hour.")

If you're seeing fluctuations with a period three minutes, or anything
under an hour or so, it can't easily be a "global" configuration
problem.

> As a test create a name in the same way that the other ones
> (www.netbsd.org, ftp.netbsd.org and sup.netbsd.org) have been done
> (i.e. alias mypc.someplace.remote to foo.netbsd.org) don't let anyone
> reference it for a while and see if you can resolve it via
> gethostbyname() inside of MIT, etc.

how long is 'a while'?




cgd