RS6000 named

[Jack F. Vogel]

In article <121490.152613.heise1 at ibm.com> RAH at IBM.COM ("Russell A. Heise") writes:
 
> leclair at chamois.cs.uiowa.edu (Jeanne Leclair) writes:
 
> > I recently started bringing up a 530 RS6000 and want to run named.  I set up
> > named.boot, loopback.rev and root.cache like on our other machines running
> > named and fired it up. It works great for machines local to our departmental
> > domain (cs.uiowa.edu)... For on-campus hosts in other departments, however,
> > you would expect to be able to use hostname.dept-domain...that doesn't work 
 
> You missed nothing; yes, this is how it's supposed to work.  I assume you
> have set up an appropriate /etc/resolv.conf.  If so, AIX follows a two-step
> process to resolve a name to an address.  (1) First, AIX looks at the name
> passed *to* it.  If the name has a period (.) anywhere in it, AIX leaves it
> untouched.  Otherwise, AIX appends the domain string from /etc/resolv.conf.
> (2) Next, AIX sends the result of step 1 to the nameserver(s) listed in
> /etc/resolv.conf.
 
Sorry Russ, you are almost correct but not quite. Point 1 is not accurate,
at least not for the more recent revisions of BIND from Berkeley. I am not
sure what level code the 6000 has but as for AIX 1.2, it now has version 4.8.1
and this supports partially qualified names. What this means is that it is
not that a name has a period "anywhere" in it, but only a terminating period
that will leave it untouched. Otherwise it will append the domain and attempt
a lookup of that name.

For instance, locus.com has 3 subdomains currently, la, sd, and bos, and our
primary nameserver is in both locus.com and la.locus.com. What this means
is that if I query the fully unqualified 'host' it first attempts to lookup
'host.la.locus.com' and then 'host.locus.com'. Similarly, if i query
'host.sd' it will lookup 'host.sd.la.locus.com' which will fail, but then
'host.sd.locus.com' which will succeed.

Of course, there is an important caveat to be made here. This capability is
in the resolver (the application interface to the nameserver), but some
application or higher level interface may not support it, it depends on how
it interfaces to the resolver. For instance, until a recent fix I made
AIX 1.2's gethostbyname() was not making its queries correctly so that
this type partial lookup would fail. On current code, however, it works
correctly.

So lookups of the form 'host.subdomain' SHOULD work, assuming that your
local nameserver either is a primary for the whole uiowa domain, or has
access to such a server. I don't have access to a 6000 to check this out
but if it doesn't work then the version 3 folk need to follow 1.2 and
upgrade their version of BIND.

Disclaimer: I do not speak for LCC or IBM.

-- 
Jack F. Vogel			jackv at locus.com
AIX370 Technical Support	       - or -
Locus Computing Corp.		jackv at turnkey.TCC.COM