SUMMARY: DNS and /etc/hosts

From: Terence P. Ma (tpm@Anat.UMSMed.Edu)
Date: Mon Jul 19 1993 - 16:53:24 CDT


I wrote last night ...

> Over the weekend I upgraded my Sun SS1+ from 4.1.1B to 4.1.3.
> Everything seemed to go well. I am running DNS without NIS. So, I
> recreated a libc.so.x.y.z file per the summary a few weeks ago. That
> fixed the problem of not being able to resolve the names of machines.
> However, for some reason, my system no longer recognizes or reads from
> the /etc/hosts file. I use it for a number of aliases for other
> machines that I log onto regularly.
>
> To try and solve this problem, I went in to the rc* files and commented
> out everything that calls up yp (NIS) and moved /var/yp to /var/yp.413.
> There is no /etc/yp. The machine happily figures out all the full names
> of machines, etc., but will not look into /etc/hosts. This appears to
> be a problem for my uucp connect to uunet where the alias is in
> /etc/hosts.
>
> It must be something simple, but I can't quite figure it out. Any
> suggestions? I'll summarize to the net, of course.

Well, it turns out that it is something relatively simple. Once DNS
is up, it doesn't call on /etc/hosts. I thought that this only
applied to NIS. I was wrong. As suggested by several, I should have
looked to the O'Reilly book on DNS, but I don't have a copy.

Fixes:

1) add CNAME records into the DNS data tables. This works
   beautifully.
2) install resolv+. This allows one to designate the order and
   location of resolving tables to look at. See proper
   implementation in the docs. (Current version: resolv+2.1;
   ftp from server.uga.edu; /pub/sun/resolv).

Regarding the uucp portion of my question. The Systems file (in HDB
uucp) wants a machine name (in my case, uunet). I found that if I
have uunet.uu.net in the Systems file, it doesn't work. However, if
I have a CNAME or entry into /etc/hosts (with resolv+ installed) it
works. So, I assume (perhaps incorrectly) that uucp looks to names
of machines defined somewhere in order to get to it.

Thanks to:

"Jim Davis" <jdavis@cs.arizona.edu>
Piete.Brooks@cl.cam.ac.uk
Andrew Watson <ajw@ansa.co.uk>
David Comay <dsc@seismo.CSS.GOV>
shankar@ulysses.att.com "Shankar Ishwar"
mccalld@Sonoma.EDU (CYBERMAN)
jkays@msc.edu (Jeff Kays)
John Valdes <valdes@geosun.uchicago.edu>
antonson@Software.ORG (Todd S. Antonson)
Barry Margolin <barmar@Think.COM>
strombrg@hydra.acs.uci.edu (Dan Stromberg)
Dwight Ernest <dwight@hyphen.com>

Regards!
Tere

--
Terence P. Ma, Ph.D.		Department of Anatomy
VOICE:	   601-984-1654		University of Mississippi Med. Ctr.
FAX:	   601-984-1655		2500 North State Street
INTERNET:  tpm@anat.UMSMED.EDU	Jackson, MS 39216-4505



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