Subject: Re: install/21999: localhost.domain not correctly set in /etc/hosts file
To: William Allen Simpson <>
From: Greg A. Woods <>
List: netbsd-bugs
Date: 06/27/2003 15:08:30
[ On Friday, June 27, 2003 at 08:37:44 (-0400), William Allen Simpson wrote: ]
> Subject: Re: install/21999: localhost.domain not correctly set in /etc/hosts file
> Alan Barrett wrote:
> > There's no need for a localhost.domain entry in /etc/hosts, nor for a
> > localhost.domain entry in any DNS zone files.  I haven't used anything
> > like that for years.
> > 
> > There is a need for a "localhost" entry in /etc/hosts, and NetBSD
> > installs a suitable entry by default.
> Yes.  Mentioned in the PR.  Although there is no trailing period on the 
> two A records.

/etc/hosts entries should not ever have trailing periods.  /etc/hosts
names do not have the full semantics of DNS host domain names.

> Maybe the fact that it came at the end of a sentence made the 
> description unclear?  NetBSD isn't trying to find "localhost.", it's 
> trying localhost.domain (such as,

What, exactly, in NetBSD is trying to find "localhost.$your_domain"?

> As previously mentioned, the "something that breaks" happens to be the 
> daily security update isn't delivered on a default install.

What, exactly, "breaks" in /etc/security?

> Certainly, based on RFC-1912, an argument could be made that some 
> domains would want to name a host "localhost.dom.ain", and the daily 
> security update will start being delivered to their root, instead of 
> its own.

That doesn't make any sense.

> Somehow, it gives me a more warm fuzzy feeling to know that some user 
> that really needs to talk to "localhost.dom.ain" on some other system 
> will have to remove a line from /etc/hosts.

That doesn't make any sense either.

> Now, is it easier and better to change the library code, as you suggest, 
> and regression test all applications?  

You haven't identified exactly what broke yet.

> Or, to add a 3 line change to sysinst, fixing one (currently duplicated) 
> line in the default /etc/hosts? 

As Alan says, nothing should be trying to resolve a host "localhost" in
any sub-domain in the first place, and anything that does is broken
(though of course such behaviour is not entirely unexpected given the
penchant of *BSD software to try to be helpful and qualify hostnames for

> Remember, /etc/hosts is local only, and (supposedly) not cached for 
> DNS response to other hosts. 

A nameserver should never look at /etc/hosts for any reason whatsoever.

								Greg A. Woods

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