Re: [mif] [dnsext] [DNSOP] 2nd Last Call for MIF DNS server selection document

[Doug Barton <[e-mail]>]

On 10/21/2011 08:13, Keith Moore wrote:
> Names containing "." should not be subject to search lists.  Given a
> name like foo.bar, there's no reliable way to tell whether "bar" is a
> TLD or a subdomain of something in the search list. 

I've been following this discussion, mostly in the hopes that it would
go away. :)  However since the discussion keeps circling I thought I'd
throw in my 2 cents.

1. I think we're all in agreement that dot-terminated names (e.g.,
example.) should not be subject to search lists. I personally don't have
any problems with any document mentioning that this is the expected
behavior.

2. I think most of us agree that a bare label (no dots, e.g., example)
will almost certainly be subject to a search list. My suggestion would
be that the common behavior be described in a "here be dragons" format,
without attempting to be proscriptive.

3. For hostnames with a dot (although not necessarily ending in a TLD,
such as foo.example) I think it's reasonable to say that the desired
behavior is to first try to look them up "as is" without applying a
search list, and if that fails to then apply the search list; with the
same caveat as above, descriptive language for this document instead of
proscriptive.

In regards to 3, let's say I have a domain, example.org. In my network I
have various subdomains that represent various network segments, let's
say foo, bar, and baz. Personally, I find it convenient to put
'example.com' in the search list for all of my hosts, and then type 'ssh
host.bar' and go off on my merry way. Yes, I understand that in my
simple example I could theoretically put all 3 subdomains in the search
list. Now assume that my network isn't actually that simple ...


hth,

Doug

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