On Mon, 12 May 1997, Philip Hazel wrote:
> They just set options in the resolver call
>
> qualify_single sets the RES_DEFNAMES option
> search_parents sets the RES_DNSRCH option
>
> The man page for the resolver that I've got says
>
> RES_DEFNAMES
> If set, res_search will append the default domain name to
> single-component names (those that do not contain a dot).
>
> RES_DNSRCH
> If this option is set, res_search will search for host names in the
> current domain and in parent domains.
>
> I have made a note to say explicitly in the Exim manual that it just
> sets those options and lets the resolver do its stuff.
My man page says pretty much the same...
RES_DEFNAMES Append the default domain name to single
label queries. This is the default.
RES_DNSRCH Search up the domain tree from the
default domain, in all but the top
level. This is the default.
The DNS stuff does what I want it to do so maybe I shouldn't worry. The
bit in the manual which confused me was the sentence: "[search_parents] is
different from the qualify_single option in that it applies to domains
containing dots." I read it as meaning that it only applied to domains
containing dots, but maybe that's just me. There is no need to respond to
this message, Philip. However I have copied it to the list in case there
are any DNS experts out there who might like to comment on the following
observations...
stoat is a host in the same domain as the host on which exim is running,
i.e. shef.ac.uk, so I would like user@stoat to resolve to
user@???. I also want user@cam to resolve to user@???.
If I set qualify_single to false neither of the addresses user@stoat and
user@cam succeeds. If I set qualify_single to true but search_parents to
false then user@cam fails, as I would expect. But...
1. Why should the success or failure of user@cam depend on whether or not
the local domain is appended to the single component, cam?
2. Why doesn't user@stoat get resolved to user@??? when
search_parents is true irrespective of the setting of qualify single?
Richard
--
Richard Gilbert
Corporate Information and Computing Services
University of Sheffield, Sheffield, S10 2TN, UK
Phone: +44 114 222 3028 Fax: +44 114 275 3899
