October 2007
Intermediate to advanced
1308 pages
161h 13m
English
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ResolverOptions
Tune DNS lookups All versions
The ResolverOptions
option allows you to tune the way DNS lookups are
performed. The forms of this option are as
follows:
O ResolverOptions=arg ... ← configuration file (V8.7 and later) -OResolverOptions="arg ..." ← command line (V8.7 and later) define(`confBIND_OPTS',`arg ...') ← mc configuration (V8.7 and later) -oI"arg ..." ← command line (V8.6 and later) OIarg ... ← configuration file (V8.6 and later) OIbool ← configuration file (deprecated) -oIbool ← command line (deprecated)
The arg is one or more
arguments that allow you to tune the behavior of the
name server. The arg
arguments are identical to the flags listed in
resolver(3), but you omit the
RES_ prefix.
For example, RES_DNSRCH is expressed as DNSRCH. A
flag can be preceded by a plus or minus sign to
enable or disable the corresponding name server
option. If no pluses or minuses appear, the name
server option is enabled just as though a plus were
present. Consider the following:
O ResolverOptions=+AAONLY -DNSRCH
These turn on the AAONLY name server option
(Authoritative Answers Only) and turn off the DNSRCH
name server option (search the domain path). If the
ResolverOptions
option is omitted entirely, the default is for the
DNSRCH, DEFNAMES, and RECURSE name server options to
be enabled and all others to be disabled. Thus, for
example, DNSRCH is always enabled unless you
specifically turn it off.
Beginning with V8.7 sendmail, the
special string HasWildcardMX can be listed along with ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.