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From "David Reid" <dr...@jetnet.co.uk>
Subject Re: IPv6 capability and name lookup cost
Date Fri, 06 Sep 2002 15:24:38 GMT
Looks fine to me.

What will the order of the returned matches be for All? IPv4 then IPv6 would
be my suggestion which we should be able to do with the changes you're
talking about I'd guess.

david

> Jeff Trawick <trawick@attglobal.net> writes:
>
> > A useful performance improvement can be achieved by allowing the
> > administrator to select the following algorithm:
> >
> >   lookup IPv4
> >   if at least one IPv4 address was found, we're done
> >   lookup IPv6
>
> Getting more specific, I envision a directive that works like this:
>
> NameLookups All|IPv4Okay|IPv6Okay
>
> All:      current behavior -- tell resolver to find everything
>
> IPv4Okay: try IPv4 first, don't look for IPv6 unless no IPv4 addresses
found
>           note: if the host is specified in the form of an IPv6
>           numeric address string, APR will do the right thing
> IPv6Okay: try IPv6 first, don't look for IPv4 unless no IPv6 addresses
found
>           note: if the host is specified in the form of an IPv4
>           numeric address string, APR will do the right thing
>
> (potentially we could add something like this in the future, though I
> don't think that is necessary now since it is an optimization for an
> error path:
>   IPv4Only: only look for IPv4 addresses
>   IPv6Only: only look for IPv6 addresses
> )
>
> I guess core should export the information via a function like
>
>   ap_get_name_lookup_opts(apr_int32_t *opts)
>
> which will set a variable to be OR-ed with any other appropriate
> apr_sockaddr_info_get() flags to achieve the proper behavior.
>
> --
> Jeff Trawick | trawick@attglobal.net
> Born in Roswell... married an alien...
>


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