Re: [exim] Using CSA in reverse DNS zone

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Lähettäjä: Tony Finch
Päiväys:  
Vastaanottaja: John Horne
Kopio: Exim users
Aihe: Re: [exim] Using CSA in reverse DNS zone
On Thu, 7 Jun 2007, John Horne wrote:
>
> We are using CSA via SRV DNS records in our forward zones, but it seems
> the reverse entry we have is not right.


It looks to me like it is right from the CSA point of view, but BIND is
rather pedantic about SRV records. I'll point this out to the CSA authors
since it's probably worth fixing in the spec.

> The CSA doc I have says that the 'Target' ('@' in our case) is only used
> if the Weight is 2. Since the weight is 1 in this case, is it okay to
> replace our record with:
>
>   _client._smtp   IN   SRV 1 1 1  .    (<= note the dot)


Yes, that would be the appropriate fix.

The CSA spec disrecommends this use of null targets out of fear for
causing misdirected queries on the root nameservers, even though the
SRV spec requires that implementations handle null targets correctly.

Tony.
--
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\N}{([^N]*)(.)(.)(.*)}{\$1\$3\$2\$1\$3\n\$2\$3\$4\$3\n\$3\$2\$4}}