[exim] Using CSA in reverse DNS zone

Hi,

We are using CSA via SRV DNS records in our forward zones, but it seems
the reverse entry we have is not right. (Section 40.39 of the Exim
manual explains about CSA.)

At present we have:

_client._smtp IN SRV 1 1 1 @

but the BIND 9 named-checkzone program complains that this is invalid
because the '@' (163.141.in-addr.arpa in this case) has no A/AAAA
records - which it doesn't. 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)

named-checkzone doesn't complain with this.

My question is, is this okay or are there any possible problems in using
the root (.) as the target?


Thanks,

John.

-- 
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John Horne, University of Plymouth, UK  Tel: +44 (0)1752 233914
E-mail: John.Horne@???       Fax: +44 (0)1752 233839