On Thu, 6 Aug 1998, John Horne wrote:
> argus.plymouth.ac.uk => 141.163.2.1
> 141.163.2.1 => argus.plym.ac.uk
Yes, but argus.plym.ac.uk => 141.163.2.1
so checking IP => name => same IP would succeed. However, if somebody
has set up, say,
sender_host_accept = argus.plymouth.ac.uk
then doing the check by reverse lookup won't work. I need to invent a
strategy that will cover this sort of case, because I think it is
actually quite common. Maybe something like:
. Look up the IP address => yields argus.plym.ac.uk
. (Optionally) look up argus.plym.ac.uk and make sure it does give
back the same IP address. If not, behave as "host name unknown".
. When the name check shows that argus.plym.ac.uk != argus.plymouth.ac.uk,
observe that the name in the configuration list is a complete name (no
wild cards), so look up argus.plymouth.ac.uk and discover that the IPs
do in fact match, and so treat it as a match.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
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