From: Henning Brauer (no email)
Date: Sat Dec 04 2004 - 09:54:51 EST
* Andre Oppermann <> [2004-12-03 11:04]:
> Mark Andrews wrote:
> >In article <> you write:
> >>You would put in a global wildcard that says no smtp sender here. Only
> >>for those boxes being legitimate SMTP to outside senders you'd put in a
> >>more specific record as shown above. You probably have to enter some
> >>dozen
> >>to one hundred servers this way. Sure your reverse zone scripts need some
> >>changes but it's only two or three lines.
> >>
> >>Ideally you could tell your DNS server in the zone file this:
> >>
> >>_send._smtp._srv.*.*.173.128.in-addr.arpa. IN TXT "0"
> >>_send._smtp._srv.*.*.82.198.in-addr.arpa. IN TXT "0"
> >>
> >>being overidden by more specific information on single IP addresses.
> >
> >
> > You obviouly do not know how wildcard work in the DNS or you
> > would not have made this suggestion. Please read RFC 1034
> > and work though Section 4.3.2. Algorithm with a QNAME of
> > _send._smtp._srv.1.1.173.128.in-addr.arpa.
>
> The wildcards are in the DNS server zone file for interpretation by the
> DNS server itself. It would not be published as such because that obviously
> wouldn't work as you prove. But nothing is preventing BIND or whatever
> from taking this wildcard record and answering every request with the
> wildcard "_send._smtp._srv.*" RR if no more-specific exists. This should
> be relatively straight forward to code. Wouldn't want to touch the code
> base of BIND but for DJBDNS I could somewhat easily implement it.
eh?
no need to...
Thus we propose expanding the reverse DNS tree with a subdomain with
the well known name
_srv
This subdomain MAY be inserted at any level in the DNS tree for IPv4
IN-ADDR.ARPA reverse zones. For IPv6, to limit the number of DNS
queries, _srv is only queried at the /128 (host), /64 (subnet) and /
32 (site) level. That way it can either provide information for a
specific IP address or for a whole network block. More specific
information takes precedence over information found closer to the top
of the tree.
-- Henning Brauer, BS Web Services, http://bsws.de - Unix is very simple, but it takes a genius to understand the simplicity. (Dennis Ritchie)
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