John Keown wrote:
----- Original Message -----
From: "Paul Howarth" <paul(_at_)city-fan(_dot_)org>
Supposing there were DNS records:
smtp.example.com. A 192.168.1.1
mx.example.com. A 192.168.1.19
example.com. MX mx.example.com.
example.com. TXT "v=spf1 a:smtp.example.com/28 mx -all"
That would violate ip address notation and if spf accepts your example then
Which example, the one above, which is remarkably similar to the example given
in section 2.1 of the SPF spec at http://spf.pobox.com/spf-draft-200406.txt,
or the one using only ip4 mechanisms, which was similar to the one you were
originally complaining about?
spf NEEDS to be fixed before it one has to re-write all routing table and
routers on the internet.
If SPF supports a wider range of syntax that some routers, what is the
problem? Nobody is suggesting that all routers be upgraded to handle SPF-style
syntax. What have routers got to do with SPF?
What I am saying is xxx.yyy.zzz.1/24 does not conform to ip4 address space
Having poked around the RFCs using google, I'm unable to find a definitive
statement of what CIDR notation for IPv4 actually is (though I can for IPv6 -
RFC 2373 - but even that doesn't clearly say whether non-zero digits beyond
the prefix are forbidden or not).
and has no meaning. Now if we ant to change the rules then we need to do
that.
Yes it does. The bit after the slash is called the "prefix length". So you
take the leftmost prefix length bits and compare those and only those.
Anything beyond the prefix length is ignored. Simple.
Paul.