On Sun, 26 Oct 2003, Meng Weng Wong wrote:
thanks for the input. this is the new version.
is there an RFC that describes CIDR notation? i'd like to be able to
just say "see rfcXXXX for details".
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3.7 IP4
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Valid syntax:
- ip4:192.0.2.0/24
- ip4:192.0.2.1
An IP4 range is specified using network/prefix-length notation. The
network part is a dotted quad. The prefix-length is a number between
0 and 32 inclusive. If no prefix-length is given, /32 is assumed.
If the network-part contains non-zero bits beyond the specified
prefix, this is a mild syntax error which SPF clients MUST tolerate
by ignoring the non-zero bits.
Once apon a time, one of the junior sysadmins at the place i was working
added w.x.y.z/1 to the "relaying allowed subnets" setting of our main mta
(he didn't understand cidr notation, and thought /1 meant 'one host')
Our MTA allowed this, and we where an open relay for 1/2 the net (we caught
it in about 20mins later when his work was reviewed).
Given this operational expirence, I vote for 'bits set in the host portion
of a prefix' to be a syntax error, and ignored.
If the connecting IPv4 client IP lies in the specified network, this
mechanism matches.
--
[http://pointless.net/] [0x2ECA0975]
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