The ABNF for SPF (http://www.openspf.org/RFC_4408#abnf) inlcudes:
ip6-network = <as per [RFC 3513], section 2.2>
; e.g., 2001:DB8::CD30
This is RFC 3513 section 2.2 (page break removed):
2.2 Text Representation of Addresses
There are three conventional forms for representing IPv6 addresses as
text strings:
1. The preferred form is x:x:x:x:x:x:x:x, where the 'x's are the
hexadecimal values of the eight 16-bit pieces of the address.
Examples:
FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
1080:0:0:0:8:800:200C:417A
Note that it is not necessary to write the leading zeros in an
individual field, but there must be at least one numeral in every
field (except for the case described in 2.).
2. Due to some methods of allocating certain styles of IPv6
addresses, it will be common for addresses to contain long strings
of zero bits. In order to make writing addresses containing zero
bits easier a special syntax is available to compress the zeros.
The use of "::" indicates one or more groups of 16 bits of zeros.
The "::" can only appear once in an address. The "::" can also be
used to compress leading or trailing zeros in an address.
For example, the following addresses:
1080:0:0:0:8:800:200C:417A a unicast address
FF01:0:0:0:0:0:0:101 a multicast address
0:0:0:0:0:0:0:1 the loopback address
0:0:0:0:0:0:0:0 the unspecified addresses
may be represented as:
1080::8:800:200C:417A a unicast address
FF01::101 a multicast address
::1 the loopback address
:: the unspecified addresses
Looking at this, it provides two forms for each address. I think that the SPF
RFC wants the long form (i.e. 1080:0:0:0:8:800:200C:417A) and not the short
form, but because the 3513 reference includes both styles and the ABNF
example is just an example (e.g.), the short form does not appear to be
excluded.
So, if I wanted an ip6 mechanism for the loopback address, it could be either:
ip6:0:0:0:0:0:0:0:1
or
ip6:::1
Is that what was intended? I'm guessing not and it's another erratum that's
fixed by changing "as per [RFC 3513], section 2.2" to "as per [RFC 3513],
section 2.2.1".
Comments?
Scott K
-------
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ip6-network = <as per [RFC 3513], section 2.2>
; e.g., 2001:DB8::CD30
This is RFC 3513 section 2.2 (page break removed):
2.2 Text Representation of Addresses
There are three conventional forms for representing IPv6 addresses as
text strings:
1. The preferred form is x:x:x:x:x:x:x:x, where the 'x's are the
hexadecimal values of the eight 16-bit pieces of the address.
Examples:
FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
1080:0:0:0:8:800:200C:417A
Note that it is not necessary to write the leading zeros in an
individual field, but there must be at least one numeral in every
field (except for the case described in 2.).
2. Due to some methods of allocating certain styles of IPv6
addresses, it will be common for addresses to contain long strings
of zero bits. In order to make writing addresses containing zero
bits easier a special syntax is available to compress the zeros.
The use of "::" indicates one or more groups of 16 bits of zeros.
The "::" can only appear once in an address. The "::" can also be
used to compress leading or trailing zeros in an address.
For example, the following addresses:
1080:0:0:0:8:800:200C:417A a unicast address
FF01:0:0:0:0:0:0:101 a multicast address
0:0:0:0:0:0:0:1 the loopback address
0:0:0:0:0:0:0:0 the unspecified addresses
may be represented as:
1080::8:800:200C:417A a unicast address
FF01::101 a multicast address
::1 the loopback address
:: the unspecified addresses
Looking at this, it provides two forms for each address. I think that the SPF
RFC wants the long form (i.e. 1080:0:0:0:8:800:200C:417A) and not the short
form, but because the 3513 reference includes both styles and the ABNF
example is just an example (e.g.), the short form does not appear to be
excluded.
So, if I wanted an ip6 mechanism for the loopback address, it could be either:
ip6:0:0:0:0:0:0:0:1
or
ip6:::1
Is that what was intended? I'm guessing not and it's another erratum that's
fixed by changing "as per [RFC 3513], section 2.2" to "as per [RFC 3513],
section 2.2.1".
Comments?
Scott K
-------
Sender Policy Framework: http://www.openspf.org/
Archives at http://archives.listbox.com/spf-discuss/current/
To unsubscribe, change your address, or temporarily deactivate your subscription,
please go to http://v2.listbox.com/member/?list_id=735