Include IPv6 zone IDs in 'IP' BNF?

[rohanmahy]

RFC6874 extends IP-literal URIs to support IPv6 zone IDs. the 'IP' app-string defines a bare address with an optional subnet mask (app-string-ip as IPaddress plus an optional slash and mask). IPaddress includes a regular IPv4 or IPv6 address but does not include IPv6 addresses with a zone ID:

fe80::bd0f:a8bc:6480:2389%en1

while there is no direct representation of a zone ID for a lower case 'ip', the IPv6 tagged array (tag 54) could be extended to include the zone ID with 'IP':

`54([128,h'fe80 0000 0000 0000 bd0f a8bc 6480 238b', "en1"])

If we don't want 'IP' to support zone IDs I think we should explicitly mention that in the draft.

[cabo]

RFC 9164 (tags 54 and 52) supports zone-IDs in the Interface format (section 3.1.3) only.
I'm not sure the 3986/6874 combo is good guidance for how Interface format IP addresses should be represented.

Section 2.2 already says:

   Note that there is no direct representation of an address combined
   with a prefix length; this can be represented as
   52([ip'192.0.2.42',24]), if needed.

In the tradition of messing up everything with zone identifiers, the CDDL for ip-zone-identifier in RFC 9164 is not consistent with the example in Section 3.2.

I'd rather stay out of the zone identifier quicksand until it settles.

[rohanmahy]

Hi, proposed a change to PR#63 that addresses my concern:

"If we don't want 'IP' to support zone IDs I think we should explicitly mention that in the draft."

[cabo]

(This was auto-closed as a result of merging #63 as a basis for an editorial attempt.)
As the discussion is not yet completed (#63 (comment)), this issue is reopened.

[cabo]

See also the thread under
Archived-At: https://mailarchive.ietf.org/arch/msg/cbor/oTnpnDt-Rl4K51L-OeLJ2LgEIDQ