Re: On consistency and 192.0.0.0/24

[borg () uu3 net]

From what I looked at IANA Special Registry, this whole range looks
like some service IPs. I mean, they provide specific service within AS.
From me then, it looks like bogon. You should not receive routing for those
addresses from other AS. (PNI is out of scope here).


---------- Original message ----------

From: Tom Beecher <beecher () beecher cc>
To: "Jakob Heitz (jheitz)" <jheitz () cisco com>
Cc: "nanog () nanog org" <nanog () nanog org>
Subject: Re: On consistency and 192.0.0.0/24
Date: Tue, 14 May 2024 13:24:47 -0400

> That means that some IP addresses in the block 192.0.0.0/24 may be
> routable.
>
> So, I would not make this a bogon.

This ignores note 2 on the IANA definitions page, next to 192.0.0.0/24 :

> [2]
>
> Not useable unless by virtue of a more specific reservation.
>
>  Which then lists the more specific reservations, of which SOME are
forwardable , and some are not.

The categorization as 'bogon' or not would really be determined by
individual operator use cases, and where/how such a bogon filter is
applied.



On Tue, May 14, 2024 at 12:23˙˙PM Jakob Heitz (jheitz) via NANOG <
nanog () nanog org> wrote:

> RFC 5736 was obsoleted by RFC 6890.
>
> It says in part:
>
>
>
> 2.2.1.  Information Requirements
>
>
>
>    The IPv4 and IPv6 Special-Purpose Address Registries maintain the
>
>    following information regarding each entry:
>
> ˙˙
>
>    o  Forwardable - A boolean value indicating whether a router may
>
>       forward an IP datagram whose destination address is drawn from the
>
>       allocated special-purpose address block between external
>
>       interfaces.
>
> ˙˙
>
>
>
> That means that some IP addresses in the block 192.0.0.0/24 may be
> routable.
>
> So, I would not make this a bogon.
>
>
>
> A better way to filter IP routes is by policy, for example based upon
>
> IRR and RPKI records.
>
>
>
> Kind Regards,
>
> Jakob
>
>
>
> ---------- Original message ----------
>
> Date: Tue, 14 May 2024 12:00:15 +0200 (CEST)
> From: borg () uu3 net
>
>
> [10] 192.0.0.0/24 reserved for IANA IPv4 Special Purpose Address Registry
> [RFC5736]. Complete registration details for 192.0.0.0/24 are found in
> [IANA registry iana-ipv4-special-registry].
>
> Was RFC5736 obsoleted? I think not, so I would treat it as bogon.
>
> Its a nice tiny subnet for special purposes. I personaly use it
> as my Internal VM Net on my desktop for example.
>
>
> ---------- Original message ----------
>
> From: John Kristoff <jtk () dataplane org>
> To: NANOG <nanog () nanog org>
> Subject: On consistency and 192.0.0.0/24
> Date: Mon, 13 May 2024 16:18:47 -0500
>
> As one to never let a good academic question go unasked... what is it
> about 192.0.0.0/24 that is or isn't a bogon. This doesn't seem so
> straightforward an answer to me, at least in theory.  Although in
> practice it may already be decided whether one likes the answer or not.
>
> 192.0.0.0/24 was originally assigned to IANA for "protocol assignments"
> in IETF RFC 5736, and later added to the list of reserved / special use
> addresses in IETF RFC 6890 (aka BCP 153).   There is a corresponding
> IPv6 block (2001::/23), but it has a significantly different history.
>
> Team Cymru's bogon list includes the v4 prefix.  NLNOG's bogon
> filtering guide does not.  When I asked Job about NLNOG's position he
> said:
>
>   "I was unsure what this prefix??s future plans would be and erred on
>   the side of caution and didn??t include this prefix in the NLNOG bogon
>   list recommendations."
>
> The /24 as specified is not for "global" use, but some of the more
> specific assignments are or can be.  See:
> <
> https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
> > .
>
> From my cursory examination I can't find cases where the v4 prefix or
> more specifics have been publicly announced to any significant degree.
> This however is not the case for the IPv6 prefix (e.g., the AS112
> project, Teredo).
>
> Maybe you'd say the /24 should be filtered, but not the more specifics
> that are deemed available for global use.  That might be reasonable,
> except many reasonable people will filter small prefixes.
>
> IANA's language may have put any "do not filter" camp in a relatively
> weak position:
>
>   "Address prefixes listed in the Special-Purpose Address Registry are
>   not guaranteed routability in any particular local or global context."
>
> I can't remember hearing anyone complaining about bogon-related
> reachability problems with the aggregate IANA prefixes generally.  Is
> there a strong case to make that ops should not bogon filter any
> addresses in these prefixes?  At least with IPv4?  What about for IPv6?
>
> John