----- Original Message -----
From: "Robert Raszuk" <[email protected]>
Sent: Thursday, November 15, 2018 2:31 PM

> Hi Tom,
>
> I think no one "owns" address families across protocols.
>
> Those are per protocol specific entities and essentially even between
> protocols they have not much in common (except name which is likely a
bit
> of trigger for confusion here).

Robert,

Yeah, that is my impression.

But,

1 - we have an IANA-maintained register of them, which suggests
something that is agreed IETF-wide (or at least part thereof)

2-  RFC8349 "A YANG Data Model for Routing Management", which is
intended to be the basis for routing OAM, with YANG, says
"   o  The data model should be suitable for the common address
families"
as if there was a common understanding of what the term means.

So, triggers for confusing me.

Tom Petch

> Example:
>
> Take OSPFv3 AFs (on octet):
>
>
> +-------------+----------------------+--------------------+
>             | Value/Range | Designation          | Assignment Policy
|
>
+-------------+----------------------+--------------------+
>             | 0           | Base IPv6 Unicast AF | Already assigned
|
>             |             |                      |
|
>             | 1-31        | IPv6 Unicast AFs     | Already assigned
|
>             |             | dependent on local   |
|
>             |             | policy               |
|
>             |             |                      |
|
>             | 32          | Base IPv6 Multicast  | Already assigned
|
>             |             |                      |
|
>             | 33-63       | IPv6 Multicast AFs   | Already assigned
|
>             |             | dependent on local   |
|
>             |             | policy               |
|
>             |             |                      |
|
>             | 64          | Base IPv4 Unicast AF | Already assigned
|
>             |             |                      |
|
>             | 65-95       | IPv4 Unicast AFs     | Already assigned
|
>             |             | dependent on local   |
|
>             |             | policy               |
|
>             |             |                      |
|
>             | 96          | Base IPv4 Multicast  | Already assigned
|
>             |             |                      |
|
>             | 97-127      | IPv4 Multicast AFs   | Already assigned
|
>             |             | dependent on local   |
|
>             |             | policy               |
|
>             |             |                      |
|
>             | 128-255     | Unassigned           | Standards Action
|
>
+-------------+----------------------+--------------------+
>
> then take BGP AFs:  It reuses general notion of IETF AFs which is two
> octets.
>
> Number Description Reference Registration Date
> 0 Reserved
> 1 IP (IP version 4)
> 2 IP6 (IP version 6)
> 3 NSAP
> 4 HDLC (8-bit multidrop)
> 5 BBN 1822
> 6 802 (includes all 802 media plus Ethernet "canonical format")
> 7 E.163
> 8 E.164 (SMDS, Frame Relay, ATM)
> 9 F.69 (Telex)
> 10 X.121 (X.25, Frame Relay)
> 11 IPX
> 12 Appletalk
> 13 Decnet IV
> 14 Banyan Vines
> 15 E.164 with NSAP format subaddress [ATM Forum UNI 3.1. October
> 1995.][Andy_Malis]
> 16 DNS (Domain Name System)
> 17 Distinguished Name [Charles_Lynn]
> 18 AS Number [Charles_Lynn]
> 19 XTP over IP version 4 [Mike_Saul]
> 20 XTP over IP version 6 [Mike_Saul]
> 21 XTP native mode XTP [Mike_Saul]
> 22 Fibre Channel World-Wide Port Name [Mark_Bakke]
> 23 Fibre Channel World-Wide Node Name [Mark_Bakke]
> 24 GWID [Subra_Hegde]
> 25 AFI for L2VPN information [RFC4761][RFC6074]
> 26 MPLS-TP Section Endpoint Identifier [RFC7212]
> 27 MPLS-TP LSP Endpoint Identifier [RFC7212]
> 28 MPLS-TP Pseudowire Endpoint Identifier [RFC7212]
> 29 MT IP: Multi-Topology IP version 4 [RFC7307]
> 30 MT IPv6: Multi-Topology IP version 6 [RFC7307]
> 31-16383 Unassigned
> 16384 EIGRP Common Service Family [Donnie_Savage] 2008-05-13
> 16385 EIGRP IPv4 Service Family [Donnie_Savage] 2008-05-13
> 16386 EIGRP IPv6 Service Family [Donnie_Savage] 2008-05-13
> 16387 LISP Canonical Address Format (LCAF) [David_Meyer] 2009-11-12
> 16388 BGP-LS [RFC7752] 2013-03-20
> 16389 48-bit MAC [RFC7042] 2013-05-06
> 16390 64-bit MAC [RFC7042] 2013-05-06
> 16391 OUI [RFC7961] 2013-09-25
> 16392 MAC/24 [RFC7961] 2013-09-25
> 16393 MAC/40 [RFC7961] 2013-09-25
> 16394 IPv6/64 [RFC7961] 2013-09-25
> 16395 RBridge Port ID [RFC7961] 2013-09-25
> 16396 TRILL Nickname [RFC7455] 2014-09-02
> 16397-65534 Unassigned
> 65535 Reserved
>
>
> BGP during MP-BGP extension came with defintion of SAFIs and I guess
one
> can claim that BGP "owns" SAFI defintions (well for now :). But I
guess you
> are pointing out the lack of consistency for AFI definitions here
>
> To me it looks like the definition of ticket format for say IPv4
human.
> Across plane rides, train or busses you still see a ticket for the
same
> entity, but there is nothing in common across all of them :).
>
> Cheers,
> R.
>
> On Thu, Nov 15, 2018 at 2:03 PM tom petch <[email protected]> wrote:
>
> > Who owns address families?
> >
> > RFC8294 creates a YANG module for IANA to maintain which is tied
into
> > the IANA registry of Address Families giving a long list of Address
> > Families as enumeration.  This RFC definition is used by
> >  draft-ietf-isis-yang-isis-cfg
> >  draft-ietf-ospf-yang
> >  draft-ietf-pim-yang
> > So far so good.
> >
> > However, I think of AF as essentially BGP in origin and when I look
at
> > draft-ietf-idr-bgp-model
> > I see
> >      identity AFI_SAFI_TYPE {
> >        description "Base identity type for AFI,SAFI tuples for
BGP-4";
> >
> >      identity IPV4_UNICAST {
> >        base AFI_SAFI_TYPE;
> > etc.
> > I note that this uses identity, as opposed to enumeration, which is
the
> > preferred way of such things with YANG now and that it owes nothing
to
> > the IANA maintained registry of Address Families.
> >
> > This I-D has a common author with
> > draft-ietf-i2rs-rib-data-model
> > and again does not use the IANA definitions but instead
> >
> >    identity address-family {description  "Base identity from which
all
> > RIB
> >         address families are derived.";  }
> >
> >    identity ipv4-address-family {
> >      base "address-family"; description  "IPv4 RIB address
amily.";  }
> >
> >    identity ipv6-address-family
> >    { base "address-family"; description "IPv6 RIB address
family."; }
> >
> >    identity mpls-address-family {
> >      base "address-family"; description  "MPLS RIB address
family."; }
> > ...
> > a similar but different set of identities for address families.
> >
> > draft-ietf-l2sm-l2vpn-service-model-10
> > is similar but different
> >
> >   identity address-family {
> >     description "Identity for an address family.";   }
> >
> >   identity ipv4 {
> >     base address-family;
> >     description "Identity for IPv4 address family.";   }
> >
> >   identity ipv6 {     base address-family;
> >     description  "Identity for IPv6 address family.";   }
> >
> >   identity vpn-topology {
> >     description       "Base identity for VPN topology.";   }
> > ......
> >
> > Or again
> > draft-ietf-lisp-yang-10
> >
> >      identity lisp-address-family {
> >        description "Base identity from which identities describing
LISP
> >
> > address
> >           families are derived."; }
> >
> >      identity no-address-afi {
> >        base lisp-address-family;  description "IANA Reserved.";  }
> >
> >      identity ipv4-afi {
> >        base lisp-address-family; description "IANA IPv4 address
> > family.";      }
> >
> >      identity ipv4-prefix-afi {
> >        base lisp-address-family;
> >        description   "IANA IPv4 address family prefix.";      }
> >
> >      identity ipv6-afi {
> >        base lisp-address-family; description  "IANA IPv6 address
> > family.";      }
> > ...........
> >
> >
> > Meanwhile, RFC8349 " A YANG Data Model for Routing Management"
defines
> >      identity address-family {
> >        description   "Base identity from which identities describing
> > address
> >           families are derived."; }
> >
> > So far so good again, but it only adds
> >
> >      identity ipv4 { base address-family;
> >        description "This identity represents an IPv4 address
> > y.";      }
> >
> >      identity ipv6 {  base address-family;
> >        description "This identity represents an IPv6 address
> > amily.";  }
> >
> > and none of the other hundred or so.  The IANA Considerations of
this
> > RFC makes no mention of Address Families.
> >
> > This is of course all valid YANG and will coexist happily inside a
> > device but a user may not be so happy to have half a dozen or more
> > conflicting definitions of address family alongside an IANA registry
> > which is but little used.  Also, this is of course also a perfectly
> > valid way of working for the IETF, never do something once if you
can do
> > six different ways, but I am not sure that it improves The Internet!
> >
> > Tom Petch
> >
> > _______________________________________________
> > rtgwg mailing list
> > [email protected]
> > https://www.ietf.org/mailman/listinfo/rtgwg
> >
>

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