Babel routing protocol B. Stark
Internet-Draft AT&T
Intended status: Informational October 22, 2018
Expires: April 25, 2019
Babel Information Model
draft-ietf-babel-information-model-04
Abstract
This Babel Information Model can be used to create data models under
various data modeling regimes (e.g., YANG). It allows a Babel
implementation (via a management protocol such as NETCONF) to report
on its current state and may allow some limited configuration of
protocol constants.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
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and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 25, 2019.
Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Notation . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. The Information Model . . . . . . . . . . . . . . . . . . . . 5
3.1. Definition of babel-information-obj . . . . . . . . . . . 5
3.2. Definition of babel-constants-obj . . . . . . . . . . . . 6
3.3. Definition of babel-interfaces-obj . . . . . . . . . . . 7
3.4. Definition of babel-neighbors-obj . . . . . . . . . . . . 8
3.5. Definition of babel-security-obj . . . . . . . . . . . . 10
3.6. Definition of babel-routes-obj . . . . . . . . . . . . . 11
4. Common Objects . . . . . . . . . . . . . . . . . . . . . . . 12
4.1. Definition of babel-credential-obj . . . . . . . . . . . 12
4.2. Definition of babel-log-obj . . . . . . . . . . . . . . . 13
5. Extending the Information Model . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . 15
Appendix A. Open Issues . . . . . . . . . . . . . . . . . . . . 17
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 19
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
Babel is a loop-avoiding distance-vector routing protocol defined in
[I-D.ietf-babel-rfc6126bis]. [I-D.ietf-babel-hmac] defines a
security mechanism that allows Babel messages to be cryptographically
authenticated, and [I-D.ietf-babel-dtls] defines a security mechanism
that allows Babel messages to be encrypted. This document describes
an information model for Babel (including implementations using one
of these security mechanisms) that can be used to create management
protocol data models (such as a NETCONF [RFC6241] YANG [RFC7950] data
model).
Due to the simplicity of the Babel protocol, most of the information
model is focused on reporting Babel protocol operational state, and
very little of that is considered mandatory to implement (contingent
on a management protocol with Babel support being implemented). Some
parameters may be configurable. However, it is up to the Babel
implementation whether to allow any of these to be configured within
its implementation. Where the implementation does not allow
configuration of these parameters, it may still choose to expose them
as read-only.
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The Information Model is presented using a hierarchical structure.
This does not preclude a data model based on this Information Model
from using a referential or other structure.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119] and updated
by [RFC8174].
1.2. Notation
This document uses a programming language-like notation to define the
properties of the objects of the information model. An optional
property is enclosed by square brackets, [ ], and a list property is
indicated by two numbers in angle brackets, <m..n>, where m indicates
the minimal number of list elements, and n indicates the maximum
number of list elements. The symbol * for n means there are no
defined limits on the number of list elements. Each parameter and
object includes an indication of "ro" or "rw". "ro" means the
parameter or object is read-only. "rw" means it is read-write. For
an object, read-write means instances of the object can be created or
deleted. If an implementation is allowed to choose to implement a
"rw" parameter as read-only, this is noted in the parameter
description.
The object definitions use base types that are defined as follows:
binary A binary string (sequence of octets).
boolean A type representing a boolean value.
counter A non-negative integer that monotonically increases.
Counters may have discontinuities and they are not
expected to persist across restarts.
credentials An opaque type representing credentials needed by a
cryptographic mechanism to secure communication. Data
models must expand this opaque type as needed and
required by the security protocols utilized.
datetime A type representing a date and time using the Gregorian
calendar. The datetime format MUST conform to RFC 3339
[RFC3339].
int A type representing signed or unsigned integer numbers.
This information model does not define a precision nor
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does it make a distinction between signed and unsigned
number ranges.
ip-address A type representing an IP address. This type supports
both IPv4 and IPv6 addresses.
string A type representing a human-readable string consisting of
a (possibly restricted) subset of Unicode and ISO/IEC
10646 [ISO.10646] characters.
uri A type representing a Uniform Resource Identifier as
defined in STD 66 [RFC3986].
2. Overview
The Information Model is hierarchically structured as follows:
information object
includes implementation version, router id, this node seqno,
enable flag parameters, supported security mechanisms
constants object (exactly one per information object)
includes UDP port and optional multicast group
parameters
interfaces object
includes interface reference, Hello seqno and intervals,
update interval, link type, metric computation parameters
neighbors object
includes neighbor IP address, Hello history, cost
parameters
security object (per interface)
includes enable flag, self credentials (credential
object), trusted credentials (credential object)
security object (common to all interfaces)
includes enable flag, self credentials (credential
object), trusted credentials (credential object)
routes object
includes route prefix, source router, reference to
advertising neighbor, metric, sequence number, whether
route is feasible, whether route is selected
Most parameters are read-only. Following is a list of the parameters
that are not required to be read-only:
o enable/disable Babel
o Constant: UDP port
o Constant: IPv6 multicast group
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o Interface: Link type
o Interface: External cost (must be configurable if implemented, but
implementation is optional)
o Interface: enable/disable Babel on this interface
o Interface: enable/disable message log
o Security: enable/disable this security mechanism
o Security: self credentials
o Security: trusted credentials
o Security: enable/disable security log
Note that this overview is intended simply to be informative and is
not normative. If there is any discrepancy between this overview and
the detailed information model definitions in subsequent sections,
the error is in this overview.
3. The Information Model
3.1. Definition of babel-information-obj
object {
string ro babel-implementation-version;
boolean rw babel-enable;
binary ro babel-self-router-id;
string ro babel-supported-link-types<1..*>;
[int ro babel-self-seqno;]
string ro babel-metric-comp-algorithms<1..*>;
string ro babel-security-supported<0..*>;
babel-constants-obj ro babel-constants;
babel-interfaces-obj ro babel-interfaces<0..*>;
babel-routes-obj ro babel-routes<0..*>;
babel-security-obj ro babel-security<0..*>;
} babel-information-obj;
babel-implementation-version: The name and version of this
implementation of the Babel protocol.
babel-enable: When written, it configures whether the protocol shoud
be enabled (true) or disabled (false). A read from the running or
intended datastore indicates the configured administrative value
of whether the protocol is enabled (true) or not (false). A read
from the operational datastore indicates whether the protocol is
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actually running (true) or not (i.e., it indicates the operational
state of the protocol). A data model that does not replicate
parameters for running and operational datastores can implement
this as two separate parameters. An implementation MAY choose to
expose this parameter as read-only ("ro").
babel-self-router-id: The router-id used by this instance of the
Babel protocol to identify itself. [I-D.ietf-babel-rfc6126bis]
describes this as an arbitrary string of 8 octets.
babel-supported-link-types: Lists the set of link types supported by
this instance of Babel. Valid enumeration values are defined in
the Babel Link Types registry (see Section 7).
babel-self-seqno: The current sequence number included in route
updates for routes originated by this node.
babel-metric-comp-algorithms: List of supported cost computation
algorithms. Possible values include "k-out-of-j", and "ETX".
babel-security-supported: List of supported security mechanisms. As
Babel security mechanisms are defined, they will need to indicate
what enumeration value is to be used to represent them in this
parameter.
babel-constants: A babel-constants-obj object.
babel-interfaces: A set of babel-interface-obj objects.
babel-security: A babel-security-obj object that applies to all
interfaces. If this object is implemented, it allows a security
mechanism to be enabled or disabled in a manner that applies to
all Babel messages on all interfaces.
babel-routes: A set of babel-route-obj objects. Contains the routes
known to this node.
3.2. Definition of babel-constants-obj
object {
int rw babel-udp-port;
[ip-address rw babel-mcast-group;]
} babel-constants-obj;
babel-udp-port: UDP port for sending and listening for Babel
messages. Default is 6696. An implementation MAY choose to
expose this parameter as read-only ("ro").
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babel-mcast-group: Multicast group for sending and listening to
multicast announcements on IPv6. Default is ff02:0:0:0:0:0:1:6.
An implementation MAY choose to expose this parameter as read-only
("ro").
3.3. Definition of babel-interfaces-obj
object {
string ro babel-interface-reference;
[boolean rw babel-interface-enable;]
int rw babel-link-type;
string ro babel-interface-metric-algorithm;
[int ro babel-mcast-hello-seqno;]
[int ro babel-mcast-hello-interval;]
[int ro babel-update-interval;]
[boolean rw babel-message-log-enable;]
[babel-log-obj ro babel-message-log<0..*>;]
babel-neighbors-obj ro babel-neighbors<0..*>;
[babel-security-obj ro babel-interface-security<0..*>;]
} babel-interfaces-obj;
babel-interface-reference: Reference to an interface object as
defined by the data model (e.g., YANG [RFC7950], BBF [TR-181]).
Data model is assumed to allow for referencing of interface
objects which may be at any layer (physical, Ethernet MAC, IP,
tunneled IP, etc.). referencing syntax will be specific to the
data model. If there is no set of interface objects available,
this should be a string that indicates the interface name used by
the underlying operating system.
babel-interface-enable: When written, it configures whether the
protocol should be enabled (true) or disabled (false) on this
interface. A read from the running or intended datastore
indicates the configured administrative value of whether the
protocol is enabled (true) or not (false). A read from the
operational datastore indicates whether the protocol is actually
running (true) or not (i.e., it indicates the operational state of
the protocol). A data model that does not replicate parameters
for running and operational datastores can implement this as two
separate parameters. An implementation MAY choose to expose this
parameter as read-only ("ro").
babel-link-type: Indicates the type of link. Valid enumeration
values are identified in Babel Link Types registry. An
implementation MAY choose to expose this parameter as read-only
("ro").
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babel-interface-metric-algorithm: Indicates the metric computation
algorithm used on this interface. The value MUST be one of those
listed in the babel-information-obj babel-metric-comp-algorithms
parameter.
babel-mcast-hello-seqno: The current sequence number in use for
multicast hellos sent on this interface.
babel-mcast-hello-interval: The current interval in use for
multicast hellos sent on this interface.
babel-update-interval: The current interval in use for all updates
(multicast and unicast) sent on this interface.
babel-message-log-enable: When written, it configures whether
logging should be enabled (true) or disabled (false). A read from
the running or intended datastore indicates the configured
administrative value of whether logging is enabled (true) or not
(false). A read from the operational datastore indicates whether
logging is actually running (true) or not (i.e., it indicates the
operational state). A data model that does not replicate
parameters for running and operational datastores can implement
this as two separate parameters. An implementation MAY choose to
expose this parameter as read-only ("ro").
babel-message-log: Log entries that have timestamp of a received
Babel message and the entire received Babel message (including
Ethernet frame and IP headers, if possible). An implementation
must restrict the size of this log, but how and what size is
implementation-specific. If this log is implemented, a mechanism
to clear it SHOULD be provided.
babel-neighbors: A set of babel-neighbors-obj objects.
babel-interface-security: A babel-security-obj object that applies
to this interface. If implemented, this allows security to be
enabled only on specific interfaces or allows different security
mechanisms to be enabled on different interfaces.
3.4. Definition of babel-neighbors-obj
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object {
ip-address ro babel-neighbor-address;
[binary ro babel-hello-mcast-history;]
[binary ro babel-hello-ucast-history;]
int ro babel-txcost;
int ro babel-exp-mcast-hello-seqno;
int ro babel-exp-ucast-hello-seqno;
[int ro babel-ucast-hello-seqno;]
[int ro babel-ucast-hello-interval;]
[int ro babel-rxcost]
[int ro babel-cost]
} babel-neighbors-obj;
babel-neighbor-address: IPv4 or IPv6 address the neighbor sends
messages from
babel-hello-mcast-history: The multicast Hello history of whether or
not the multicast Hello messages prior to babel-exp-mcast-hello-
seqno were received. A binary sequence where the most recently
received Hello is expressed as a "1" placed in the left-most bit,
with prior bits shifted right (and "0" bits placed between prior
Hello bits and most recent Hello for any not-received Hellos).
This value should be displayed using hex digits ([0-9a-fA-F]).
See [I-D.ietf-babel-rfc6126bis], section A.1.
babel-hello-ucast-history: The unicast Hello history of whether or
not the unicast Hello messages prior to babel-exp-ucast-hello-
seqno were received. A binary sequence where the most recently
received Hello is expressed as a "1" placed in the left-most bit,
with prior bits shifted right (and "0" bits placed between prior
Hello bits and most recent Hello for any not-received Hellos).
This value should be displayed using hex digits ([0-9a-fA-F]).
See [I-D.ietf-babel-rfc6126bis], section A.1.
babel-txcost: Transmission cost value from the last IHU packet
received from this neighbor, or maximum value (infinity) to
indicate the IHU hold timer for this neighbor has expired. See
[I-D.ietf-babel-rfc6126bis], section 3.4.2.
babel-exp-mcast-hello-seqno: Expected multicast Hello sequence
number of next Hello to be received from this neighbor. If
multicast Hello messages are not expected, or processing of
multicast messages is not enabled, this MUST be 0.
babel-exp-ucast-hello-seqno: Expected unicast Hello sequence number
of next Hello to be received from this neighbor. If unicast Hello
messages are not expected, or processing of unicast messages is
not enabled, this MUST be 0.
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babel-ucast-hello-seqno: The current sequence number in use for
unicast hellos sent to this neighbor.
babel-ucast-hello-interval: The current interval in use for unicast
hellos sent to this neighbor.
babel-rxcost: Reception cost calculated for this neighbor. This
value is usually derived from the Hello history, which may be
combined with other data, such as statistics maintained by the
link layer. The rxcost is sent to a neighbor in each IHU. See
[I-D.ietf-babel-rfc6126bis], section 3.4.3.
babel-cost: Link cost is computed from the values maintained in the
neighbor table: the statistics kept in the neighbor table about
the reception of Hellos, and the txcost computed from received IHU
packets.
3.5. Definition of babel-security-obj
object {
string ro babel-security-mechanism
boolean rw babel-security-enable;
babel-credential-obj ro babel-security-self-cred<0..*>;
babel-credential-obj ro babel-security-trust<0..*>;
[boolean rw babel-credvalid-log-enable;]
[babel-log-obj ro babel-credvalid-log<0..*>;]
} babel-security-obj;
babel-security-mechanism: The name of the security mechanism this
object instance is about. The value MUST be the same as one of
the enumerations listed in the babel-security-supported parameter.
babel-security-enable: When written, it configures whether this
security mechanism should be enabled (true) or disabled (false).
A read from the running or intended datastore indicates the
configured administrative value of whether this security mechanism
is enabled (true) or not (false). A read from the operational
datastore indicates whether this security mechanism is actually
running (true) or not (i.e., it indicates the operational state).
A data model that does not replicate parameters for running and
operational datastores can implement this as two separate
parameters. An implementation MAY choose to expose this parameter
as read-only ("ro").
babel-security-self-cred: Credentials this router presents to
participate in the enabled security mechanism. Any private key
component of a credential MUST NOT be readable. Adding and
deleting credentials MAY be allowed.
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babel-security-trust: A set of babel-credential-obj objects that
identify the credentials of routers whose Babel messages may be
trusted or of a certificate authority (CA) whose signing of a
router's credentials implies the router credentials can be
trusted, in the context of this security mechanism. How a
security mechanism interacts with this list is determined by the
mechanism. A security algorithm may do additional validation of
credentials, such as checking validity dates or revocation lists,
so presence in this list may not be sufficient to determine trust.
Adding and deleting credentials MAY be allowed.
babel-credvalid-log-enable: When written, it configures whether
logging should be enabled (true) or disabled (false). A read from
the running or intended datastore indicates the configured
administrative value of whether logging is enabled (true) or not
(false). A read from the operational datastore indicates whether
logging is actually running (true) or not (i.e., it indicates the
operational state). A data model that does not replicate
parameters for running and operational datastores can implement
this as two separate parameters. An implementation MAY choose to
expose this parameter as read-only ("ro").
babel-credvalid-log: Log entries that have the timestamp a message
containing credentials used for peer authentication (e.g., DTLS
Server Hello) was received on a Babel port, and the entire
received message (including Ethernet frame and IP headers, if
possible). An implementation must restrict the size of this log,
but how and what size is implementation-specific. If this log is
implemented, a mechanism to clear it SHOULD be provided.
3.6. Definition of babel-routes-obj
object {
ip-address ro babel-route-prefix;
int ro babel-route-prefix-length;
binary ro babel-route-router-id;
string ro babel-route-neighbor;
[int ro babel-route-received-metric;]
[int ro babel-route-calculated-metric;]
int ro babel-route-seqno;
ip-address ro babel-route-next-hop;
boolean ro babel-route-feasible;
boolean ro babel-route-selected;
} babel-routes-obj;
babel-route-prefix: Prefix (expressed in IP address format) for
which this route is advertised.
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babel-route-prefix-length: Length of the prefix for which this route
is advertised babel-route-router-id: router-id of the source
router for which this route is advertised.
babel-route-neighbor: Reference to the babel-neighbors entry for the
neighbor that advertised this route.
babel-route-received-metric: The metric with which this route was
advertised by the neighbor, or maximum value (infinity) to
indicate the route was recently retracted and is temporarily
unreachable (see Section 3.5.5 of [I-D.ietf-babel-rfc6126bis]).
This metric will be 0 (zero) if the route was not received from a
neighbor but was generated through other means. Either babel-
route-calculated-metric or babel-route-received-metric MUST be
provided.
babel-route-calculated-metric: A calculated metric for this route.
How the metric is calculated is implementation-specific. Maximum
value (infinity) indicates the route was recently retracted and is
temporarily unreachable (see Section 3.5.5 of
[I-D.ietf-babel-rfc6126bis]). Either babel-route-calculated-
metric or babel-route-received-metric MUST be provided.
babel-route-seqno: The sequence number with which this route was
advertised.
babel-route-next-hop: The next-hop address of this route. This will
be empty if this route has no next-hop address.
babel-route-feasible: A boolean flag indicating whether this route
is feasible, as defined in Section 3.5.1 of
[I-D.ietf-babel-rfc6126bis]).
babel-route-selected: A boolean flag indicating whether this route
is selected (i.e., whether it is currently being used for
forwarding and is being advertised).
4. Common Objects
4.1. Definition of babel-credential-obj
object {
credentials ro babel-cred;
} babel-credential-obj;
babel-cred: A credential, such as an X.509 certificate, a public
key, etc. used for signing and/or encrypting Babel messages.
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4.2. Definition of babel-log-obj
object {
datetime ro babel-log-time;
string ro babel-log-entry;
} babel-log-obj;
babel-log-time: The date and time (according to the device internal
clock setting, which may be a time relative to boot time, acquired
from NTP, configured by the user, etc.) when this log entry was
created.
babel-log-entry: The logged message, as a string of utf-8 encoded
hex characters.
5. Extending the Information Model
Implementations MAY extend this information model with other
parameters or objects. For example, an implementation MAY choose to
expose Babel route filtering rules by adding a route filtering object
with parameters appropriate to how route filtering is done in that
implementation. The precise means used to extend the information
model would be specific to the data model the implementation uses to
expose this information.
6. Security Considerations
This document defines a set of information model objects and
parameters that may be exposed to be visible from other devices, and
some of which may be configured. Securing access to and ensuring the
integrity of this data is in scope of and the responsibility of any
data model derived from this information model. Specifically, any
YANG [RFC7950] data model is expected to define security exposure of
the various parameters, and a [TR-181] data model will be secured by
the mechanisms defined for the management protocol used to transport
it.
This information model defines objects that can allow credentials
(for this device, for trusted devices, and for trusted certificate
authorities) to be added and deleted. Public keys and shared secrets
may be exposed through this model. This model requires that private
keys never be exposed. The Babel security mechanisms that make use
of these credentials (e.g., [I-D.ietf-babel-dtls],
[I-D.ietf-babel-hmac]) are expected to define what credentials can be
used with those mechanisms.
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7. IANA Considerations
This document defines a Babel Link Type registry for the values of
the babel-link-type and babel-supported-link-types parameters to be
listed under the Babel Routing Protocol registry.
Valid Babel Link Type names are normatively defined as
o MUST be at least 1 character and no more than 20 characters long
o MUST contain only US-ASCII [RFC0020] letters 'A' - 'Z' and 'a' -
'z', digits '0' - '9', and hyphens ('-', ASCII 0x2D or decimal 45)
o MUST contain at least one letter ('A' - 'Z' or 'a' - 'z')
o MUST NOT begin or end with a hyphen
o hyphens MUST NOT be adjacent to other hyphens
The rules for Link Type names, excepting the limit of 20 characters
maximum, are also expressed below (as a non-normative convenience)
using ABNF [RFC5234].
SRVNAME = *(1*DIGIT [HYPHEN]) ALPHA *([HYPHEN] ALNUM)
ALNUM = ALPHA / DIGIT ; A-Z, a-z, 0-9
HYPHEN = %x2D ; "-"
ALPHA = %x41-5A / %x61-7A ; A-Z / a-z [RFC5234]
DIGIT = %x30-39 ; 0-9 [RFC5234]
The allocation policy of this registry is Specification Required
[RFC8126].
The initial values in the "Babel Link Type" registry are:
+----------+-------------------------------------------+------------+
| Name | Used for Links Defined By | Reference |
+----------+-------------------------------------------+------------+
| ethernet | [IEEE-802.3-2018] | (this |
| | | document) |
| other | to be used when no link type information | (this |
| | available | document) |
| tunnel | to be used for a tunneled interface over | (this |
| | unknown physical link | document) |
| wireless | [IEEE-802.11-2016] | (this |
| | | document) |
| exp-* | Reserved for Experimental Use | (this |
| | | document) |
+----------+-------------------------------------------+------------+
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8. Acknowledgements
Juliusz Chroboczek, Toke Hoeiland-Joergensen, David Schinazi, Mahesh
Jethanandani, Acee Lindem, and Carsten Bormann have been very helpful
in refining this information model.
The language in the Notation section was mostly taken from [RFC8193].
9. References
9.1. Normative References
[I-D.ietf-babel-rfc6126bis]
Chroboczek, J. and D. Schinazi, "The Babel Routing
Protocol", draft-ietf-babel-rfc6126bis-05 (work in
progress), May 2018.
[RFC0020] Cerf, V., "ASCII format for network interchange", STD 80,
RFC 20, DOI 10.17487/RFC0020, October 1969,
<https://www.rfc-editor.org/info/rfc20>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
9.2. Informative References
[I-D.ietf-babel-dtls]
Decimo, A., Schinazi, D., and J. Chroboczek, "Babel
Routing Protocol over Datagram Transport Layer Security",
draft-ietf-babel-dtls-01 (work in progress), October 2018.
[I-D.ietf-babel-hmac]
Do, C., Kolodziejak, W., and J. Chroboczek, "Babel
Cryptographic Authentification", draft-ietf-babel-hmac-00
(work in progress), August 2018.
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[IEEE-802.11-2016]
"IEEE Standard 802.11-2016 - IEEE Standard for Information
Technology - Telecommunications and information exchange
between systems Local and metropolitan area networks -
Specific requirements - Part 11: Wireless LAN Medium
Access Control (MAC) and Physical Layer (PHY)
Specifications.".
[IEEE-802.3-2018]
"IEEE Standard 802.3-2018 - IEEE Approved Draft Standard
for Ethernet.".
[ISO.10646]
International Organization for Standardization,
"Information Technology - Universal Multiple-Octet Coded
Character Set (UCS)", ISO Standard 10646:2014, 2014.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
<https://www.rfc-editor.org/info/rfc3339>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<https://www.rfc-editor.org/info/rfc5234>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8193] Burbridge, T., Eardley, P., Bagnulo, M., and J.
Schoenwaelder, "Information Model for Large-Scale
Measurement Platforms (LMAPs)", RFC 8193,
DOI 10.17487/RFC8193, August 2017,
<https://www.rfc-editor.org/info/rfc8193>.
[TR-181] Broadband Forum, "Device Data Model",
<http://cwmp-data-models.broadband-forum.org/>.
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Appendix A. Open Issues
1. I want to get rid of the security log, because all Babel messages
(which should be defined as all messages to/from the udp-port)
are be logged by message-log. I don't like message log as it is.
I think if logging is enabled it should just write to a text
file. This will mean there also needs to be a means of
downloading/reading the log file.
2. Consider the following statistics: under interface object: sent
multicast Hello, sent updates, received Babel messages; under
neighbor object: sent unicast Hello, sent updates, sent IHU,
received Hello, received updates, received IHUs. Would also need
to enable/disable stats and clear stats.
3. Security section needs furter review
4. Commands to add and delete credentials, and parameters that allow
credential to be identified without allowing access to private
credential info
5. Check description of enable parameters to make sure ok for YANG
and TR-181. Closed by updating description to be useful for YANG
and TR-181, using language consistent with YANG descriptions.
6. Distinguish signed and unsigned integers?
7. Review new IANA Considerations section. Should ABNF be
normative?
Closed Issues:
1. Datatype of the router-id: Closed by introducing binary datatype
and using that for router-id
2. babel-neighbor-address as IPv6-only: Closed by leaving as is
(IPv4 and IPv6)
3. babel-implementation-version includes the name of the
implementation: Closed by adding "name" to description
4. Delete external-cost?: Closed by deleting.
5. Would it be useful to define some parameters for reporting
statistics or logs? [2 logs are now included. If others are
needed they need to be proposed. See Open Issues for additional
thoughts on logs and statistics.]
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6. Closed by defining base64 type and using it for all router IDs:
"babel-self-router-id: Should this be an opaque 64-bit value
instead of int?"
7. Closed as "No": Do we need a registry for the supported security
mechanisms? [Given the current limited set, and unlikelihood of
massive expansion, I don't think so. But we can if someone
wants it.]
8. This draft must be reviewed against draft-ietf-babel-rfc6126bis.
[I feel like this has been adequately done, but I could be
wrong.]
9. babel-interfaces-obj: Juliusz:"This needs further discussion, I
fear some of these are implementation details." [In the absence
of discussion, the current model stands. Note that all but
link-type and the neighbors sub-object are optional. If an
implementation does not have any of the optional elements then
it simply doesn't have them and that's fine.]
10. Would it be useful to define some parameters specifically for
security anomalies? [The 2 logs should be useful in identifying
security anomalies. If more is needed, someone needs to
propose.]
11. I created a basic security model. It's useful for single (or
no) active security mechanism (e.g., just HMAC, just DTLS, or
neither); but not multiple active (both HMAC and DTLS -- which
is not the same as HMAC of DTLS and would just mean that HMAC
would be used on all unencrypted messages -- but right now the
model doesn't allow for configuring HMAC of unencrypted messages
for routers without DTLS, while DTLS is used if possible). OK?
[No-one said otherwise.]
12. babel-external-cost may need more work. [if no comment, it will
be left as is]
13. babel-hello-[mu]cast-history: the Hello history is formated as
16 bits, per A.1 of 6126bis. Is that a too implementation
specific? [We also now have an optional-to-implement log of
received messages, and I made these optional. So maybe this is
ok?]
14. rxcost, txcost, cost: is it ok to model as integers, since
6126bis 2.1 says costs and metrics need not be integers. [I
have them as integers unless someone insists on something else.]
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15. For the security log, should it also log whether the credentials
were considered ok? [Right now it doesn't and I think that's ok
because if you log Hellos it was ok and if you don't it wasn't.]
16. Should Babel link types have an IANA registry? [Agreed to do
this at IETF 102.]
Appendix B. Change Log
Individual Drafts:
v00 2016-07-07 EBD: Initial individual draft version
v01 2017-03-13: Addressed comments received in 2016-07-15 email from
J. Chroboczek
Working group drafts:
v00 2017-07-03: Addressed points noted with "oops" in
https://www.ietf.org/proceedings/98/slides/slides-98-babel-babel-
information-model-00.pdf
v01 2018-01-02: Removed item from issue list that was agreed (in
Prague) not to be an issue. Added description of data types under
Notation section, and used these in all data types. Added babel-
security and babel-trust.
v02 2018-04-05:
* changed babel-version description to babel-implementation-
version
* replace optional babel-interface-seqno with optional babel-
mcast-hello-seqno and babel-ucast-hello-seqno
* replace optional babel-interface-hello-interval with optional
babel-mcast-hello-interval and babel-ucast-hello-interval
* remove babel-request-trigger-ack
* remove "babel-router-id: router-id of the neighbor"; note that
parameter had previously been removed but description had
accidentally not been removed
* added an optional "babel-cost" field to babel-neighbors object,
since the spec does not define how exactly the cost is computed
from rxcost/txcost
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* deleted babel-source-garbage-collection-time
* change babel-lossy-link to babel-link-type and make this an
enumeration; added at top level babel-supported-link-types so
which are supported by this implementation can be reported
* changes to babel-security-obj to allow self credentials to be
one or more instances of a credential object. Allowed trusted
credentials to include CA credentials; made some parameter name
changes
* updated references and Introduction
* added Overview section
* deleted babel-sources-obj
* added feasible Boolean to routes
* added section to briefly describe extending the information
model.
* deleted babel-route-neighbor
* tried to make definition of babel-interface-reference clearer
* added security and message logs
v03 2018-05-31:
* added reference to RFC 8174 (update to RFC 2119 on key words)
* applied edits to Introduction text per Juliusz email of
2018-04-06
* Deleted sentence in definition of "int" data type that said it
was also used for enumerations. Changed all enumerations to
strings. The only enumerations were for link types, which are
now "ethernet", "wireless", "tunnel", and "other".
* deleted [ip-address babel-mcast-group-ipv4;]
* babel-external-cost description changed
* babel-security-self-cred: Added "any private key component of a
credential MUST NOT be readable;"
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* hello-history parameters put recent Hello in most significant
bit and length of parameter is not constrained.
* babel-hello-seqno in neighbors-obj changed to babel-exp-mcast-
hello-seqno and babel-exp-ucast-hello-seqno
* added babel-route-neighbor back again. It was mistakenly
deleted
* changed babel-route-metric and babel-route-announced-metric to
babel-route-received-metric and babel-route-calculated-metric
* changed model of security object to put list of supported
mechanisms at top level and separate security object per
mechanism. This caused some other changes to the security
object
v04 2018-10-15:
* changed babel-mcast-group-ipv6 to babel-mcast-group
* link type parameters changed to point to newly defined registry
* babel-ucast-hello-interval moved to neighbor object
* babel-ucast-hello-seqno moved to neighbor object
* babel-neighbor-ihu-interval deleted
* in log descriptions, included statement that there SHOULD be
ability to clear logs
* added IANA registry for link types
* added "ro" and "rw" to tables for read-write and read-only
* added metric computation parameter to interface
Author's Address
Barbara Stark
AT&T
Atlanta, GA
US
Email: barbara.stark@att.com
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