Network Working Group A. Bierman
Internet-Draft YumaWorks
Intended status: Standards Track M. Bjorklund
Expires: August 29, 2013 Tail-f Systems
February 25, 2013
YANG Data Model for System Management
draft-ietf-netmod-system-mgmt-05
Abstract
This document defines a YANG data model for the configuration and
identification of the management system of a device.
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 http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
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 August 29, 2013.
Copyright Notice
Copyright (c) 2013 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
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
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 . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.1. Terms . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 3
2. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. System Identification . . . . . . . . . . . . . . . . . . 5
2.2. System Time Management . . . . . . . . . . . . . . . . . . 5
2.3. User Authentication . . . . . . . . . . . . . . . . . . . 5
3. System Data Model . . . . . . . . . . . . . . . . . . . . . . 6
3.1. System Identification . . . . . . . . . . . . . . . . . . 6
3.2. System Time Management . . . . . . . . . . . . . . . . . . 6
3.3. DNS Resolver Model . . . . . . . . . . . . . . . . . . . . 6
3.4. RADIUS Client Model . . . . . . . . . . . . . . . . . . . 7
3.5. User Authentication Model . . . . . . . . . . . . . . . . 7
3.5.1. SSH Public Key Authentication . . . . . . . . . . . . 8
3.5.2. Local User Password Authentication . . . . . . . . . . 8
3.5.3. RADIUS Password Authentication . . . . . . . . . . . . 8
3.6. System Control . . . . . . . . . . . . . . . . . . . . . . 9
4. System YANG module . . . . . . . . . . . . . . . . . . . . . . 10
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
6. Security Considerations . . . . . . . . . . . . . . . . . . . 27
7. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.1. 00-01 . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.2. 01-02 . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.3. 02-03 . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.4. 03-04 . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.5. 04-05 . . . . . . . . . . . . . . . . . . . . . . . . . . 29
8. Normative References . . . . . . . . . . . . . . . . . . . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 32
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1. Introduction
This document defines a YANG [RFC6020] data model for the
configuration and identification of the management system of a
device.
Devices that are managed by NETCONF and perhaps other mechanisms have
common properties that need to be configured and monitored in a
standard way.
The "ietf-system" YANG module defined in this document provides the
following features:
o system administrative data configuration
o system identification monitoring
o system time-of-day configuration and monitoring
o user authentication configuration
o local users configuration
1.1. Terminology
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14, [RFC2119].
1.1.1. Terms
The following terms are used within this document:
o system: This term refers to the embodiment of the entire set of
management interfaces that a single NETCONF server is supporting
at a given moment. The set of physical entities managed by a
single NETCONF server can be static or it can change dynamically.
1.2. Tree Diagrams
A simplified graphical representation of the data model is used in
this document. The meaning of the symbols in these diagrams is as
follows:
o Brackets "[" and "]" enclose list keys.
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o Abbreviations before data node names: "rw" means configuration
(read-write) and "ro" state data (read-only).
o Symbols after data node names: "?" means an optional node and "*"
denotes a "leaf-list".
o Parentheses enclose choice and case nodes, and case nodes are also
marked with a colon (":").
o Ellipsis ("...") stands for contents of subtrees that are not
shown.
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2. Objectives
2.1. System Identification
There are many common properties used to identify devices, operating
systems, software versions, etc. that need to be supported in the
system data module. These objects are defined as operational data
and intended to be specific to the device vendor.
Some user-configurable administrative strings are also provided such
as the system location and description.
2.2. System Time Management
The management of the date and time used by the system need to be
supported. Use of one or more NTP servers to automatically set the
system date and time need to be possible. Utilization of the
Timezone database [RFC6557] also need to be supported.
2.3. User Authentication
The authentication mechanism need to support password authentication
over RADIUS, to support deployment scenarios with centralized
authentication servers. Additionally, local users need to be
supported, for scenarios when no centralized authentication server
exists, or for situations where the centralized authentication server
cannot be reached from the device.
Since the mandatory transport protocol for NETCONF is SSH [RFC6242]
the authentication model need to support SSH's "publickey" and
"password" authentication methods [RFC4252].
The model for authentication configuration should be flexible enough
to support authentication methods defined by other standard documents
or by vendors.
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3. System Data Model
3.1. System Identification
The data model for system identification has the following structure:
+--rw system
+--rw contact? string
+--rw name? string
+--rw location? string
+--ro platform
+--ro os-name? string
+--ro os-release? string
+--ro os-version? string
+--ro machine? string
+--ro nodename? string
3.2. System Time Management
The data model for system time management has the following
structure:
+--rw system
+--rw clock
| +--ro current-datetime? yang:date-and-time
| +--ro boot-datetime? yang:date-and-time
| +--rw (timezone)?
| +--:(timezone-location)
| | +--rw timezone-location? string
| +--:(timezone-utc-offset)
| +--rw timezone-utc-offset? int16
+--rw ntp
+--rw use-ntp? boolean
+--rw ntp-server [address]
+--rw association-type? enumeration
+--rw address inet:host
+--rw enabled? boolean
+--rw iburst? boolean
+--rw prefer? boolean
3.3. DNS Resolver Model
The data model for configuration of the DNS resolver has the
following structure:
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+--rw system
+--rw dns
+--rw search* inet:host
+--rw server* inet:ip-address
+--rw options
+--rw timeout? uint8
+--rw attempts? uint8
3.4. RADIUS Client Model
The data model for configuration of the RADIUS client has the
following structure:
+--rw system
+--rw radius
+--rw server [address]
| +--rw address inet:host
| +--rw authentication-port? inet:port-number
| +--rw shared-secret? string
+--rw options
+--rw timeout? uint8
+--rw attempts? uint8
3.5. User Authentication Model
This document defines three authentication methods for use with
NETCONF:
o publickey for local users over SSH
o password for local users over any transport
o password for RADIUS users over any transport
Additional methods can be defined by other standard documents or by
vendors.
This document defines two optional YANG features, "local-users" and
"radius-authentication", which the server advertises to indicate
support for configuring local users on the device, and support for
using RADIUS for authentication, respectively.
The authentication parameters defined in this document are primarily
used to configure authentication of NETCONF users, but MAY also be
used by other interfaces, e.g., a Command Line Interface or a Web-
based User Interface.
The data model for user authentication has the following structure:
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+--rw system
+--rw authentication
+--rw user-authentication-order* identityref
+--rw user [name]
+--rw name string
+--rw password? crypt-hash
+--rw ssh-key [name]
+--rw name string
+--rw algorithm? string
+--rw key-data? binary
3.5.1. SSH Public Key Authentication
If the NETCONF server advertises the "local-users" feature,
configuration of local users and their SSH public keys is supported
in the /system/authentication/user list.
Public key authentication is requested by the SSH client. If the
"local-users" feature is supported, then when a NETCONF client starts
an SSH session towards the server using the "publickey"
authentication "method name" [RFC4252], the SSH server looks up the
user name given in the SSH authentication request in the /system/
authentication/user list, and verifies the key as described in
[RFC4253].
3.5.2. Local User Password Authentication
If the NETCONF server advertises the "local-users" feature,
configuration of local users and their passwords is supported in the
/system/authentication/user list.
For NETCONF transport protocols that support password authentication,
the leaf-list "user-authentication-order" is used to control if local
user password authentication should be used.
In SSH, password authentication is requested by the client. Other
NETCONF transport protocols MAY also support password authentication.
When local user password authentication is requested, the NETCONF
transport looks up the user name provided by the client in the
/system/ authentication/user list, and verifies the password.
3.5.3. RADIUS Password Authentication
If the NETCONF server advertises the "radius-authentication" feature,
the device supports user authentication using RADIUS.
For NETCONF transport protocols that support password authentication,
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the leaf-list "user-authentication-order" is used to control if
RADIUS password authentication should be used.
In SSH, password authentication is requested by the client. Other
NETCONF transport protocols MAY also support password authentication.
3.6. System Control
Two protocol operations are included to restart or shutdown the
system. The 'system-restart' operation can be used to restart the
entire system (not just the NETCONF server). The 'system-shutdown'
operation can be used to power off the entire system.
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4. System YANG module
This YANG module imports YANG extensions from [RFC6536], and imports
YANG types from [RFC6021] and [I-D.lange-netmod-iana-timezones]. It
also references [RFC1321], [RFC2865], [RFC3418], [RFC5607],
[IEEE-1003.1-2008], and [FIPS.180-3.2008].
RFC Ed.: update the date below with the date of RFC publication and
remove this note.
<CODE BEGINS> file "ietf-system@2013-02-25.yang"
module ietf-system {
namespace "urn:ietf:params:xml:ns:yang:ietf-system";
prefix "sys";
import ietf-yang-types {
prefix yang;
}
import ietf-inet-types {
prefix inet;
}
import ietf-netconf-acm {
prefix nacm;
}
import iana-timezones {
prefix ianatz;
}
organization
"IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
WG Chair: David Kessens
<mailto:david.kessens@nsn.com>
WG Chair: Juergen Schoenwaelder
<mailto:j.schoenwaelder@jacobs-university.de>
Editor: Andy Bierman
<mailto:andy@yumaworks.com>
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Editor: Martin Bjorklund
<mailto:mbj@tail-f.com>";
description
"This module contains a collection of YANG definitions for the
configuration and identification of the management system of a
device.
Copyright (c) 2012 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: remove this note
// Note: extracted from draft-ietf-netmod-system-mgmt-05.txt
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision "2013-02-25" {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Data Model for System Management";
}
/*
* Typedefs
*/
typedef crypt-hash {
type string {
pattern "$0$.*|$(1|5|6)$[a-zA-Z0-9./]{2,16}$.*";
}
description
"The crypt-hash type is used to store passwords using
a hash function. This type is implemented in various UNIX
systems as the function crypt(3).
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When a clear text value is set to a leaf of this type, the
server calculates a password hash, and stores the result
in the datastore. Thus, the password is never stored in
clear text.
When a leaf of this type is read, the stored password hash is
returned.
A value of this type matches one of the forms:
$0$<clear text password>
$<id>$<salt>$<password hash>
The '$0$' prefix signals that the value is clear text. When
such a value is received by the server, a hash value is
calculated, and the string '$<id>$<salt>$' is prepended to the
result, where <salt> is a random 2-16 characters long salt
used to generate the digest. This value is stored in the
configuration data store.
If a value starting with '$<id>$<salt>$' is received, the
server knows that the value already represents a hashed value,
and stores it as is in the data store.
When a server needs to verify a password given by a user, it
finds the stored password hash string for that user, extracts
the salt, and calculates the hash with the salt and given
password as input. If the calculated hash value is the same
as the stored value, the password given by the client is
correct.
This type defines the following hash functions:
id | hash function | feature
---+---------------+-------------------
1 | MD5 | crypt-hash-md5
5 | SHA-256 | crypt-hash-sha-256
6 | SHA-512 | crypt-hash-sha-512
The server indicates support for the different hash functions
by advertising the corresponding feature.";
reference
"IEEE Std 1003.1-2008 - crypt() function
Wikipedia: http://en.wikipedia.org/wiki/Crypt_(Unix)
RFC 1321: The MD5 Message-Digest Algorithm
FIPS.180-3.2008: Secure Hash Standard";
}
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/*
* Features
*/
feature radius {
description
"Indicates that the device can be configured as a RADIUS
client.";
reference
"RFC 2865: Remote Authentication Dial In User Service "
+ "(RADIUS)";
}
feature authentication {
description
"Indicates that the device can be configured
to do authentication of users.";
}
feature local-users {
if-feature authentication;
description
"Indicates that the device supports
local user authentication.";
}
feature radius-authentication {
if-feature radius;
if-feature authentication;
description
"Indicates that the device supports user authentication over
RADIUS.";
reference
"RFC 2865: Remote Authentication Dial In User Service (RADIUS)
RFC 5607: Remote Authentication Dial-In User Service (RADIUS)
Authorization for Network Access Server (NAS)
Management";
}
feature crypt-hash-md5 {
description
"Indicates that the device supports the MD5
hash function in 'crypt-hash' values";
reference "RFC 1321: The MD5 Message-Digest Algorithm";
}
feature crypt-hash-sha-256 {
description
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"Indicates that the device supports the SHA-256
hash function in 'crypt-hash' values";
reference "FIPS.180-3.2008: Secure Hash Standard";
}
feature crypt-hash-sha-512 {
description
"Indicates that the device supports the SHA-512
hash function in 'crypt-hash' values";
reference "FIPS.180-3.2008: Secure Hash Standard";
}
feature ntp {
description
"Indicates that the device can be configured
to use one or more NTP servers to set the
system date and time.";
}
feature timezone-location {
description
"Indicates that the local timezone on the device
can be configured to use the TZ database
to set the timezone and manage daylight savings time.";
reference
"TZ Database http://www.twinsun.com/tz/tz-link.htm
Maintaining the Timezone Database
RFC 6557 (BCP 175)";
}
/*
* Identities
*/
identity authentication-method {
description
"Base identity for user authentication methods.";
}
identity radius {
base authentication-method;
description
"Indicates user authentication using RADIUS.";
reference
"RFC 2865: Remote Authentication Dial In User Service (RADIUS)
RFC 5607: Remote Authentication Dial-In User Service (RADIUS)
Authorization for Network Access Server (NAS)
Management";
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}
identity local-users {
base authentication-method;
description
"Indicates password-based authentication of locally
configured users.";
}
identity radius-authentication-type {
description
"Base identity for RADIUS authentication types.";
}
identity radius-pap {
base radius-authentication-type;
description
"The device requests PAP authentication from the RADIUS
server.";
reference
"RFC 2865: Remote Authentication Dial In User Service";
}
identity radius-chap {
base radius-authentication-type;
description
"The device requests CHAP authentication from the RADIUS
server.";
reference
"RFC 2865: Remote Authentication Dial In User Service";
}
/*
* Top-level container
*/
container system {
description
"System group configuration.";
leaf contact {
type string {
length "0..255";
}
description
"The administrator contact information for the system.";
reference
"RFC 3418 - Management Information Base (MIB) for the
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Simple Network Management Protocol (SNMP)
SNMPv2-MIB.sysContact";
}
leaf name {
type string {
length "0..255";
}
description
"The administratively assigned system name.";
reference
"RFC 3418 - Management Information Base (MIB) for the
Simple Network Management Protocol (SNMP)
SNMPv2-MIB.sysName";
}
leaf location {
type string {
length "0..255";
}
description
"The system location";
reference
"RFC 3418 - Management Information Base (MIB) for the
Simple Network Management Protocol (SNMP)
SNMPv2-MIB.sysLocation";
}
container platform {
config false;
description
"Contains vendor-specific information for
identifying the system platform and operating system.";
reference
"IEEE Std 1003.1-2008 - sys/utsname.h";
leaf os-name {
type string;
description
"The name of the operating system in use,
for example 'Linux'";
reference
"IEEE Std 1003.1-2008 - utsname.sysname";
}
leaf os-release {
type string;
description
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"The current release level of the operating
system in use. This string MAY indicate
the OS source code revision.";
reference
"IEEE Std 1003.1-2008 - utsname.release";
}
leaf os-version {
type string;
description
"The current version level of the operating
system in use. This string MAY indicate
the specific OS build date and target variant
information.";
reference
"IEEE Std 1003.1-2008 - utsname.version";
}
leaf machine {
type string;
description
"A vendor-specific identifier string representing
the hardware in use.";
reference
"IEEE Std 1003.1-2008 - utsname.machine";
}
leaf nodename {
type string;
description
"The host name of this system.";
reference
"IEEE Std 1003.1-2008 - utsname.nodename";
}
}
container clock {
description
"Configuration and monitoring of the system
date and time properties.";
leaf current-datetime {
type yang:date-and-time;
config false;
description
"The current system date and time.";
}
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leaf boot-datetime {
type yang:date-and-time;
config false;
description
"The system date and time when the NETCONF
server last restarted.";
}
choice timezone {
description
"The system timezone information.";
leaf timezone-location {
if-feature timezone-location;
type ianatz:iana-timezone;
description
"The TZ database location identifier string
to use for the system, such as 'Europe/Stockholm'.";
}
leaf timezone-utc-offset {
type int16 {
range "-1500 .. 1500";
}
units "minutes";
description
"The number of minutes to add to UTC time to
identify the timezone for this system.
For example, 'UTC - 8:00 hours' would be
represented as '-480'. Note that automatic
daylight savings time adjustment is not provided,
if this object is used.";
}
}
}
container ntp {
if-feature ntp;
description
"Configuration of the NTP client.";
leaf use-ntp {
type boolean;
default true;
description
"Indicates that the system should attempt
to synchronize the system clock with an
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NTP server from the 'ntp-server' list.";
}
list ntp-server {
key address;
description
"List of NTP servers to use for
system clock synchronization. If 'use-ntp'
is 'true', then the system will attempt to
contact and utilize the specified NTP servers.";
leaf association-type {
type enumeration {
enum server {
description
"Use server association mode. This device
is not expected to synchronize with the
configured NTP server.";
}
enum peer {
description
"Use peer association mode. This device
may be expected to synchronize with the
configured NTP server.";
}
enum pool {
description
"Use pool association mode. This device
is not expected to synchronize with the
configured NTP server.";
}
}
default server;
description
"The desired association type for this NTP server.";
}
leaf address {
type inet:host;
description
"The IP address or domain name of the NTP server.";
}
leaf enabled {
type boolean;
default true;
description
"Indicates whether this server is enabled for use or
not.";
}
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leaf iburst {
type boolean;
default false;
description
"Indicates whether this server should enable burst
synchronization or not.";
}
leaf prefer {
type boolean;
default false;
description
"Indicates whether this server should be preferred
or not.";
}
}
}
container dns {
description
"Configuration of the DNS resolver.";
leaf-list search {
type inet:host;
ordered-by user;
description
"An ordered list of domains to search when resolving
a host name.";
}
leaf-list server {
type inet:ip-address;
ordered-by user;
description
"Addresses of the name servers that the resolver should
query.
Implementations MAY limit the number of entries in this
leaf list.";
}
container options {
description
"Resolver options. The set of available options has been
limited to those that are generally available across
different resolver implementations, and generally
useful.";
leaf timeout {
type uint8 {
range "1..max";
}
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units "seconds";
default "5";
description
"The amount of time the resolver will wait for a
response from a remote name server before
retrying the query via a different name server.";
}
leaf attempts {
type uint8 {
range "1..max";
}
default "2";
description
"The number of times the resolver will send a query to
its name servers before giving up and returning an
error to the calling application.";
}
}
}
container radius {
if-feature radius;
description
"Configuration of the RADIUS client.";
list server {
key address;
ordered-by user;
description
"List of RADIUS servers used by the device.";
leaf address {
type inet:host;
description
"The address of the RADIUS server.";
}
leaf authentication-port {
type inet:port-number;
default "1812";
description
"The port number of the RADIUS server.";
}
leaf shared-secret {
type string;
nacm:default-deny-all;
description
"The shared secret which is known to both the RADIUS
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client and server.";
reference
"RFC 2865: Remote Authentication Dial In User Service";
}
leaf authentication-type {
type identityref {
base radius-authentication-type;
}
default radius-pap;
description
"The authentication type requested from the RADIUS
server.";
}
}
container options {
description
"RADIUS client options.";
leaf timeout {
type uint8 {
range "1..max";
}
units "seconds";
default "5";
description
"The number of seconds the device will wait for a
response from a RADIUS server before trying with a
different server.";
}
leaf attempts {
type uint8 {
range "1..max";
}
default "2";
description
"The number of times the device will send a query to
the RADIUS servers before giving up.";
}
}
}
container authentication {
nacm:default-deny-write;
if-feature authentication;
description
"The authentication configuration subtree.";
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leaf-list user-authentication-order {
type identityref {
base authentication-method;
}
must '(. = "sys:radius" and ../../radius/server) or'
+ '(. != "sys:radius")' {
error-message
"When 'radius' is used, a radius server"
+ " must be configured.";
}
ordered-by user;
description
"When the device authenticates a user with
a password, it tries the authentication methods in this
leaf-list in order. If authentication with one method
fails, the next method is used. If no method succeeds,
the user is denied access.
If the 'radius-authentication' feature is advertised by
the NETCONF server, the 'radius' identity can be added to
this list.
If the 'local-users' feature is advertised by the
NETCONF server, the 'local-users' identity can be
added to this list.";
}
list user {
if-feature local-users;
key name;
description
"The list of local users configured on this device.";
leaf name {
type string;
description
"The user name string identifying this entry.";
}
leaf password {
type crypt-hash;
description
"The password for this entry.";
}
list ssh-key {
key name;
description
"A list of public SSH keys for this user.";
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reference
"RFC 4253: The Secure Shell (SSH) Transport Layer
Protocol";
leaf name {
type string;
description
"An arbitrary name for the ssh key.";
}
leaf algorithm {
type string;
description
"The public key algorithm name for this ssh key.
Valid values are the values in the IANA Secure Shell
(SSH) Protocol Parameters registry, Public Key
Algorithm Names";
reference
"IANA Secure Shell (SSH) Protocol Parameters registry,
Public Key Algorithm Names";
}
leaf key-data {
type binary;
description
"The binary key data for this ssh key.";
}
}
}
}
}
rpc set-current-datetime {
nacm:default-deny-all;
description
"Set the /system/clock/current-datetime leaf
to the specified value.
If the system is using NTP (e.g., /system/ntp/use-ntp
is set to 'true'), then this operation will
fail with error-tag 'operation-failed',
and error-app-tag value of 'ntp-active'";
input {
leaf current-datetime {
type yang:date-and-time;
mandatory true;
description
"The current system date and time.";
}
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}
}
rpc system-restart {
nacm:default-deny-all;
description
"Request that the entire system be restarted immediately.
A server SHOULD send an rpc reply to the client before
restarting the system.";
}
rpc system-shutdown {
nacm:default-deny-all;
description
"Request that the entire system be shut down immediately.
A server SHOULD send an rpc reply to the client before
shutting down the system.";
}
}
<CODE ENDS>
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5. IANA Considerations
This document registers one URI in the IETF XML registry [RFC3688].
Following the format in RFC 3688, the following registration is
requested to be made.
URI: urn:ietf:params:xml:ns:yang:ietf-system
Registrant Contact: The NETMOD WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
This document registers one YANG module in the YANG Module Names
registry [RFC6020].
name: ietf-system
namespace: urn:ietf:params:xml:ns:yang:ietf-system
prefix: sys
reference: RFC XXXX
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6. Security Considerations
The YANG module defined in this memo is designed to be accessed via
the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the
secure transport layer and the mandatory-to-implement secure
transport is SSH [RFC6242].
There are a number of data nodes defined in this YANG module which
are writable/creatable/deletable (i.e., config true, which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., edit-config)
to these data nodes without proper protection can have a negative
effect on network operations. These are the subtrees and data nodes
and their sensitivity/vulnerability:
o /system/clock/timezone: This choice contains the objects used to
control the timezone used by the device.
o /system/ntp: This container contains the objects used to control
the Network Time Protocol servers used by the device.
o /system/dns: This container contains the objects used to control
the Domain Name System servers used by the device.
o /system/radius: This container contains the objects used to
control the Remote Authentication Dial-In User Service servers
used by the device.
o /system/authentication/user-authentication-order: This leaf
controls how user login attempts are authenticated by the device.
o /system/authentication/user: This list contains the local users
enabled on the system.
Some of the readable data nodes in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. These are the subtrees and data
nodes and their sensitivity/vulnerability:
o /system/platform: This container has objects which may help
identify the specific NETCONF server and/or operating system
implementation used on the device.
Some of the RPC operations in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control access to these operations. These are the
operations and their sensitivity/vulnerability:
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o set-current-datetime: Changes the current date and time on the
device.
o system-restart: Reboots the device.
o system-shutdown: Shuts down the device.
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7. Change Log
-- RFC Ed.: remove this section before publication.
7.1. 00-01
o added configuration-source identities
o added configuration-source leaf to ntp and dns (via grouping) to
choose configuration source
o added association-type, iburst, prefer, and true leafs to the ntp-
server list
o extended the ssh keys for a user to a list of keys. support all
defined key algorithms, not just dsa and rsa
o clarified timezone-utc-offset description-stmt
o removed '/system/ntp/server/true' leaf from data model
7.2. 01-02
o added default-stmts to ntp-server/iburst and ntp-server/prefer
leafs
o changed timezone-location leaf to use iana-timezone typedef
instead of a string
7.3. 02-03
o removed configuration-source identities and leafs
7.4. 03-04
o removed ndots dns resolver option
o added radius-authentication-type identity, and identities for pap
and chap, and a leaf to control which authentication type to use
when communicating with the radius server
o made 0 an invalid value for timeouts and attempts
7.5. 04-05
o updated tree diagram explanation text
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8. Normative References
[FIPS.180-3.2008]
National Institute of Standards and Technology, "Secure
Hash Standard", FIPS PUB 180-3, October 2008, <http://
csrc.nist.gov/publications/fips/fips180-3/
fips180-3_final.pdf>.
[I-D.lange-netmod-iana-timezones]
Lange, J., "IANA Timezone Database YANG Module",
draft-lange-netmod-iana-timezones-01 (work in progress),
June 2012.
[IEEE-1003.1-2008]
Institute of Electrical and Electronics Engineers,
"POSIX.1-2008", IEEE Standard 1003.1, March 2008.
[RFC1321] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321,
April 1992.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)",
RFC 2865, June 2000.
[RFC3418] Presuhn, R., "Management Information Base (MIB) for the
Simple Network Management Protocol (SNMP)", STD 62,
RFC 3418, December 2002.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC4252] Ylonen, T. and C. Lonvick, "The Secure Shell (SSH)
Authentication Protocol", RFC 4252, January 2006.
[RFC4253] Ylonen, T. and C. Lonvick, "The Secure Shell (SSH)
Transport Layer Protocol", RFC 4253, January 2006.
[RFC5607] Nelson, D. and G. Weber, "Remote Authentication Dial-In
User Service (RADIUS) Authorization for Network Access
Server (NAS) Management", RFC 5607, July 2009.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the
Network Configuration Protocol (NETCONF)", RFC 6020,
October 2010.
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[RFC6021] Schoenwaelder, J., "Common YANG Data Types", RFC 6021,
October 2010.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, June 2011.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, June 2011.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
March 2012.
[RFC6557] Lear, E. and P. Eggert, "Procedures for Maintaining the
Time Zone Database", BCP 175, RFC 6557, February 2012.
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Authors' Addresses
Andy Bierman
YumaWorks
Email: andy@yumaworks.com
Martin Bjorklund
Tail-f Systems
Email: mbj@tail-f.com
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