NETMOD WG
Internet Engineering Task Force (IETF) J. Clarke, Ed.
Internet-Draft
Request for Comments: 9742 Cisco
Intended status:
Category: Standards Track M. Jethanandani, Ed.
Expires: 22 March 2025
ISSN: 2070-1721 Kloud Services
C. Wildes, Ed.
Cisco Systems Inc.
K. Koushik, Ed.
Verizon Wireless
18 September 2024
March 2025
A YANG Data Model for Syslog Configuration
draft-ietf-netmod-syslog-model-33
Abstract
This document defines a YANG data model for the configuration of a
syslog process. It is intended that this data model be used by
vendors who implement syslog collectors in their systems.
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 an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list It represents the consensus of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid the IETF community. It has
received public review and has been approved for a maximum publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of six months RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be updated, replaced, or obsoleted by other documents obtained 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 22 March 2025.
https://www.rfc-editor.org/info/rfc9742.
Copyright Notice
Copyright (c) 2024 2025 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 (https://trustee.ietf.org/
license-info)
(https://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 Revised BSD License text as described in Section 4.e of the
Trust Legal Provisions and are provided without warranty as described
in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. NMDA Compliance . . . . . . . . . . . . . . . . . . . . . . . 4
4. Editorial Note (To be removed by RFC Editor) . . . . . . . . 4
5. Design of the Syslog Model . . . . . . . . . . . . . . . . . 4
5.1.
4.1. Syslog Module . . . . . . . . . . . . . . . . . . . . . . 6
6.
5. Syslog YANG Module . . . . . . . . . . . . . . . . . . . . . 9
6.1.
5.1. The ietf-syslog Module . . . . . . . . . . . . . . . . . 9
7.
6. Usage Examples . . . . . . . . . . . . . . . . . . . . . . . 29
7.1.
6.1. Syslog Configuration for Severity Critical . . . . . . . 29
7.2.
6.2. Remote Syslog Configuration . . . . . . . . . . . . . . . 30
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 31
9.
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 31
9.1.
7.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 32
9.2.
7.2. The YANG Module Names Registry . . . . . . . . . . . . . 32
10.
8. Security Considerations . . . . . . . . . . . . . . . . . . . 32
11.
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 33
11.1.
9.1. Normative References . . . . . . . . . . . . . . . . . . 33
11.2.
9.2. Informative References . . . . . . . . . . . . . . . . . 36
Appendix A. Tree Diagrams . . . . . . . . . . . . . . . . . . . 36
A.1. Complete Tree Diagram . . . . . . . . . . . . . . . . . . 36
Appendix B. Implementer Guidelines . . . . . . . . . . . . . . . 48
B.1. Extending Facilities . . . . . . . . . . . . . . . . . . 48
B.2. Syslog Terminal Output . . . . . . . . . . . . . . . . . 49
B.3. Syslog File Naming Convention . . . . . . . . . . . . . . 50
Acknowledgements
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 50
1. Introduction
This document defines a YANG [RFC7950] configuration data model that
may be used to configure the syslog feature running on a system.
YANG data models can be used with network management protocols such
as NETCONF [RFC6241] to install, manipulate, and delete the
configuration of network devices.
The data model makes use of the YANG "feature" construct which that allows
implementations to support only those syslog features that lie within
their capabilities.
This module can be used to configure the syslog application
conceptual layers as implemented on the syslog collector.
Essentially, a syslog process receives messages (from the kernel,
processes, applications applications, or other syslog processes) and processes
them. The processing may involve logging to a local file, and/or displaying
on console, and/or relaying to syslog processes on other machines.
The processing process is determined by the "facility" that originated the
message and the "severity" assigned to the message by the facility.
Such definitions of syslog protocol are defined in [RFC5424] , and are
used in this RFC.
The YANG data model in this document conforms to the Network
Management Datastore Architecture defined in [RFC8342].
1.1. Requirements Language
The key words "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] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Terminology
The following terms are used throughout this document:
*
Originator: an An "originator" refers to an entity that generates
syslog content to be carried in a message. The term is defined in
[RFC5424]
*
[RFC5424].
Relay: A "relay" is an entity that forwards syslog messages. It
accepts messages from originators or other relays and sends them
to collectors or other relays. The term is defined in [RFC5424]
* [RFC5424].
Collector: A "collector" gathers syslog content for further
analysis. The term is defined in [RFC5424].
*
Action: The term "action" refers to the processing process that takes place for
each syslog message received.
3. NMDA Compliance
The YANG data model in this document conforms to the Network
Management Datastore Architecture (NMDA) defined in [RFC8342] . [RFC8342].
4. Editorial Note (To be removed by RFC Editor)
This document contains many placeholder values that need to be
replaced with finalized values at the time of publication. This note
summarizes all of the substitutions that are needed. No other RFC
Editor instructions are specified elsewhere in this document.
Artwork in this document contains shorthand references to drafts in
progress. Please apply the following replacements:
* I-D.ietf-netconf-crypto-types --> the assigned RFC value for
draft-ietf-netconf-crypto-types
* I-D.ietf-netconf-tls-client-server --> the assigned RFC value for
draft-ietf-netconf-tls-client-server
* zzzz --> the assigned RFC value for this draft
5. Design of the Syslog Model
The syslog model was designed by comparing various syslog features
implemented by various vendors' vendors in different implementations.
The module defines leafs that are common across implementations. Its
simple design is meant to offer maximum flexibility. However, not
all optional features defined in this document are present in all
vendor implementations. Vendors therefore, Therefore, vendors need to use the feature
statements to specify the optional features they support. At the
same time, vendors can augment the model to add proprietary features.
Extending Facilities (Appendix B.1) shows an examples of how that can
be realized.
Syslog consists of originators and collectors. The following diagram
shows syslog messages flowing from originators, originators to collectors where
filtering can take place.
Originators
+-------------+ +-------------+ +-------------+ +-------------+
| Various | | OS | | | | Remote |
| Components | | Kernel | | Line Cards | | Servers |
+-------------+ +-------------+ +-------------+ +-------------+
+-------------+ +-------------+ +-------------+ +-------------+
| SNMP | | Interface | | Standby | | Syslog |
| Events | | Events | | Supervisor | | Itself |
+-------------+ +-------------+ +-------------+ +-------------+
| |
+----------------------------------------------------------------+
|
|
|
|
+-------------+--------------+
| | |
v v v
Collectors
+----------+ +----------+ +----------------+
| | | Log | |Remote Relay(s)/|
| Console | | File(s) | |Collector(s) |
+----------+ +----------+ +----------------+
Figure 1. 1: Syslog Processing Flow
Collectors are configured using the leaves in the syslog model
"actions" container which that correspond to each message collector:
* console
* log file(s)
* remote relay(s)/collector(s)
Within each action, a selector is used to filter syslog messages. A
selector consists of a list of one or more filters specified by
facility-severity pairs, and, if supported via the select-match
feature, an optional regular expression pattern match that is
performed on the [RFC5424] field.
A syslog message is processed if:
There is an element of facility-list (F, S) where
the message facility matches F
and the message severity matches S
and/or the message text matches the regex pattern (if it
is present)
The facility is one of a specific syslog-facility, syslog-facility or all facilities.
The model offers the ability to select a transport that a user might
want to use for a remote relay or collector. The choice is between
using UDP, UDP or TLS based TLS-based sessions. The user can configure multiple
relays or collectors, but they have to use the same transport.
The severity is one of type syslog-severity, all severities, or none.
None is a special case that can be used to disable a filter. When
filtering severity, the default comparison is that messages of the
specified severity and higher are selected to be logged. This is
shown in the model as "default equals-or-higher". This behavior can
be altered if the select-adv-compare feature is enabled to specify a
compare operation and an action. Compare operations are: "equals" to
select messages with this single severity, or "equals-or-higher" to
select messages of the specified severity and higher. Actions are
used to log the message, block the message, or stop the message from
being logged.
Many vendors extend the list of facilities available for logging in
their implementation. An example is included in Extending Facilities "Extending
Facilities" (Appendix B.1).
5.1.
4.1. Syslog Module
A simplified tree representation of the data model is used in this
document. Please see [RFC8340] for tree diagram notation.
module: ietf-syslog
+--rw syslog!
+--rw actions
+--rw console! {console-action}?
| +--rw filter
| | +--rw facility-list* [facility severity]
| | +--rw facility union
| | +--rw severity union
| | +--rw advanced-compare {select-adv-compare}?
| | +--rw compare? enumeration
| | +--rw action? identityref
| +--rw pattern-match? string {select-match}?
+--rw file {file-action}?
| +--rw log-file* [name]
| +--rw name inet:uri
| +--rw filter
| | +--rw facility-list* [facility severity]
| | +--rw facility union
| | +--rw severity union
| | +--rw advanced-compare {select-adv-compare}?
| | +--rw compare? enumeration
| | +--rw action? identityref
| +--rw pattern-match? string {select-match}?
| +--rw structured-data? boolean {structured-data}?
| +--rw file-rotation
| +--rw number-of-files? uint32 {file-limit-size}?
| +--rw max-file-size? uint32 {file-limit-size}?
| +--rw rollover? uint32
| | {file-limit-duration}?
| +--rw retention? uint32
| {file-limit-duration}?
+--rw remote {remote-action}?
+--rw destination* [name]
+--rw name string
+--rw (transport)
| +--:(udp)
| | +--rw udp
| | +--rw udp* [address]
| | +--rw address inet:host
| | +--rw port? inet:port-number
| +--:(tls)
| +--rw tls
| +--rw tls* [address]
| +--rw address inet:host
| +--rw port?
| | inet:port-number
| +--rw client-identity!
| | +--rw (auth-type)
| | ...
| +--rw server-authentication
| | +--rw ca-certs! {server-auth-x509-cert}?
| | | ...
| | +--rw ee-certs! {server-auth-x509-cert}?
| | | ...
| | +--rw raw-public-keys!
| | | {server-auth-raw-public-key}?
| | | ...
| | +--rw tls12-psks? empty
| | | {server-auth-tls12-psk}?
| | +--rw tls13-epsks? empty
| | {server-auth-tls13-epsk}?
| +--rw hello-params {tlscmn:hello-params}?
| | +--rw tls-versions
| | | ...
| | +--rw cipher-suites
| | ...
| +--rw keepalives {tls-client-keepalives}?
| +--rw peer-allowed-to-send? empty
| +--rw test-peer-aliveness!
| ...
+--rw filter
| +--rw facility-list* [facility severity]
| +--rw facility union
| +--rw severity union
| +--rw advanced-compare {select-adv-compare}?
| +--rw compare? enumeration
| +--rw action? identityref
+--rw pattern-match? string {select-match}?
+--rw structured-data? boolean {structured-data}?
+--rw facility-override? identityref
+--rw source-interface? if:interface-ref
| {remote-source-interface}?
+--rw signing! {signed-messages}?
+--rw cert-signers
+--rw cert-signer* [name]
| +--rw name string
| +--rw cert
| | +--rw public-key-format?
| | | identityref
| | +--rw public-key? binary
| | +--rw private-key-format?
| | | identityref
| | +--rw (private-key-type)
| | | +--:(cleartext-private-key)
| | | | {cleartext-private-keys}?
| | | | ...
| | | +--:(hidden-private-key)
| | | | {hidden-private-keys}?
| | | | ...
| | | +--:(encrypted-private-key)
| | | {encrypted-private-keys}?
| | | ...
| | +--rw cert-data?
| | | end-entity-cert-cms
| | +---n certificate-expiration
| | | {certificate-expiration-notification}
? {certificate-expiration-notification}?
| | | +-- expiration-date
| | | yang:date-and-time
| | +---x generate-csr {csr-generation}?
| | +---w input
| | | ...
| | +--ro output
| | ...
| +--rw hash-algorithm? enumeration
+--rw cert-initial-repeat? uint32
+--rw cert-resend-delay? uint32
+--rw cert-resend-count? uint32
+--rw sig-max-delay? uint32
+--rw sig-number-resends? uint32
+--rw sig-resend-delay? uint32
+--rw sig-resend-count? uint32
Figure 1: 2: Tree Diagram for Syslog Model
6.
5. Syslog YANG Module
6.1.
5.1. The ietf-syslog Module
This module imports typedefs from [RFC6991], [RFC8343], groupings
from [I-D.ietf-netconf-crypto-types], [RFC9640], and
[I-D.ietf-netconf-tls-client-server], and it [RFC9645]. It references [RFC5424], [RFC5425],
[RFC5426], [RFC5848], [RFC8089], [RFC8174], and [Std-1003.1-2008].
<CODE BEGINS> file "ietf-syslog@2024-09-18.yang" "ietf-syslog@2025-03-03.yang"
module ietf-syslog {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-syslog";
prefix syslog;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-interfaces {
prefix if;
reference
"RFC 8343: A YANG Data Model for Interface Management";
}
import ietf-tls-client {
prefix tlsc;
reference
"I-D.ietf-netconf-tls-client-server:
"RFC 9645: YANG Groupings for TLS Clients and TLS Servers";
}
import ietf-crypto-types {
prefix ct;
reference
"I-D.ietf-netconf-crypto-types:
"RFC 9640: YANG Data Types and Groupings for Cryptography";
}
organization
"IETF NETMOD (Network Modeling) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
Editor: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Joe Clarke
<mailto:jclarke@cisco.com>
Editor: Kiran Agrahara Sreenivasa
<mailto:kirankoushik.agraharasreenivasa@verizonwireless.com>
Editor: Clyde Wildes
<mailto:clyde@clydewildes.com>";
description
"This module contains a collection of YANG definitions
for syslog configuration.
Copyright (c) 2024 2025 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 Revised BSD License
set forth in Section 4.c of the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC zzzz
(https://www.rfc-editor.org/info/rfczzzz); 9742
(https://www.rfc-editor.org/info/rfc9742);
see the RFC itself for full legal notices.
The key words '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 (RFC 2119)
(RFC 8174) when, and only when, they appear in all capitals,
as shown here.";
revision 2024-09-18 2025-03-03 {
description
"Initial Revision";
reference
"RFC zzzz: 9742: Syslog YANG Model"; Module";
}
feature console-action {
description
"This feature indicates that the local console action is
supported.";
}
feature file-action {
description
"This feature indicates that the local file action is
supported.";
}
feature file-limit-size {
description
"This feature indicates that file logging resources
are managed using size and number limits.";
}
feature file-limit-duration {
description
"This feature indicates that file logging resources
are managed using time based limits.";
}
feature remote-action {
description
"This feature indicates that the remote server action is
supported.";
}
feature remote-source-interface {
description
"This feature indicates that source-interface is supported
supported
for the remote-action.";
}
feature select-adv-compare {
description
"This feature represents the ability to select messages
using the additional comparison operators when comparing
the syslog message severity.";
}
feature select-match {
description
"This feature represents the ability to select messages
based on a Posix 1003.2 regular expression pattern
match.";
}
feature structured-data {
description
"This feature represents the ability to log messages
in structured-data format.";
reference
"RFC 5424: The Syslog Protocol";
}
feature signed-messages {
description
"This feature represents the ability to configure signed
syslog messages.";
reference
"RFC 5848: Signed Syslog Messages";
}
typedef syslog-severity {
type enumeration {
enum emergency {
value 0;
description
"The severity level 'Emergency' indicating indicates that the
system is unusable.";
}
enum alert {
value 1;
description
"The severity level 'Alert' indicating indicates that an
action must be taken immediately.";
}
enum critical {
value 2;
description
"The severity level 'Critical' indicating indicates a
critical condition.";
}
enum error {
value 3;
description
"The severity level 'Error' indicating indicates an error
condition.";
}
enum warning {
value 4;
description
"The severity level 'Warning' indicating indicates a warning
condition.";
}
enum notice {
value 5;
description
"The severity level 'Notice' indicating indicates a normal
but significant condition.";
}
enum info {
value 6;
description
"The severity level 'Info' indicating indicates an
informational message.";
}
enum debug {
value 7;
description
"The severity level 'Debug' indicating indicates a
debug-level message.";
}
}
description
"The definitions for Syslog message severity.
Note that a lower value is a higher severity. Comparisons
of equal-or-higher severity mean equal or lower equal-or-lower numeric
value";
reference
"RFC 5424: The Syslog Protocol";
}
identity syslog-facility {
description
"This identity is used as a base for all syslog
facilities.";
reference
"RFC 5424: The Syslog Protocol";
}
identity kern {
base syslog-facility;
description
"The facility for kernel messages (0).";
reference
"RFC 5424: The Syslog Protocol";
}
identity user {
base syslog-facility;
description
"The facility for user-level messages (1).";
reference
"RFC 5424: The Syslog Protocol";
}
identity mail {
base syslog-facility;
description
"The facility for the mail system (2).";
reference
"RFC 5424: The Syslog Protocol";
}
identity daemon {
base syslog-facility;
description
"The facility for the system daemons (3).";
reference
"RFC 5424: The Syslog Protocol";
}
identity auth {
base syslog-facility;
description
"The facility for security/authorization messages (4).";
reference
"RFC 5424: The Syslog Protocol";
}
identity syslog {
base syslog-facility;
description
"The facility for messages generated internally by a syslogd
facility (5).";
reference
"RFC 5424: The Syslog Protocol";
}
identity lpr {
base syslog-facility;
description
"The facility for the line printer subsystem (6).";
reference
"RFC 5424: The Syslog Protocol";
}
identity news {
base syslog-facility;
description
"The facility for the network news subsystem (7).";
reference
"RFC 5424: The Syslog Protocol";
}
identity uucp {
base syslog-facility;
description
"The facility for the UUCP Unix-to-Unix Copy (UUCP) subsystem (8).";
reference
"RFC 5424: The Syslog Protocol";
}
identity cron {
base syslog-facility;
description
"The facility for the clock daemon (9).";
reference
"RFC 5424: The Syslog Protocol";
}
identity authpriv {
base syslog-facility;
description
"The facility for privileged security/authorization
messages (10).";
reference
"RFC 5424: The Syslog Protocol";
}
identity ftp {
base syslog-facility;
description
"The facility for the FTP daemon (11).";
reference
"RFC 5424: The Syslog Protocol";
}
identity ntp {
base syslog-facility;
description
"The facility for the NTP subsystem (12).";
reference
"RFC 5424: The Syslog Protocol";
}
identity audit {
base syslog-facility;
description
"The facility for log audit messages (13).";
reference
"RFC 5424: The Syslog Protocol";
}
identity console {
base syslog-facility;
description
"The facility for log alert messages (14).";
reference
"RFC 5424: The Syslog Protocol";
}
identity cron2 {
base syslog-facility;
description
"The facility for the second clock daemon (15).";
reference
"RFC 5424: The Syslog Protocol";
}
identity local0 {
base syslog-facility;
description
"The facility for local use 0 messages (16).";
reference
"RFC 5424: The Syslog Protocol";
}
identity local1 {
base syslog-facility;
description
"The facility for local use 1 messages (17).";
reference
"RFC 5424: The Syslog Protocol";
}
identity local2 {
base syslog-facility;
description
"The facility for local use 2 messages (18).";
reference
"RFC 5424: The Syslog Protocol";
}
identity local3 {
base syslog-facility;
description
"The facility for local use 3 messages (19).";
reference
"RFC 5424: The Syslog Protocol";
}
identity local4 {
base syslog-facility;
description
"The facility for local use 4 messages (20).";
reference
"RFC 5424: The Syslog Protocol";
}
identity local5 {
base syslog-facility;
description
"The facility for local use 5 messages (21).";
reference
"RFC 5424: The Syslog Protocol";
}
identity local6 {
base syslog-facility;
description
"The facility for local use 6 messages (22).";
reference
"RFC 5424: The Syslog Protocol";
}
identity local7 {
base syslog-facility;
description
"The facility for local use 7 messages (23).";
reference
"RFC 5424: The Syslog Protocol";
}
identity action {
description
"Base identity for action for how a message will be
handled.";
}
identity log {
base action;
description
"This identity specifies that if the compare operation is
true
true, the message will be logged.";
}
identity block {
base action;
description
"This identity specifies that if the compare operation is
true
true, the message will not be logged.";
}
identity stop {
base action;
description
"This identity specifies that if the compare operation is
true
true, the message will not be logged and no further
processing will occur for it.";
}
grouping severity-filter {
description
"This grouping defines the processing used to select
log messages by comparing syslog message severity using
the following processing rules:
- if 'none', do not match.
- if 'all', match.
- else else, compare message severity with the specified
severity according to the default compare rule (all
messages of the specified severity and greater match)
or if the select-adv-compare feature is present, use
the advance-compare rule.";
leaf severity {
type union {
type syslog-severity;
type enumeration {
enum none {
value 2147483647;
description
"This enum describes the case where no
severities are selected.";
}
enum all {
value -2147483648;
description
"This enum describes the case where all
severities are selected.";
}
}
}
mandatory true;
description
"This leaf specifies the syslog message severity.";
}
container advanced-compare {
when "../severity != \"all\" and
../severity != \"none\"" {
description
"The advanced compare container is not applicable
for severity 'all' or severity 'none'";
}
if-feature "select-adv-compare";
leaf compare {
type enumeration {
enum equals {
description
"This enum specifies that the severity
comparison operation will be equals.";
}
enum equals-or-higher {
description
"This enum specifies that the severity
comparison operation will be equals or
higher.";
}
}
default "equals-or-higher";
description
"The compare can be used to specify the comparison
operator that should be used to compare the syslog
message severity with the specified severity.";
}
leaf action {
type identityref {
base "action"; action;
}
default "log";
description
"The action can be used to specify how the message
should be handled. This may include logging the
message, not logging the message (i.e., blocking
it), or stopping further processing.";
}
description
"This container describes additional severity compare
operations that can be used in place of the default
severity comparison. The compare leaf specifies the
type of the compare that is done and the action leaf
specifies the intended result.
Example: compare->equals and action->block means
messages that have a severity that are equal to the
specified severity will not be logged.";
}
}
grouping selector {
description
"This grouping defines a syslog selector selector, which is used to
select log messages for the log-actions (console, file,
remote, etc.). Choose one or both of the following:
facility [<facility> <severity>...]
pattern-match regular-expression-match-string
If both facility and pattern-match are specified, both
must match in order for a log message to be selected.";
container filter {
description
"This container describes the syslog filter
parameters.";
list facility-list {
key "facility severity";
ordered-by user;
description
"This list describes a collection of syslog
facilities and severities.";
leaf facility {
type union {
type identityref {
base syslog-facility;
}
type enumeration {
enum all {
description
"This enum describes the case where
all facilities are requested.";
}
}
}
description
"The leaf uniquely identifies a syslog
facility.";
}
uses severity-filter;
}
}
leaf pattern-match {
if-feature "select-match";
type string;
description
"This leaf describes a Posix 1003.2 regular expression
string that can be used to select a syslog message for
logging. The match is performed on the SYSLOG-MSG
field.";
reference
"RFC 5424: The Syslog Protocol
Std-1003.1-2008 Regular Expressions";
}
}
grouping structured-data {
description
"This grouping defines the syslog structured data option option,
which is used to select the format used to write log
messages.";
leaf structured-data {
if-feature "structured-data";
type boolean;
default "false";
description
"This leaf describes how log messages are written.
If true, messages will be written with one or more
STRUCTURED-DATA elements; if false, messages will be
written with STRUCTURED-DATA = NILVALUE.";
reference
"RFC 5424: The Syslog Protocol";
}
}
container syslog {
presence "Enables logging.";
description
"This container describes the configuration parameters for
syslog.";
container actions {
description
"This container describes the log-action parameters
for syslog.";
container console {
if-feature "console-action";
presence "Enables logging to the console";
description
"This container describes the configuration
parameters for console logging.";
uses selector;
}
container file {
if-feature "file-action";
description
"This container describes the configuration
parameters for file logging. If file-archive
limits are not supplied, it is assumed that
the local implementation defined limits will
be used.";
list log-file {
key "name";
description
"This list describes a collection of local
logging files.";
leaf name {
type inet:uri {
pattern 'file:.*';
}
description
"This leaf specifies the name of the log
file
file, which MUST use the uri scheme
file:.";
reference
"RFC 8089: The file URI Scheme";
}
uses selector;
uses structured-data;
container file-rotation {
description
"This container describes the configuration
parameters for log file rotation.";
leaf number-of-files {
if-feature "file-limit-size";
type uint32;
default "1";
description
"This leaf specifies the maximum number
of log files retained. Specify 1 for
implementations that only support one
log file.";
}
leaf max-file-size {
if-feature "file-limit-size";
type uint32;
units "megabytes";
description
"This leaf specifies the maximum log
file size.";
}
leaf rollover {
if-feature "file-limit-duration";
type uint32;
units "minutes";
description
"This leaf specifies the length of time
that log events should be written to a
specific log file. Log events that
arrive after the rollover period cause
the current log file to be closed and
a new log file to be opened.";
}
leaf retention {
if-feature "file-limit-duration";
type uint32;
units "minutes";
description
"This leaf specifies the length of time
that completed/closed log event files
should be stored in the file system
before they are removed.";
}
}
}
}
container remote {
if-feature "remote-action";
description
"This container describes the configuration
parameters for forwarding syslog messages
to remote relays or collectors.";
list destination {
key "name";
description
"This list describes a collection of remote logging
destinations.";
leaf name {
type string;
description
"An arbitrary name for the endpoint to connect to.";
}
choice transport {
mandatory true;
description
"This choice describes the transport option.";
case udp {
container udp {
description
"This container describes the UDP transport
options.";
reference
"RFC 5426: Transmission of Syslog Messages over
UDP";
list udp {
key "address";
description
"List of all UDP sessions.";
leaf address {
type inet:host;
description
"The leaf uniquely specifies the address of the
remote host. One of the following must be
specified:
- an ipv4 address,
- an ipv6 address, or a
- host name.";
}
leaf port {
type inet:port-number;
default "514";
description
"This leaf specifies the port number used to
deliver messages to the remote server.";
}
}
}
}
case tls {
container tls {
description
"This container describes the TLS transport
options.";
reference
"RFC 5425: Transport Layer Security (TLS) Transport
Mapping for Syslog ";
list tls {
key "address";
description
"List of all TLS based TLS-based sessions.";
leaf address {
type inet:host;
description
"The leaf uniquely specifies the address of the
remote host. One of the following must be
specified: an ipv4 address, an ipv6 address,
or a host name.";
}
leaf port {
type inet:port-number;
default "6514";
description
"TCP port 6514 has been allocated as the
default port for syslog over TLS.";
}
uses tlsc:tls-client-grouping;
}
}
}
}
uses selector;
uses structured-data;
leaf facility-override {
type identityref {
base syslog-facility;
}
description
"If specified, this leaf specifies the facility used
to override the facility in messages delivered to the
remote server.";
}
leaf source-interface {
if-feature "remote-source-interface";
type if:interface-ref;
description
"This leaf sets the source interface to be used to
send messages to the remote syslog server. If not set,
messages can be sent on any interface.";
}
container signing {
if-feature "signed-messages";
presence "If present, syslog-signing options is
activated.";
description
"This container describes the configuration
parameters for signed syslog messages.";
reference
"RFC 5848: Signed Syslog Messages";
container cert-signers {
description
"This container describes the signing certificate
configuration for Signature Group 0 0, which covers
the case for administrators who want all Signature
Blocks to be sent to a single destination.";
list cert-signer {
key "name";
description
"This list describes a collection of syslog message
signers.";
leaf name {
type string;
description
"This leaf specifies the name of the syslog
message signer.";
}
container cert {
uses ct:asymmetric-key-pair-with-cert-grouping;
description
"This is the certificate that is periodically
sent to the remote receiver. The certificate is
inherently associated with its private
and public keys.";
}
leaf hash-algorithm {
type enumeration {
enum SHA1 {
value 1;
description
"This enum describes the SHA1 algorithm.";
}
enum SHA256 {
value 2;
description
"This enum describes the SHA256 algorithm.";
}
}
description
"This leaf describes the syslog signer hash
algorithm used.";
}
}
leaf cert-initial-repeat {
type uint32;
default "3";
description
"This leaf specifies the number of times each
Certificate Block should be sent before the first
message is sent.";
}
leaf cert-resend-delay {
type uint32;
units "seconds";
default "3600";
description
"This leaf specifies the maximum time delay in
seconds until resending the Certificate Block.";
}
leaf cert-resend-count {
type uint32;
default "0";
description
"This leaf specifies the maximum number of other
syslog messages to send until resending the
Certificate Block.";
}
leaf sig-max-delay {
type uint32;
units "seconds";
default "60";
description
"This leaf specifies when to generate a new
Signature Block. If this many seconds have elapsed
since the message with the first message number
of the Signature Block was sent, a new Signature
Block should be generated.";
}
leaf sig-number-resends {
type uint32;
default "0";
description
"This leaf specifies the number of times a
Signature Block is resent. (It is recommended to
select a value of greater than 0 in particular
when the UDP transport as in RFC 5426 is used.)."; used.)";
}
leaf sig-resend-delay {
type uint32;
units "seconds";
default "5";
description
"This leaf specifies when to send the next
Signature Block transmission based on time. If
this many seconds have elapsed since the previous
sending of this Signature Block, resend it.";
}
leaf sig-resend-count {
type uint32;
default "0";
description
"This leaf specifies when to send the next
Signature Block transmission based on a count.
If this many other syslog messages have been sent
since the previous sending of this Signature
Block, resend it. A value of 0 means that you
don't resend based on the number of messages.";
}
}
}
}
}
}
}
}
<CODE ENDS>
Figure 2: Sylog 3: Syslog YANG Model
7. Module
6. Usage Examples
7.1.
6.1. Syslog Configuration for Severity Critical
[note: '\' line wrapping for formatting only]
<!--
Enable console logging of syslogs of severity critical
-->
<?xml version="1.0" encoding="UTF-8"?>
<syslog xmlns="urn:ietf:params:xml:ns:yang:ietf-syslog">
<actions>
<console>
<filter>
<facility-list>
<facility>all</facility>
<severity>critical</severity>
</facility-list>
</filter>
</console>
</actions>
</syslog>
Figure 3: 4: Syslog Configuration for Severity Critical
7.2.
6.2. Remote Syslog Configuration
[note: '\' line wrapping for formatting only]
<!--
Enable remote logging of syslogs to udp destination
foo.example.com for facility auth, severity error
-->
<?xml version="1.0" encoding="UTF-8"?>
<syslog xmlns="urn:ietf:params:xml:ns:yang:ietf-syslog">
<actions>
<remote>
<destination>
<name>remote1</name>
<udp>
<udp>
<address>foo.example.com</address>
</udp>
</udp>
<filter>
<facility-list>
<facility>auth</facility>
<severity>error</severity>
</facility-list>
</filter>
</destination>
</remote>
</actions>
</syslog>
Figure 4: 5: Remote Syslog Configuration
8. Acknowledgements
The authors wish to thank the following who commented on this
proposal:
Andy Bierman, Martin Bjorklund, Alex Campbell, Alex Clemm, Francis
Dupont, Jim Gibson, Jeffrey Haas, Bob Harold, John Heasley, Giles
Heron, Lisa Huang, Mahesh Jethanandani, Warren Kumari, Jeffrey K
Lange, Jan Lindblad, Chris Lonvick, Alexey Melnikov, Kathleen
Moriarty, Tom Petch, Adam Roach, Juergen Schoenwaelder, Phil Shafer,
Yaron Sheffer, Jason Sterne, Peter Van Horne, Kent Watsen, Bert
Wijnen, Dale R Worley, and Aleksandr Zhdankin.
9.
7. IANA Considerations
9.1.
7.1. The IETF XML Registry
This document registers one URI in the IETF "IETF XML registry [RFC3688] .
Following Registry", following
the format defined in [RFC3688] , the following registration is
requested: [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-syslog
Registrant Contact: The IESG.
XML: N/A, N/A; the requested URI is an XML namespace.
9.2.
7.2. The YANG Module Names Registry
This document registers one YANG module in the YANG "YANG Module Names Names"
registry [RFC8525] . Following [RFC8525], following the format in [RFC7950] , the
following registration is requested:
name: [RFC7950]:
Name: ietf-syslog
namespace:
Namespace: urn:ietf:params:xml:ns:yang:ietf-syslog
prefix:
Prefix: syslog
reference:
Reference: RFC zzzz
10. 9742
8. Security Considerations
This section is modeled after the template defined in Section 3.7.1
of [RFC8407].
The "ietf-syslog" YANG module specified in this document defines a schema for data model
that is designed to be accessed via YANG-based network management protocols such
as NETCONF [RFC6241] and or RESTCONF [RFC8040]. These
protocols have The lowest NETCONF layer
is the secure transport layer, and the mandatory-to-implement secure
transport layers (e.g., is Secure Shell (SSH) [RFC4252], TLS [RFC8446], and QUIC [RFC9000]) [RFC4252]. The lowest RESTCONF layer
is HTTPS, and the mandatory-to-implement mutual authentication. secure transport is TLS
[RFC8446].
The NETCONF access control model Network Configuration Access Control Model (NACM) [RFC8341]
provides the means to restrict access for particular NETCONF or
RESTCONF users to a preconfigured subset of all available NETCONF or
RESTCONF protocol operations and content.
This module imports groupings from ietf-crypto-types YANG module
defined in YANG Groupings for Crypto Types
[I-D.ietf-netconf-crypto-types]. [RFC9640]. Security
considerations described in that document apply to this module also.
There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., config true, which is the
default). These data nodes should be considered sensitive or
vulnerable in all network environments. Logging in particular is
used to assess the state of systems and can be used to indicate a
network compromise. If logging were to be disabled through malicious
means, attacks may not be readily detectable. Therefore Therefore, write
operations (e.g., edit-config) to these data nodes without proper
protection can have a negative effect on network operations and on
network security.
In addition addition, there are data nodes that require careful analysis and
review. These are the subtrees and data nodes and their sensitivity/
vulnerability:
facility-filter/pattern-match: When writing this node,
implementations MUST ensure that the regular expression pattern
match is not constructed to cause a regular expression denial
of denial-of-
service attack due to a pattern that causes the regular expression
implementation to work very slowly (exponentially related to input
size).
remote/destination/signing/cert-signer: When writing this subtree,
implementations MUST NOT specify a private key that is used for
any other purpose.
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:
remote/destination/transport: This subtree contains information
about other hosts in the network, the services available on those
hosts, and the TLS transport certificate properties if TLS is
selected as the transport protocol. Knowing that a service like
syslog (udp/514) is enabled on the host, host will allow a malicious
user to spam the host on that port.
remote/destination/signing: This subtree contains information about
the syslog message signing properties properties, including signing
certificate information.
There are no RPC operations defined in this YANG module.
11.
9. References
11.1.
9.1. Normative References
[I-D.ietf-netconf-crypto-types]
Watsen, K., "YANG Data Types and Groupings for
Cryptography", Work in Progress, Internet-Draft, draft-
ietf-netconf-crypto-types-34, 16 March 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
crypto-types-34>.
[I-D.ietf-netconf-tls-client-server]
Watsen, K., "YANG Groupings for TLS Clients and TLS
Servers", Work in Progress, Internet-Draft, draft-ietf-
netconf-tls-client-server-41, 16 March 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
tls-client-server-41>.
[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>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC4252] Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252,
January 2006, <https://www.rfc-editor.org/info/rfc4252>.
[RFC5424] Gerhards, R., "The Syslog Protocol", RFC 5424,
DOI 10.17487/RFC5424, March 2009,
<https://www.rfc-editor.org/info/rfc5424>.
[RFC5425] Miao, F., Ed., Ma, Y., Ed., and J. Salowey, Ed.,
"Transport Layer Security (TLS) Transport Mapping for
Syslog", RFC 5425, DOI 10.17487/RFC5425, March 2009,
<https://www.rfc-editor.org/info/rfc5425>.
[RFC5426] Okmianski, A., "Transmission of Syslog Messages over UDP",
RFC 5426, DOI 10.17487/RFC5426, March 2009,
<https://www.rfc-editor.org/info/rfc5426>.
[RFC5848] Kelsey, J., Callas, J., and A. Clemm, "Signed Syslog
Messages", RFC 5848, DOI 10.17487/RFC5848, May 2010,
<https://www.rfc-editor.org/info/rfc5848>.
[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>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[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>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8089] Kerwin, M., "The "file" URI Scheme", RFC 8089,
DOI 10.17487/RFC8089, February 2017,
<https://www.rfc-editor.org/info/rfc8089>.
[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>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
[RFC8343] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
<https://www.rfc-editor.org/info/rfc8343>.
[RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of
Documents Containing YANG Data Models", BCP 216, RFC 8407,
DOI 10.17487/RFC8407, October 2018,
<https://www.rfc-editor.org/info/rfc8407>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC8525] Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K.,
and R. Wilton, "YANG Library", RFC 8525,
DOI 10.17487/RFC8525, March 2019,
<https://www.rfc-editor.org/info/rfc8525>.
[RFC9000] Iyengar, J., Ed.
[RFC9640] Watsen, K., "YANG Data Types and M. Thomson, Ed., "QUIC: A UDP-Based
Multiplexed Groupings for
Cryptography", RFC 9640, DOI 10.17487/RFC9640, October
2024, <https://www.rfc-editor.org/info/rfc9640>.
[RFC9645] Watsen, K., "YANG Groupings for TLS Clients and Secure Transport", TLS
Servers", RFC 9000, 9645, DOI 10.17487/RFC9000, May 2021,
<https://www.rfc-editor.org/info/rfc9000>. 10.17487/RFC9645, October 2024,
<https://www.rfc-editor.org/info/rfc9645>.
[Std-1003.1-2008]
The Open Group, I. A. T. O., ""Chapter 9: Regular Expressions". Expressions" The Open
Group Base Specifications Issue 6, IEEE Std 1003.1-2008,
2016 Edition.", Edition", September 2016,
<http://pubs.opengroup.org/onlinepubs/9699919799/>.
11.2.
<https://pubs.opengroup.org/
onlinepubs/9699919799.2016edition/>.
9.2. Informative References
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
Appendix A. Tree Diagrams
A.1. Complete Tree Diagram
[note: '\' line wrapping for formatting only]
module: ietf-syslog
+--rw syslog!
+--rw actions
+--rw console! {console-action}?
| +--rw filter
| | +--rw facility-list* [facility severity]
| | +--rw facility union
| | +--rw severity union
| | +--rw advanced-compare {select-adv-compare}?
| | +--rw compare? enumeration
| | +--rw action? identityref
| +--rw pattern-match? string {select-match}?
+--rw file {file-action}?
| +--rw log-file* [name]
| +--rw name inet:uri
| +--rw filter
| | +--rw facility-list* [facility severity]
| | +--rw facility union
| | +--rw severity union
| | +--rw advanced-compare {select-adv-compare}?
| | +--rw compare? enumeration
| | +--rw action? identityref
| +--rw pattern-match? string {select-match}?
| +--rw structured-data? boolean {structured-data}?
| +--rw file-rotation
| +--rw number-of-files? uint32 {file-limit-size}?
| +--rw max-file-size? uint32 {file-limit-size}?
| +--rw rollover? uint32
| | {file-limit-duration}?
| +--rw retention? uint32
| {file-limit-duration}?
+--rw remote {remote-action}?
+--rw destination* [name]
+--rw name string
+--rw (transport)
| +--:(udp)
| | +--rw udp
| | +--rw udp* [address]
| | +--rw address inet:host
| | +--rw port? inet:port-number
| +--:(tls)
| +--rw tls
| +--rw tls* [address]
| +--rw address inet:host
| +--rw port?
| | inet:port-number
| +--rw client-identity!
| | +--rw (auth-type)
| | +--:(certificate)
| | | {client-ident-x509-cert}?
| | | +--rw certificate
| | | +--rw (inline-or-keystore)
| | | +--:(inline)
| | | | {inline-definition\
s-s
upported}?
s-supported}?
| | | | +--rw inline-definition
| | | | +--rw public-key-form\
at?
| | | | | identityref
| | | | +--rw public-key?
| | | | | binary
| | | | +--rw private-key-for\
mat
?
mat?
| | | | | identityref
| | | | +--rw (private-key-ty\
pe)
| | | | | +--:(cleartext-pri\
vat
e-key)
vate-key)
| | | | | | {cleartex\
t-p
rivate-keys}?
t-private-keys}?
| | | | | | +--rw cleartext\
-pr
ivate-key?
-private-key?
| | | | | | binary
| | | | | +--:(hidden-privat\
e-k
ey)
e-key)
| | | | | | {hidden-p\
riv
ate-keys}?
rivate-keys}?
| | | | | | +--rw hidden-pr\
iva
te-key?
ivate-key?
| | | | | | empty
| | | | | +--:(encrypted-pri\
vat
e-key)
vate-key)
| | | | | {encrypte\
d-p
rivate-keys}?
d-private-keys}?
| | | | | +--rw encrypted\
-pr
ivate-key
-private-key
| | | | | +--rw encryp\
ted
-by
ted-by
| | | | | +--rw encryp\
ted
-value-format
ted-value-format
| | | | | | iden\
tit
yref
tityref
| | | | | +--rw encryp\
ted
-value
ted-value
| | | | | bina\
ry
| | | | +--rw cert-data?
| | | | | end-entity-ce\
rt-
cms
rt-cms
| | | | +---n certificate-exp\
ira
tion
iration
| | | | | {certificate-\
exp
iration-notification}?
expiration-notification}?
| | | | | +-- expiration-dat\
e
| | | | | yang:date-\
and
-time
and-time
| | | | +---x generate-csr
| | | | {csr-generati\
on}
?
on}?
| | | | +---w input
| | | | | +---w csr-forma\
t
| | | | | | identit\
yre
f
yref
| | | | | +---w csr-info
| | | | | csr-inf\
o
| | | | +--ro output
| | | | +--ro (csr-type\
)
| | | | +--:(p10-csr\
)
| | | | +--ro p10\
-cs
r?
-csr?
| | | | p\
10-
csr
10-csr
| | | +--:(central-keystore)
| | | {central-keystore-\
sup
ported,asymmetric-keys}?
supported,asymmetric-keys}?
| | | +--rw central-keystore-r\
efe
rence
eference
| | | +--rw asymmetric-key?\
| | | | ks:central-as\
ymm
etric-key-ref
ymmetric-key-ref
| | | | {central-keys\
tor
e-supported,asymmetric-keys}?
tore-supported,asymmetric-keys}?
| | | +--rw certificate?
| | | leafref
| | +--:(raw-public-key)
| | | {client-ident-raw-public-ke\
y}?
| | | +--rw raw-private-key
| | | +--rw (inline-or-keystore)
| | | +--:(inline)
| | | | {inline-definition\
s-s
upported}?
s-supported}?
| | | | +--rw inline-definition
| | | | +--rw public-key-form\
at?
| | | | | identityref
| | | | +--rw public-key?
| | | | | binary
| | | | +--rw private-key-for\
mat
?
mat?
| | | | | identityref
| | | | +--rw (private-key-ty\
pe)
| | | | +--:(cleartext-pri\
vat
e-key)
vate-key)
| | | | | {cleartex\
t-p
rivate-keys}?
t-private-keys}?
| | | | | +--rw cleartext\
-pr
ivate-key?
-private-key?
| | | | | binary
| | | | +--:(hidden-privat\
e-k
ey)
e-key)
| | | | | {hidden-p\
riv
ate-keys}?
rivate-keys}?
| | | | | +--rw hidden-pr\
iva
te-key?
ivate-key?
| | | | | empty
| | | | +--:(encrypted-pri\
vat
e-key)
vate-key)
| | | | {encrypte\
d-p
rivate-keys}?
d-private-keys}?
| | | | +--rw encrypted\
-pr
ivate-key
-private-key
| | | | +--rw encryp\
ted
-by
ted-by
| | | | +--rw encryp\
ted
-value-format
ted-value-format
| | | | | iden\
tit
yref
tityref
| | | | +--rw encryp\
ted
-value
ted-value
| | | | bina\
ry
| | | +--:(central-keystore)
| | | {central-keystore-\
sup
ported,asymmetric-keys}?
supported,asymmetric-keys}?
| | | +--rw central-keystore-r\
efe
rence?
eference?
| | | ks:central-asymm\
etr
ic-key-ref
etric-key-ref
| | +--:(tls12-psk)
| | | {client-ident-tls12-psk}?
| | | +--rw tls12-psk
| | | +--rw (inline-or-keystore)
| | | | +--:(inline)
| | | | | {inline-definition\
s-s
upported}?
s-supported}?
| | | | | +--rw inline-definition
| | | | | +--rw key-format?
| | | | | | identityref
| | | | | +--rw (key-type)
| | | | | +--:(cleartext-sym\
met
ric-key)
metric-key)
| | | | | | +--rw cleartext\
-sy
mmetric-key?
-symmetric-key?
| | | | | | binary
| | | | | | {cleart\
ext
-symmetric-keys}?
ext-symmetric-keys}?
| | | | | +--:(hidden-symmet\
ric
-key)
ric-key)
| | | | | | {hidden-s\
ymm
etric-keys}?
ymmetric-keys}?
| | | | | | +--rw hidden-sy\
mme
tric-key?
mmetric-key?
| | | | | | empty
| | | | | +--:(encrypted-sym\
met
ric-key)
metric-key)
| | | | | {encrypte\
d-s
ymmetric-keys}?
d-symmetric-keys}?
| | | | | +--rw encrypted\
-sy
mmetric-key
-symmetric-key
| | | | | +--rw encryp\
ted
-by
ted-by
| | | | | +--rw encryp\
ted
-value-format
ted-value-format
| | | | | | iden\
tit
yref
tityref
| | | | | +--rw encryp\
ted
-value
ted-value
| | | | | bina\
ry
| | | | +--:(central-keystore)
| | | | {central-keystore-\
sup
ported,symmetric-keys}?
supported,symmetric-keys}?
| | | | +--rw central-keystore-r\
efe
rence?
eference?
| | | | ks:central-symme\
tri
c-key-ref
tric-key-ref
| | | +--rw id?
| | | string
| | +--:(tls13-epsk)
| | {client-ident-tls13-epsk}?
| | +--rw tls13-epsk
| | +--rw (inline-or-keystore)
| | | +--:(inline)
| | | | {inline-definition\
s-s
upported}?
s-supported}?
| | | | +--rw inline-definition
| | | | +--rw key-format?
| | | | | identityref
| | | | +--rw (key-type)
| | | | +--:(cleartext-sym\
met
ric-key)
metric-key)
| | | | | +--rw cleartext\
-sy
mmetric-key?
-symmetric-key?
| | | | | binary
| | | | | {cleart\
ext
-symmetric-keys}?
ext-symmetric-keys}?
| | | | +--:(hidden-symmet\
ric
-key)
ric-key)
| | | | | {hidden-s\
ymm
etric-keys}?
ymmetric-keys}?
| | | | | +--rw hidden-sy\
mme
tric-key?
mmetric-key?
| | | | | empty
| | | | +--:(encrypted-sym\
met
ric-key)
metric-key)
| | | | {encrypte\
d-s
ymmetric-keys}?
d-symmetric-keys}?
| | | | +--rw encrypted\
-sy
mmetric-key
-symmetric-key
| | | | +--rw encryp\
ted
-by
ted-by
| | | | +--rw encryp\
ted
-value-format
ted-value-format
| | | | | iden\
tit
yref
tityref
| | | | +--rw encryp\
ted
-value
ted-value
| | | | bina\
ry
| | | +--:(central-keystore)
| | | {central-keystore-\
sup
ported,symmetric-keys}?
supported,symmetric-keys}?
| | | +--rw central-keystore-r\
efe
rence?
eference?
| | | ks:central-symme\
tri
c-key-ref
tric-key-ref
| | +--rw external-identity
| | | string
| | +--rw hash?
| | | tlscmn:epsk-supported-\
has
h
hash
| | +--rw context?
| | | string
| | +--rw target-protocol?
| | | uint16
| | +--rw target-kdf?
| | uint16
| +--rw server-authentication
| | +--rw ca-certs! {server-auth-x509-cert}\
?
| | | +--rw (inline-or-truststore)
| | | +--:(inline)
| | | | {inline-definitions-supp\
ort
ed}?
orted}?
| | | | +--rw inline-definition
| | | | +--rw certificate* [name]
| | | | +--rw name
| | | | | string
| | | | +--rw cert-data
| | | | | trust-anchor-cer\
t-c
ms
t-cms
| | | | +---n certificate-expira\
tio
n
tion
| | | | {certificate-exp\
ira
tion-notification}?
iration-notification}?
| | | | +-- expiration-date
| | | | yang:date-and\
-ti
me
-time
| | | +--:(central-truststore)
| | | {central-truststore-supp\
ort
ed,certificates}?
orted,certificates}?
| | | +--rw central-truststore-refer\
enc
e?
ence?
| | | ts:central-certificate\
-ba
g-ref
-bag-ref
| | +--rw ee-certs! {server-auth-x509-cert}\
?
| | | +--rw (inline-or-truststore)
| | | +--:(inline)
| | | | {inline-definitions-supp\
ort
ed}?
orted}?
| | | | +--rw inline-definition
| | | | +--rw certificate* [name]
| | | | +--rw name
| | | | | string
| | | | +--rw cert-data
| | | | | trust-anchor-cer\
t-c
ms
t-cms
| | | | +---n certificate-expira\
tio
n
tion
| | | | {certificate-exp\
ira
tion-notification}?
iration-notification}?
| | | | +-- expiration-date
| | | | yang:date-and\
-ti
me
-time
| | | +--:(central-truststore)
| | | {central-truststore-supp\
ort
ed,certificates}?
orted,certificates}?
| | | +--rw central-truststore-refer\
enc
e?
ence?
| | | ts:central-certificate\
-ba
g-ref
-bag-ref
| | +--rw raw-public-keys!
| | | {server-auth-raw-public-key}?
| | | +--rw (inline-or-truststore)
| | | +--:(inline)
| | | | {inline-definitions-supp\
ort
ed}?
orted}?
| | | | +--rw inline-definition
| | | | +--rw public-key* [name]
| | | | +--rw name
| | | | | string
| | | | +--rw public-key-format
| | | | | identityref
| | | | +--rw public-key
| | | | binary
| | | +--:(central-truststore)
| | | {central-truststore-supp\
ort
ed,public-keys}?
orted,public-keys}?
| | | +--rw central-truststore-refer\
enc
e?
ence?
| | | ts:central-public-key-\
bag
-ref
bag-ref
| | +--rw tls12-psks? empty
| | | {server-auth-tls12-psk}?
| | +--rw tls13-epsks? empty
| | {server-auth-tls13-epsk}?
| +--rw hello-params {tlscmn:hello-params}?
| | +--rw tls-versions
| | | +--rw min? identityref
| | | +--rw max? identityref
| | +--rw cipher-suites
| | +--rw cipher-suite*
| | tlscsa:tls-cipher-suite-algo\
rit
hm
rithm
| +--rw keepalives {tls-client-keepalives}?
| +--rw peer-allowed-to-send? empty
| +--rw test-peer-aliveness!
| +--rw max-wait? uint16
| +--rw max-attempts? uint8
+--rw filter
| +--rw facility-list* [facility severity]
| +--rw facility union
| +--rw severity union
| +--rw advanced-compare {select-adv-compare}?
| +--rw compare? enumeration
| +--rw action? identityref
+--rw pattern-match? string {select-match}?
+--rw structured-data? boolean {structured-data}?
+--rw facility-override? identityref
+--rw source-interface? if:interface-ref
| {remote-source-interface}?
+--rw signing! {signed-messages}?
+--rw cert-signers
+--rw cert-signer* [name]
| +--rw name string
| +--rw cert
| | +--rw public-key-format?
| | | identityref
| | +--rw public-key? binar\
y
| | +--rw private-key-format?
| | | identityref
| | +--rw (private-key-type)
| | | +--:(cleartext-private-key)
| | | | {cleartext-private-keys}?
| | | | +--rw cleartext-private-key? binar\
y
| | | +--:(hidden-private-key)
| | | | {hidden-private-keys}?
| | | | +--rw hidden-private-key? empty\
| | | +--:(encrypted-private-key)
| | | {encrypted-private-keys}?
| | | +--rw encrypted-private-key
| | | +--rw encrypted-by
| | | +--rw encrypted-value-format
| | | | identityref
| | | +--rw encrypted-value
| | | binary
| | +--rw cert-data?
| | | end-entity-cert-cms
| | +---n certificate-expiration
| | | {certificate-expiration-notificati\
on}
?
on}?
| | | +-- expiration-date
| | | yang:date-and-time
| | +---x generate-csr {csr-generation}?
| | +---w input
| | | +---w csr-format identityref
| | | +---w csr-info csr-info
| | +--ro output
| | +--ro (csr-type)
| | +--:(p10-csr)
| | +--ro p10-csr? p10-csr
| +--rw hash-algorithm? enumeration
+--rw cert-initial-repeat? uint32
+--rw cert-resend-delay? uint32
+--rw cert-resend-count? uint32
+--rw sig-max-delay? uint32
+--rw sig-number-resends? uint32
+--rw sig-resend-delay? uint32
+--rw sig-resend-count? uint32
Appendix B. Implementer Guidelines
B.1. Extending Facilities
Many vendors extend the list of facilities available for logging in
their implementation. Additional facilities may not work with the
syslog protocol as defined in [RFC5424] and hence [RFC5424]. Thus, such facilities apply
for local syslog-like logging functionality.
The following is an example that shows how additional facilities
could be added to the list of available facilities (in this example
two (two facilities
are added):
[note: '\' line wrapping for formatting only] added in this example):
module example-vendor-syslog-types {
namespace "http://example.com/ns/vendor-syslog-types";
prefix vendor-syslogtypes;
import ietf-syslog {
prefix syslog;
}
organization
"Example, Inc.";
contact
"Example, Inc.
Customer Service
E-mail:
Email: syslog-yang@example.com";
description
"This module contains a collection of vendor-specific YANG type
definitions for SYSLOG."; Syslog.";
revision 2024-03-19 2025-03-03 {
description
"Version 1.0";
reference
"Vendor SYSLOG Syslog Types: SYSLOG Syslog YANG Model"; Module";
}
identity vendor_specific_type_1 {
base syslog:syslog-facility;
description
"Adding vendor specific vendor-specific type 1 to syslog-facility";
}
identity vendor_specific_type_2 {
base syslog:syslog-facility;
description
"Adding vendor specific vendor-specific type 2 to syslog-facility";
}
}
B.2. Syslog Terminal Output
Terminal output with requirements more complex than the console
subtree currently provides, provides are expected to be supported via vendor
extensions rather than handled via the file subtree.
B.3. Syslog File Naming Convention
The syslog/file/log-file/file-rotation container contains
configuration parameters for syslog file rotation. This section
describes how these fields might be used by an implementer to name
syslog files in a rotation process. This information is offered as
an informative guide only.
When an active syslog file with a name specified by log-file/name, log-file/name
reaches log-file/max-file-size and/or syslog events arrive after the
period specified by log-file/rollover, the logging system can close
the file, can compress it, and can name the archive file <log-file/
name>.0.gz. The logging system can then open a new active syslog
file <log-file/name>.
When the new syslog file reaches either of the size limits referenced
above, <log-file/name>.0.gz can be renamed <log-file/name>.1.gz and
the new syslog file can be closed, compressed compressed, and renamed <log-file/
name>.0.gz. Each time that a new syslog file is closed, each of the
prior syslog archive files named <log-file/name>.<n>.gz can be
renamed to <log-file/name>.<n + 1>.gz.
Removal of archive log files could occur when either or both:
-
* log-file/number-of-files specified - the is specified. The logging system can
create up to log-file/number-of-files syslog archive files files, after which,
which the contents of the oldest archived file could be
overwritten.
-
* log-file/retention specified - the is specified. The logging system can remove
those syslog archive files whose file expiration time (file
creation time plus the specified log-file/retention time) is prior
to the current time.
Acknowledgements
The authors wish to thank the following who commented on this
proposal:
Andy Bierman, Martin Bjorklund, Alex Campbell, Alex Clemm, Francis
Dupont, Jim Gibson, Jeffrey Haas, Bob Harold, John Heasley, Giles
Heron, Lisa Huang, Mahesh Jethanandani, Warren Kumari, Jeffrey K
Lange, Jan Lindblad, Chris Lonvick, Alexey Melnikov, Kathleen
Moriarty, Tom Petch, Adam Roach, Juergen Schoenwaelder, Phil Shafer,
Yaron Sheffer, Jason Sterne, Peter Van Horne, Kent Watsen, Bert
Wijnen, Dale R Worley, and Aleksandr Zhdankin.
Authors' Addresses
Joe Clarke (editor)
Cisco
United States of America
Email: jclarke@cisco.com
Mahesh Jethanandani (editor)
Kloud Services
United States of America
Email: mjethanandani@gmail.com
Clyde Wildes (editor)
Cisco Systems Inc.
170 West Tasman Drive
San Jose, CA 95134
United States of America
Phone: +1 415 819-6111
Email: clyde@clydewildes.com
Kiran Koushik (editor)
Verizon Wireless
500 W Dove Rd.
Southlake, TX 76092
United States of America
Phone: +1 512 650-0210
Email: kirankoushik.agraharasreenivasa@verizonwireless.com