Network Working Group S. Chisholm Internet-Draft Nortel Intended status: Standards Track R. Gerhards Expires:May 6,November 27, 2009 Adiscon GmbHNovember 2, 2008May 26, 2009 Alarms in SYSLOGdraft-ietf-opsawg-syslog-alarm-01.txtdraft-ietf-opsawg-syslog-alarm-02.txt Status of this MemoBy submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or sheThis Internet-Draft isaware have been or will be disclosed, and any of which he or she becomes aware will be disclosed,submitted to IETF inaccordancefull conformance withSection 6the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents asInternet- Drafts.Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire onMay 6,November 27, 2009. Copyright Notice Copyright(C) The(c) 2009 IETF Trust(2008).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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract This document describes how to send alarm information in syslog. It includes the mapping of ITU perceived severities onto syslog messagefields.fields and a number of alarm-specific SD-PARAM definitions from X.733 and the IETF Alarm MIB. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 31.1. terminology . . . . . . . . . . . . . . . . . . . . . . . 32. Severity Mapping . . . . . . . . . . . . . . . . . . . . . . . 4 3. Alarm STRUCTURED-DATA Elements . . . . . . . . . . . . . . . . 5 3.1.alarmedResourceresource . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2. probableCause . . . . . . . . . . . . . . . . . . . . . . 5 3.3. perceivedSeverity . . . . . . . . . . . . . . . . . . . . 5 3.4. eventType . . . . . . . . . . . . . . . . . . . . . . . . 6 3.5. trendIndication . . . . . . . . . . . . . . . . . . . . . 6 3.6.resourceMappingresourceURI . . . . . . . . . . . . . . . . . . . . . . . 6 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . .7 5.9 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . .8 6.10 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .9 7.11 8. References . . . . . . . . . . . . . . . . . . . . . . . . . .10 7.1.12 8.1. Normative References . . . . . . . . . . . . . . . . . . .10 7.2.12 8.2. Informative References . . . . . . . . . . . . . . . . . .1012 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .1113 Intellectual Property and Copyright Statements . . . . . . . . . .1214 1. Introduction In addition to sending out alarm information asynchronously via protocols such as SNMP or Netconf, many implementations also log alarms via syslog. This memo defines a set of SD-PARAM to support logging and defines a mapping of syslog severity to the severity of the alarm.1.1.The Alarm MIB (RFC 3877) included mandatory alarm fields from X.733 as well as information from X.736. In additional, the Alarm MIB introduced its own alarm fields. This memo reuses terminology and fields from the Alarm MIB. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described inRFC2119[RFC2119]. Alarm related terminology is defined in [RFC3877]. 2. Severity Mapping The Alarm MIBRFC3877[RFC3877] defines ITU perceived severities which are useful to be able to relate to the syslog message fields, particularly in the case where alarms are being logged. This memo describes the representation of ITU perceived severities in appropriate syslog fields described in[Syslog].[RFC5424]. Syslog offers both a so-called SEVERITY as well as STRUCTURED-DATA. Due to constraints in syslog, there is no one-to-one mapping possible for SEVERITY. A STRUCTURED-DATA element is defined to allow inclusion of the unmodified ITU perceived severity. Syslog supports severity values different from ITU perceived severities. These are defined in section 6.2.1 of[Syslog].[RFC5424]. The mapping shown in table 1 below SHOULD be used to map ITU perceived severities to syslog severities. ITU Perceived Severity syslog SEVERITY (Name) Critical 1 (Alert) Major 2 (Critical) Minor 3 (Error) Warning 4 (Warning) Indeterminate 5 (Notice) Cleared 5 (Notice) Table 1. ITUPerceivedSeverity to syslog SEVERITY mapping. 3. Alarm STRUCTURED-DATA Elements STRUCTURED-DATA allows to include any structured information into a syslog message. The following are defined to support structuring alarm information. o Resource Under Alarm o Probable Cause o Event Type o Perceived Severity o Trend Indication o ResourceMappingURI Support of thealarm"alarm" SD-ID is optional, but once supported some of the SD-PARARMS are mandatory. 3.1.alarmedResourceresource If thealarm"alarm" SD-ID is supported, thealarmResource"resource" SD-PARAM MUST be supported. This item uniquely identifies the resource under alarm within the scope of a network element. 3.2. probableCause If thealarm"alarm" SD-ID is supported, theprobableCause"probableCause" SD-PARAM MUST be supported. This parameter is the mnemonic associated with the IANAItuProbableCause object defined within [RFC3877] and any subsequent extensions defined by IANA. For example, IANAItuProbableCause defines a transmission failure to a probable cause of 'transmissionError (10)'. The value of the parameter in this case would be 'transmissionError'" 3.3. perceivedSeverity If thealarm"alarm" SD-ID is supported, theperceivedSeverity"perceivedSeverity" SD-PARAM MUST be supported. Similar to the definition of perceived severity in [X.736] and [RFC3877], this object can take the following values: o cleared o indeterminate o critical o major o minor o warning See section 2 for the relationship between this severity and syslog severity. 3.4. eventType If thealarm"alarm" SD-ID is supported, theeventType"eventType" SD-PARAM SHOULD be supported. This parameter is the mnemonic associated with the IANAItuEventType object defined within [RFC3877] and any subsequent extensions defined by IANA. For example, IANAItuEventType defines a environmental alarm to a event type of 'environmentalAlarm (6)'. The value of the parameter in this case would be 'environmentalAlarm'" 3.5. trendIndication If thealarm"alarm" SD-ID is supported, thetrendIndication"trendIndication" SD-PARAM SHOULD be supported. Similar to the definition of perceived severity in [X.733] and [RFC3877], this object can take the following values: o moreSevere o noChange o lessSevere 3.6.resourceMappingresourceURI If thealarm"alarm" SD-ID is supported, theresourceMapping"resourceURI" SD-PARAM SHOULD be supported. This item uniquely identifies the resource underalarm withinalarm. The value of this field MUST conform to thescopeURI definition in [RFC1738] and its updates. In the case ofa network element. This mustan SNMP resource, the syntax in [RFC4088] MUST be used and "resourceURI" must point to the samevalueresource as alarmActiveResourceId [RFC3877] for thisalarm or follow similar semantics ifalarm. Both theAlarm MIB is not supported. 4. Security Considerations In addition to general syslog security considerations discussed in [Syslog],"resource" and the "resourceURI" parameters point at the resource experiencing the alarm, but the "resourceURI" has syntactic constraint requiring it to be a URI. This makes it easy to correlate this syslog alarm with any alarms that are received via other protocols, such as SNMP or to use SNMP or other protocols to get additional information about this resource. 4. Examples Example 1 - Mandatory Alarm Information <165>1 2003-10-11T22:14:15.003Z mymachine.example.com evntslog - ID47 [exampleSDID@32473 iut="3" eventSource= "Application" eventID="1011"][alarm resource="su root" probableCause="unauthorizedAccessAttempt" perceivedSeverity="major"] BOMAn application event log entry... In this example, extended from [Syslog], the VERSION is 1 and the Facility has the value of 4. The severity is 2. The message was created on 11 October 2003 at 10:14:15pm UTC, 3 milliseconds into the next second. The message originated from a host that identifies itself as "mymachine.example.com". The APP-NAME is "su" and the PROCID is unknown. The MSGID is "ID47". We have included both the structured data from the original example, a single element with the value "[exampleSDID@0 iut="3" eventSource="Application" eventID="1011"]" and a new one with the alarm information defined in this memo. The alarm SD-ID contains the mandatory SD-PARAMS of resource, probableCause and preceivedSeverity. The MSG itself is "An application event log entry..." The BOM at the beginning of MSG indicates UTF-8 encoding. Example 2 - Additional Alarm Information <165>1 2004-11-10T20:15:15.003Z mymachine.example.com evntslog - ID48 [alarm resource="interface 42" probableCause="unauthorizedAccessAttempt" perceivedSeverity="major" eventType="communicationsAlarm" resourceURI ="snmp://example.com//1.3.6.1.2.1.2.2.1.1.42"] In this example, we include two optional alarm fields - eventType and resourceURI. 5. Security Considerations In addition to general syslog security considerations discussed in [RFC5424], the information contained with alarms may provide hackers with helpful information about parts of the system currently experiencing stress as well as general information about the system such as inventory. Users should not have access to information in alarms that their normal access permissions would not permit if the information was accessed in another manner.5.There is no standardized access control model for SYSLOG and hence the ability to filter alarms based on a notion of a receiver identity is at best implementation specific. 6. IANA Considerations IANA is requested to register the SD-IDs and PARAM-NAMEs shown below: SD-ID PARAM-NAME alarm OPTIONALalarmedResourceresource MANDATORY probableCause MANDATORY perceivedSeverity MANDATORY eventType OPTIONAL trendIndication OPTIONALresourceMappingresourceURI OPTIONAL6.7. Acknowledgments Thanks to members of the Syslog and OPSAWG work group who contributed to this specification.7.We'd also like to thank Juergen Schoenwaelder, Dave Harrington, Wes Hardaker and Randy Presuhn for their reviews. 8. References7.1.8.1. Normative References [RFC1738] Berners-Lee, T., Masinter, L., and M. McCahill, "Uniform Resource Locators (URL)", RFC 1738, December 1994. [RFC2119] Bradner, s., "Key words for RFCs to Indicate Requirements Levels", RFC 2119, March 1997. [RFC3877] Chisholm, S. and D. Romascanu, "Alarm Management Information Base (MIB)", RFC 3877, September 2004.[Syslog][RFC4088] Black, D., McCloghrie, K., and J. Schoenwaelder, "Uniform Resource Identifier (URI) Scheme for the Simple Network Management Protocol (SNMP)", RFC 4088, June 2005. [RFC5424] Gerhards,Rainer.,R., "The syslog Protocol",ID draft-ietf-syslog-protocol-19.txt, November 2006. 7.2.RFC 5424, March 2009. 8.2. Informative References [X.733] ITU-T, ""Information Technology - Open Systems Interconnection - System Management: Alarm Reporting Function"", ITU-T X.733, 1992. [X.736] ITU-T, ""Information Technology - Open Systems Interconnection - System Management: Security Alarm Reporting Function"", ITU-T X.736, 1992. Authors' Addresses Sharon Chisholm Nortel 3500 Carling Ave Nepean, Ontario K2H 8E9 Canada Email: schishol@nortel.com Rainer Gerhards Adiscon GmbH Mozartstrasse 21 Grossrinderfeld, BW 97950 Germany Email: rgerhards@adiscon.comFull Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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