Network Working Group J. Schoenwaelder

Network Working Group J. Schoenwaelder
Request for Comments: 4789 International University Bremen
Obsoletes: 1089 T. Jeffree
Updates: 3417 Consultant
Category: Standards Track November 2006

Simple Network Management Protocol (SNMP) over IEEE 802 Networks

Status of This Memo

This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The IETF Trust (2006).

Abstract

This document specifies how Simple Network Management Protocol (SNMP)
messages can be transmitted directly over IEEE 802 networks.

This document obsoletes RFC 1089.

Table of Contents

1. Introduction ....................................................2
1.1. Key Words ..................................................2
2. Definitions .....................................................3
3. SNMP over IEEE 802 Networks .....................................4
3.1. Serialization ..............................................4
3.2. Well-known Values ..........................................4
3.3. IEEE 802.3 Frame Format ....................................5
4. Relationship to Other MIB Modules ...............................5
5. IANA Considerations .............................................6
6. Security Considerations .........................................6
7. Acknowledgments .................................................7
8. References ......................................................7
8.1. Normative References .......................................7
8.2. Informative References .....................................7

Schoenwaelder & Jeffree Standards Track [Page 1]

RFC 4789 SNMP over IEEE 802 November 2006

1. Introduction

This document specifies how Simple Network Management Protocol (SNMP)
messages can be transmitted directly over IEEE 802 networks. For a
detailed overview of the documents that describe the Internet-
Standard management framework, please refer to section 7 of RFC 3410
[RFC3410]. This document supplements the standard SNMP transport
mappings defined in RFC 3417 [RFC3417].

This document obsoletes RFC 1089.

Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. MIB objects are generally
accessed through the Simple Network Management Protocol (SNMP).
Objects in the MIB are defined using the mechanisms defined in the
Structure of Management Information (SMI). This memo specifies a MIB
module that is compliant to the SMIv2, which is described in STD 58,
RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
[RFC2580].

1.1. Key Words

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].

Schoenwaelder & Jeffree Standards Track [Page 2]

RFC 4789 SNMP over IEEE 802 November 2006

2. Definitions

SNMP-IEEE802-TM-MIB DEFINITIONS ::= BEGIN

IMPORTS
MODULE-IDENTITY, OBJECT-IDENTITY, snmpModules, snmpDomains
FROM SNMPv2-SMI;

snmpIeee802TmMib MODULE-IDENTITY
LAST-UPDATED "200611210000Z"
ORGANIZATION "IETF Operations and Management Area"
CONTACT-INFO
"Juergen Schoenwaelder (Editor)
International University Bremen
P.O. Box 750 561
28725 Bremen, Germany

Phone: +49 421 200-3587
EMail: [email protected]

Send comments to <[email protected]>."
DESCRIPTION
"This MIB module defines the SNMP over IEEE 802
transport mapping.

Copyright (C) The IETF Trust (2006). This version
of this MIB module is part of RFC 4789; see the RFC
itself for full legal notices."
REVISION "200611210000Z"
DESCRIPTION
"The initial version, published as RFC 4789."
::= { snmpModules 21 }

snmpIeee802Domain OBJECT-IDENTITY
STATUS current
DESCRIPTION
"The SNMP over IEEE 802 networks transport domain. The
corresponding transport address is of type MacAddress
as defined in the SNMPv2-TC module (RFC 2579)."
REFERENCE "RFC 2579"
::= { snmpDomains 6 }
END

Schoenwaelder & Jeffree Standards Track [Page 3]

RFC 4789 SNMP over IEEE 802 November 2006

3. SNMP over IEEE 802 Networks

This is an optional transport mapping. The need to carry SNMP
directly over an 802 LAN transport in order to allow for the
management of simple devices was identified in applications like the
Two-Port Media Access Control (MAC) Relay, which is being developed
in IEEE 802.1 as project P802.1aj [802.1aj].

SNMP over IEEE 802 networks has some inherent restrictions. Using
the SNMP over IEEE 802 transport mapping restricts messages to a
single logical IEEE 802 LAN, bridged LAN or VLAN. Furthermore, only
a single SNMP engine can be addressed on a given IEEE 802 network
interface. In particular, command generators and notification
receivers, as well as command responders and notification
originators, must share a single transport endpoint.

3.1. Serialization

SNMP messages are serialized, as described in Section 8 of RFC 3417
[RFC3417]. The resulting serialized message is shipped in the data
portion of an IEEE LAN MAC frame.

3.2. Well-known Values

Serialized SNMP messages are sent in IEEE 802.3 frames with an
Ethernet type field of 33100 (hexadecimal 814C).

When serialized SNMP messages are sent in IEEE 802.3 frames (and in
other IEEE 802 MAC frame types that can natively represent Ethernet
type values), an Ethernet type field value of 33100 (hexadecimal
814C) MUST be used as the link layer protocol identifier. In IEEE
802 LANs that use LLC as the means of link layer protocol
identification, such as IEEE 802.11 Wireless LANs, the SNAP
encapsulation method described in subclause 10.5 "Encapsulation of
Ethernet frames over LLC" in [IEEE802] MUST be used.

When an SNMP entity uses this transport mapping, it MUST be capable
of accepting SNMP messages up to and including 484 octets in size.
It is RECOMMENDED that implementations be capable of accepting
messages of up to 1472 octets in size. Implementation of larger
values is encouraged whenever possible.

Schoenwaelder & Jeffree Standards Track [Page 4]

RFC 4789 SNMP over IEEE 802 November 2006

3.3. IEEE 802.3 Frame Format

0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination |
+- -+
| Ethernet |
+- -+
| Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source |
+- -+
| Ethernet |
+- -+
| Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1 0 0 0 0 0 0 1 0 1 0 0 1 1 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SNMP |
+- -+
/ message ... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

(Each tic mark represents one bit.)

4. Relationship to Other MIB Modules

Several core SNMP MIB modules use TDomain/TAddress pairs to identify
SNMP transport endpoints. The SNMP-TARGET-MIB [RFC3413] uses
TDomain/TAddress pairs to identify targets that can be used as
notification receivers. TDomain/TAddress pairs are used by the
NOTIFICATION-LOG-MIB [RFC3014] to record the source from which a
notification was received. The ENTITY-MIB [RFC4133] uses TDomain/
TAddress pairs to provide the transport endpoint of logical entities.

The MIB module contained in this document introduces the object
identifier constant snmpIeee802Domain. This constant can be assigned
to an object of type TDomain to identify an SNMP over IEEE 802
endpoint, in which case the corresponding TAddress will have a value
that conforms to the MacAddress textual convention. By providing
these definitions, it is possible to use the generic MIB modules to
refer to SNMP over IEEE 802 endpoints.

Schoenwaelder & Jeffree Standards Track [Page 5]

RFC 4789 SNMP over IEEE 802 November 2006

5. IANA Considerations

IANA made a MIB OID assignment under the snmpModules branch for the
SNMP-IEEE802-TM-MIB module.

IANA assigned an OID value below snmpDomains for the transport
domain. This first required the setup of a registry for OIDs under
snmpDomains. At the point of this writing, the following assignments
already exist:

Prefix: iso.org.dod.internet.snmpv2.snmpDomains (1.3.6.1.6.1)

Decimal Name Description References
------- ---- ----------- ----------
1 snmpUDPDomain SNMP over UDP [RFC3417]
2 snmpCLNSDomain SNMP over CLNS [RFC3417]
3 snmpCONSDomain SNMP over CONS [RFC3417]
4 snmpDDPDomain SNMP over DDP [RFC3417]
5 snmpIPXDomain SNMP over IPX [RFC3417]

The following assigment has been made:

Decimal Name Description References
------- ---- ----------- ----------
6 snmpIeee802Domain SNMP over IEEE 802 RFC 4789

For new assignments, a specification is required as per [RFC2434].

6. Security Considerations

This module does not define any management objects. Instead, it
defines an OBJECT-IDENTIFIER which may be used by other MIB modules
to identify an SNMP transport mapping. Meaningful security
considerations can only be written in the MIB modules that define
management objects. The MIB module in this document has therefore no
impact on the security of the Internet.

SNMPv1 and SNMPv2c messages are not considered secure. It is
recommended that the implementors consider the use of SNMPv3 messages
and the security features as provided by the SNMPv3 framework.
Specifically, the use of the User-based Security Model STD 62, RFC
3414 [RFC3414] and the View-based Access Control Model STD 62, RFC
3415 [RFC3415] is recommended.

It is then a customer/user responsibility to ensure that the SNMP
entity giving access to a MIB is properly configured to give access
to the objects only to those principals (users) that have legitimate
rights to indeed GET or SET (change) them.

Schoenwaelder & Jeffree Standards Track [Page 6]

RFC 4789 SNMP over IEEE 802 November 2006

7. Acknowledgments

The original SNMP over Ethernet definition was written by Marty
Schoffstall, Chuck Davin, Mark Fedor, and Jeff Case, and published as
RFC 1089 [RFC1089].

Bert Wijnen and Dan Romascanu provided guidance on many aspects of
this revised specification. David Harrington provided useful
comments that improved the presentation.

8. References

8.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2578] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Structure of Management Information Version 2 (SMIv2)",
STD 58, RFC 2578, April 1999.

[RFC2579] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Textual Conventions for SMIv2", STD 58, RFC 2579, April
1999.

[RFC2580] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Conformance Statements for SMIv2", STD 58, RFC 2580,
April 1999.

[RFC3417] Presuhn, R., Ed., "Transport Mappings for the Simple
Network Management Protocol (SNMP)", STD 62, RFC 3417,
December 2002.

[IEEE802] "IEEE Standard for Local Area Networks: Overview and
Architecture", IEEE Std. 802-2001.

[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998.

8.2. Informative References

[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction and Applicability Statements for Internet-
Standard Management Framework", RFC 3410, December 2002.

Schoenwaelder & Jeffree Standards Track [Page 7]

RFC 4789 SNMP over IEEE 802 November 2006

[RFC3413] Levi, D., Meyer, P., and B. Stewart, "Simple Network
Management Protocol (SNMP) Applications", STD 62, RFC
3413, December 2002.

[RFC3414] Blumenthal, U. and B. Wijnen, "User-based Security Model
(USM) for version 3 of the Simple Network Management
Protocol (SNMPv3)", STD 62, RFC 3414, December 2002.

[RFC3415] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based
Access Control Model (VACM) for the Simple Network
Management Protocol (SNMP)", STD 62, RFC 3415, December
2002.

[RFC3014] Kavasseri, R., "Notification Log MIB", RFC 3014, November
2000.

[RFC4133] Bierman, A. and K. McCloghrie, "Entity MIB (Version 3)",
RFC 4133, August 2005.

[RFC1089] Schoffstall, M., Davin, C., Fedor, M., and J. Case, "SNMP
over Ethernet", RFC 1089, February 1989.

[802.1aj] P802.1aj/D1.4 Draft Standard for Local and Metropolitan
Area Networks - Virtual Bridged Local Area Networks -
Amendment 08: Two-Port Media Access Control (MAC) Relay,
IEEE 802.1 Working Group, June 2006, Work in Progress.

Authors' Addresses

Juergen Schoenwaelder
International University Bremen
Campus Ring 1
28725 Bremen
Germany

Phone: +49 421 200-3587
EMail: [email protected]

Tony Jeffree
Consultant
11a Poplar Grove
Sale, Cheshire, M33 3AX
United Kingdom

Phone: +44-161-973-4278
EMail: [email protected]

Schoenwaelder & Jeffree Standards Track [Page 8]

RFC 4789 SNMP over IEEE 802 November 2006

Full Copyright Statement

Copyright (C) The IETF Trust (2006).

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.

This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST,
AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT
THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE.

Intellectual Property

The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.

Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.

The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
[email protected].

Acknowledgement

Funding for the RFC Editor function is currently provided by the
Internet Society.

Schoenwaelder & Jeffree Standards Track [Page 9]