RFC 4318
Definitions of Managed Objects for Bridges with Rapid Spanning Tree Protocol
RFC 4318: Definitions of Managed Objects for Bridges with Rapid Spanning Tree Protocol 🎀
Part 1 of 3 🦋
Okay bestie, the title block first 💅 This is RFC 4318, titled Definitions of Managed Objects for Bridges with Rapid Spanning Tree Protocol. It's from the Network Working Group, written by D. Levi of Nortel Networks and D. Harrington of Effective Software, and it's dated December 2005. The category is Standards Track ✨ The title block doesn't list anything it obsoletes or updates, so there's no drama there 🙈
Status of This Memo 📜
So this document is an Internet standards track protocol for the Internet community, and it's asking everyone for discussion and suggestions for improvements 🫶 For the standardization state and status of this protocol, check the current edition of the "Internet Official Protocol Standards" (STD 1). Distribution of this memo is unlimited, so share it with everyone 🌈
Copyright Notice 🌸
Copyright (C) The Internet Society (2005).
Abstract 💜
Okay, the big picture: this memo defines an SMIv2 MIB module for managing the Rapid Spanning Tree capability that the IEEE P802.1t and P802.1w amendments to IEEE Std 802.1D-1998 added for bridging between Local Area Network (LAN) segments 🔥 The objects here are meant to cover both transparent bridging and bridges connected by subnetworks other than LAN segments. Iconic range 👑
Table of Contents ✨
1. The Internet-Standard Management Framework ......................2
2. Overview ........................................................2
3. Relationship to IEEE 802.1t and 802.1w Amendments ...............2
4. Relation to the BRIDGE-MIB ......................................3
5. Definitions for RSTP-MIB ........................................3
6. Acknowledgements ...............................................10
7. IANA Considerations ............................................10
8. Security Considerations ........................................10
9. Normative References ...........................................11
10. Informative References ........................................121. The Internet-Standard Management Framework 🧚
So if you want the full tea on the current Internet-Standard Management Framework, go read section 7 of RFC 3410 [RFC3410] 📚
Managed objects live in a virtual information store called the Management Information Base, or MIB 🦋 Usually you get to them through the Simple Network Management Protocol (SNMP). The objects get defined using the Structure of Management Information (SMI). This memo specifies a MIB module that's compliant with SMIv2, which is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580 [RFC2580] 💅
2. Overview 🌸
Main character recap: this memo defines an SMIv2 MIB module for managing the Rapid Spanning Tree (RSTP) capability from the IEEE P802.1t [802.1t] and P802.1w [802.1w] amendments to IEEE Std 802.1D-1998 [802.1D-1998]. It's for bridging between Local Area Network (LAN) segments, and the objects work for both transparent bridging and bridges on subnetworks other than LAN segments 🫶
3. Relationship to IEEE 802.1t and 802.1w Amendments 💖
Okay so this part is where the MIB objects get matched up with the Rapid Spanning Tree Protocol from the IEEE P802.1t and IEEE P802.1w amendments to 802.1D-1998 🎀 Here's the mapping, and it is literally the cutest table:
RSTP-MIB Name IEEE 802.1 Reference
dot1dStp
dot1dStpVersion (w) 17.16.1 ForceVersion
dot1dStpTxHoldCount (w) 17.16.6 TxHoldCount
dot1dStpExtPortTable
dot1dStpPortProtocolMigration (w) 17.18.10 mcheck
dot1dStpPortAdminEdgePort (t) 18.3.3 adminEdgePort
dot1dStpPortOperEdgePort (t) 18.3.4 operEdgePort
dot1dStpPortAdminPointToPoint (w) 6.4.3 adminPointToPointMAC
dot1dStpPortOperPointToPoint (w) 6.4.3 operPointToPointMAC
dot1dStpPortAdminPathCost (D) 8.5.5.3 Path CostNow the tea ☕ There were concerns that the 802.1D-2004 edition might bring changes that would break SMI compatibility for the 802.1t and 802.1w managed objects in the MIB modules. So the Bridge MIB working group chose to 'freeze' the technical content of the MIB modules at a level that matches the 802.1t and 802.1w versions. Anything after that is left to the IEEE 802.1 working group 🧠
Heads up: the table below is purely for information. It's the 802.1D-2004 references for the same objects, so you can compare them 👀
RSTP-MIB Name IEEE 802.1D-2004 Reference
dot1dStp
dot1dStpVersion 17.13.4 ForceVersion
dot1dStpTxHoldCount 17.13.12 TxHoldCount
dot1dStpExtPortTable
dot1dStpPortProtocolMigration 17.19.13 mcheck
dot1dStpPortAdminEdgePort 17.13.1 adminEdgePort
dot1dStpPortOperEdgePort 17.19.17 operEdgePort
dot1dStpPortAdminPointToPoint 6.4.3 adminPointToPointMAC
dot1dStpPortOperPointToPoint 6.4.3 operPointToPointMAC
dot1dStpPortAdminPathCost 17.13.11 Path Cost4. Relation to the BRIDGE-MIB 🦋
The objects in the RSTP-MIB supplement the ones in the Bridge MIB [RFC4188], so they work as a team 🫶
The Original BRIDGE-MIB [RFC1493] got updated into an SMIv2-compliant version [RFC4188]. Conformance statements were added, and some description and reference clauses got refreshed too ✨ Some objects also got new interpretations so they'd fit the IEEE 802.1t and 802.1w amendments, which is a whole glow-up 💅
Here's the quick list of what changed. The object dot1dStpPortPathCost32 was added to support IEEE 802.1t 🍓 The permissible values of dot1dStpPriority and dot1dStpPortPriority got clarified for bridges that support IEEE 802.1t or IEEE 802.1w. And the interpretation of dot1dStpTimeSinceTopologyChange got clarified for bridges that support the RSTP 🌈
For all the details, check the updated BRIDGE-MIB [RFC4188] 💜
5. Definitions for RSTP-MIB ✨
okay bestie, this is the actual MIB module 🧚 Everything below is copied exactly, character for character, so every object name, value and reference stays precise 💅
RSTP-MIB DEFINITIONS ::= BEGIN
-- -------------------------------------------------------------
-- MIB for IEEE 802.1w Rapid Spanning Tree Protocol
-- -------------------------------------------------------------
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, Integer32, mib-2
FROM SNMPv2-SMI
TruthValue
FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP
FROM SNMPv2-CONF
dot1dStp, dot1dStpPortEntry
FROM BRIDGE-MIB;
rstpMIB MODULE-IDENTITY
LAST-UPDATED "200512070000Z"
ORGANIZATION "IETF Bridge MIB Working Group"
CONTACT-INFO
"Email: Bridge-mib@ietf.org"
DESCRIPTION
"The Bridge MIB Extension module for managing devices
that support the Rapid Spanning Tree Protocol defined
by IEEE 802.1w.
Copyright (C) The Internet Society (2005). This version of
this MIB module is part of RFC 4318; See the RFC itself for
full legal notices."
REVISION "200512070000Z"
DESCRIPTION
"The initial version of this MIB module as published in
RFC 4318."
::= { mib-2 134 }
-- ---------------------------------------------------------- --
-- subtrees in the RSTP-MIB
-- ---------------------------------------------------------- --
rstpNotifications OBJECT IDENTIFIER ::= { rstpMIB 0 }
rstpObjects OBJECT IDENTIFIER ::= { rstpMIB 1 }
rstpConformance OBJECT IDENTIFIER ::= { rstpMIB 2 }
-- -------------------------------------------------------------
-- Addition to the dot1dStp group
-- -------------------------------------------------------------
dot1dStpVersion OBJECT-TYPE
SYNTAX INTEGER {
stpCompatible(0),
rstp(2)
}
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The version of Spanning Tree Protocol the bridge is
currently running. The value 'stpCompatible(0)'
indicates the Spanning Tree Protocol specified in
IEEE 802.1D-1998 and 'rstp(2)' indicates the Rapid
Spanning Tree Protocol specified in IEEE 802.1w and
clause 17 of 802.1D-2004. The values are directly from
the IEEE standard. New values may be defined as future
versions of the protocol become available.
The value of this object MUST be retained across
reinitializations of the management system."
REFERENCE
"IEEE 802.1w clause 14.8.1, 17.12, 17.16.1"
DEFVAL { rstp }
::= { dot1dStp 16 }
dot1dStpTxHoldCount OBJECT-TYPE
SYNTAX Integer32 (1..10)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The value used by the Port Transmit state machine to limit
the maximum transmission rate.
The value of this object MUST be retained across
reinitializations of the management system."
REFERENCE
"IEEE 802.1w clause 17.16.6"
DEFVAL { 3 }
::= { dot1dStp 17 }
--
-- { dot1dStp 18 } was used to represent dot1dStpPathCostDefault
-- in an earlier version of this MIB. It has since been
-- obsoleted, and should not be used.
--
dot1dStpExtPortTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot1dStpExtPortEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A table that contains port-specific Rapid Spanning Tree
information."
::= { dot1dStp 19 }
dot1dStpExtPortEntry OBJECT-TYPE
SYNTAX Dot1dStpExtPortEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of Rapid Spanning Tree information maintained by
each port."
AUGMENTS { dot1dStpPortEntry }
::= { dot1dStpExtPortTable 1 }
Dot1dStpExtPortEntry ::=
SEQUENCE {
dot1dStpPortProtocolMigration
TruthValue,
dot1dStpPortAdminEdgePort
TruthValue,
dot1dStpPortOperEdgePort
TruthValue,
dot1dStpPortAdminPointToPoint
INTEGER,
dot1dStpPortOperPointToPoint
TruthValue,
dot1dStpPortAdminPathCost
Integer32
}
dot1dStpPortProtocolMigration OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"When operating in RSTP (version 2) mode, writing true(1)
to this object forces this port to transmit RSTP BPDUs.
Any other operation on this object has no effect and
it always returns false(2) when read."
REFERENCE
"IEEE 802.1w clause 14.8.2.4, 17.18.10, 17.26"
::= { dot1dStpExtPortEntry 1 }
dot1dStpPortAdminEdgePort OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The administrative value of the Edge Port parameter. A
value of true(1) indicates that this port should be
assumed as an edge-port, and a value of false(2) indicates
that this port should be assumed as a non-edge-port.
Setting this object will also cause the corresponding
instance of dot1dStpPortOperEdgePort to change to the
same value. Note that even when this object's value
is true, the value of the corresponding instance of
dot1dStpPortOperEdgePort can be false if a BPDU has
been received.
The value of this object MUST be retained across
reinitializations of the management system."
REFERENCE
"IEEE 802.1t clause 14.8.2, 18.3.3"
::= { dot1dStpExtPortEntry 2 }
dot1dStpPortOperEdgePort OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The operational value of the Edge Port parameter. The
object is initialized to the value of the corresponding
instance of dot1dStpPortAdminEdgePort. When the
corresponding instance of dot1dStpPortAdminEdgePort is
set, this object will be changed as well. This object
will also be changed to false on reception of a BPDU."
REFERENCE
"IEEE 802.1t clause 14.8.2, 18.3.4"
::= { dot1dStpExtPortEntry 3 }
dot1dStpPortAdminPointToPoint OBJECT-TYPE
SYNTAX INTEGER {
forceTrue(0),
forceFalse(1),
auto(2)
}
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The administrative point-to-point status of the LAN segment
attached to this port, using the enumeration values of the
IEEE 802.1w clause. A value of forceTrue(0) indicates
that this port should always be treated as if it is
connected to a point-to-point link. A value of
forceFalse(1) indicates that this port should be treated as
having a shared media connection. A value of auto(2)
indicates that this port is considered to have a
point-to-point link if it is an Aggregator and all of its
members are aggregatable, or if the MAC entity
is configured for full duplex operation, either through
auto-negotiation or by management means. Manipulating this
object changes the underlying adminPortToPortMAC.
The value of this object MUST be retained across
reinitializations of the management system."
REFERENCE
"IEEE 802.1w clause 6.4.3, 6.5, 14.8.2"
::= { dot1dStpExtPortEntry 4 }
dot1dStpPortOperPointToPoint OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The operational point-to-point status of the LAN segment
attached to this port. It indicates whether a port is
considered to have a point-to-point connection.
If adminPointToPointMAC is set to auto(2), then the value
of operPointToPointMAC is determined in accordance with the
specific procedures defined for the MAC entity concerned,
as defined in IEEE 802.1w, clause 6.5. The value is
determined dynamically; that is, it is re-evaluated whenever
the value of adminPointToPointMAC changes, and whenever
the specific procedures defined for the MAC entity evaluate
a change in its point-to-point status."
REFERENCE
"IEEE 802.1w clause 6.4.3, 6.5, 14.8.2"
::= { dot1dStpExtPortEntry 5 }
dot1dStpPortAdminPathCost OBJECT-TYPE
SYNTAX Integer32 (0..200000000)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The administratively assigned value for the contribution
of this port to the path cost of paths toward the spanning
tree root.
Writing a value of '0' assigns the automatically calculated
default Path Cost value to the port. If the default Path
Cost is being used, this object returns '0' when read.
This complements the object dot1dStpPortPathCost or
dot1dStpPortPathCost32, which returns the operational value
of the path cost.
The value of this object MUST be retained across
reinitializations of the management system."
REFERENCE
"IEEE 802.1D-1998: Section 8.5.5.3"
::= { dot1dStpExtPortEntry 6 }
-- -------------------------------------------------------------
-- rstpMIB - Conformance Information
-- -------------------------------------------------------------
rstpGroups OBJECT IDENTIFIER ::= { rstpConformance 1 }
rstpCompliances OBJECT IDENTIFIER ::= { rstpConformance 2 }
-- -------------------------------------------------------------
-- Units of conformance
-- -------------------------------------------------------------
rstpBridgeGroup OBJECT-GROUP
OBJECTS {
dot1dStpVersion,
dot1dStpTxHoldCount
}
STATUS current
DESCRIPTION
"Rapid Spanning Tree information for the bridge."
::= { rstpGroups 1 }
rstpPortGroup OBJECT-GROUP
OBJECTS {
dot1dStpPortProtocolMigration,
dot1dStpPortAdminEdgePort,
dot1dStpPortOperEdgePort,
dot1dStpPortAdminPointToPoint,
dot1dStpPortOperPointToPoint,
dot1dStpPortAdminPathCost
}
STATUS current
DESCRIPTION
"Rapid Spanning Tree information for individual ports."
::= { rstpGroups 2 }
-- -------------------------------------------------------------
-- Compliance statements
-- -------------------------------------------------------------
rstpCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for device support of Rapid
Spanning Tree Protocol (RSTP) bridging services."
MODULE
MANDATORY-GROUPS {
rstpBridgeGroup,
rstpPortGroup
}
::= { rstpCompliances 1 }
END6. Acknowledgements ✨
This doc was produced on behalf of the Bridge MIB Working Group in the Operations and Management area of the Internet Engineering Task Force. 🌸
The authors want to thank the members of the Bridge MIB Working Group, especially Alex Ruzin, for their comments and suggestions that made this effort so much better. 🫶
Vivian Ngai and Les Bell were the initial authors and did the bulk of the development work. Literally the MVPs 👑
7. IANA Considerations 🎀
The IANA has assigned the following OID:
Descriptor OBJECT IDENTIFIER value
---------- -----------------------
rstpMIB { mib-2 134 }8. Security Considerations 🔐
Okay bestie, this section is serious, so read it slowly 🫣 There are a bunch of management objects in this MIB module with a MAX-ACCESS clause of read-write and/or read-create. These objects may be considered sensitive or vulnerable in some network environments. Supporting SET operations in a non-secure environment without proper protection can totally mess with network operations. 💀 Here are the tables and objects and why they're sensitive or vulnerable:
Writable objects that could be misused to cause network delays and spanning tree instabilities include dot1dStpVersion, dot1dStpTxHoldCount, dot1dStpPortProtocolMigration, dot1dStpPortAdminEdgePort, and dot1dStpPortAdminPathCost. ⚠️
Some of the readable objects in this MIB module (meaning objects with a MAX-ACCESS other than not-accessible) may be considered sensitive or vulnerable in some network environments. So it's important to control even GET and/or NOTIFY access to these objects, and possibly even encrypt their values when sending them over the network via SNMP. 🙈 Here are the tables and objects and their sensitivity/vulnerability:
dot1dStpVersion could be read by an attacker to identify environments containing applications or protocols that are potentially sensitive to RSTP mode. 👀
dot1dStpPortAdminPointToPoint could be used to mislead an access control protocol, such as 802.1x, into believing that only one other system is attached to a LAN segment, and to enable network access based on that assumption. This situation could permit potential man-in-the-middle attacks. 😭
SNMP versions prior to SNMPv3 did not include adequate security. Even if the network itself is secure (for example by using IPsec), there is still no control over who on that secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB module. Not me being like "wait, anyone can just do that??" 💅
It is RECOMMENDED that implementers consider the security features provided by the SNMPv3 framework (see [RFC3410], section 8), including full support for the SNMPv3 cryptographic mechanisms (for authentication and privacy). 🔒
Further, deployment of SNMP versions prior to SNMPv3 is NOT RECOMMENDED. Instead, it is RECOMMENDED to deploy SNMPv3 and enable cryptographic security. It is then a customer/operator responsibility to make sure that the SNMP entity giving access to an instance of this MIB module is properly configured, so the objects are only accessible to those principals (users) who have legitimate rights to GET or SET (change/create/delete) them. The main character energy of responsible ops is everything 👑
9. Normative References 📚
[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.[802.1D-1998]"Information technology - Telecommunications and information exchange between systems - Local and metropolitan area networks - Common specifications - Part 3: Media Access Control (MAC) Bridges: Revision. This is a revision of ISO/IEC 10038: 1993, 802.1j-1992 and 802.6k-1992. It incorporates P802.11c, P802.1p and P802.12e." ISO/IEC 15802-3: 1998.[RFC4188]Norseth, K. and E. Bell, "Definitions of Managed Objects for Bridges", RFC 4188, September 2005.[802.1t]IEEE 802.1t-2001, "(Amendment to IEEE Standard 802.1D) IEEE Standard for Information technology - Telecommunications and information exchange between systems - Local and metropolitan area networks - Common specifications - Part 3: Media Access Control (MAC) Bridges: Technical and Editorial Corrections".[802.1w]IEEE 802.1w-2001, "(Amendment to IEEE Standard 802.1D) IEEE Standard for Information technology-- Telecommunications and information exchange between systems--Local and metropolitan area networks--Common Specifications--Part 3: Media Access Control (MAC) Bridges: Rapid Reconfiguation".
10. 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.[802.1D-2004]IEEE Project 802 Local and Metropolitan Area Networks, "IEEE Standard 802.1D-2004 MAC Bridges", 2004.[RFC1493]Decker, E., Langille, P., Rijsinghani, A., and K. McCloghrie, "Definitions of Managed Objects for Bridges", RFC 1493, July 1993.
Authors' Addresses 💌
David Levi
Nortel Networks
4655 Great America Parkway
Santa Clara, CA 95054
USA
Phone: +1 408 495 5138
EMail: dlevi@nortel.com
David Harrington
Effective Software
50 Harding Rd.
Portsmouth, NH 03801
USA
Phone: +1 603 436 8634
EMail: ietfdbh@comcast.net
Les Bell
Hemel Hempstead
Herts. HP2 7YU
UK
EMail: elbell@ntlworld.com
Vivian Ngai
Salt lake City, UT
USA
EMail: vivian_ngai@acm.orgFull Copyright Statement ©️
Copyright (C) The Internet Society (2005).
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 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. It also doesn't represent that it has made any independent effort to identify any such rights. Info on the procedures for 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 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 ietf-ipr@ietf.org. 💜
Acknowledgement 🫶
Funding for the RFC Editor function is currently provided by the Internet Society. ✨
📦 where this page comes from
- ietf: rfc4318 2005-12
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