Internet Draft V. Ngai Expires August 2004 Enterasys Networks draft-ietf-bridge-rstpmib-04.txt E. Bell 3Com Corp. March 2004 Definitions of Managed Objects for Bridges with Rapid Spanning Tree Protocol Status of this Memo This document is an Internet-Draft and is subject to all provisions of Section 10 of RFC2026. 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 as 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/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP based internets. In particular, it defines a MIB module for managing the Rapid Spanning Tree capability defined by the IEEE P802.1t [802.1t] and P802.1w [802.1w] amendments to IEEE Std 802.1D-1998 for bridging between Local Area Network (LAN) segments. Provisions are made for support of transparent bridging. Provisions are also made so that these objects apply to bridges connected by subnetworks other than LAN segments. This memo also includes a MIB module in a manner that is compliant to SMIv2 [RFC2578]. Ngai et. al Expires August 2004 [Page 1] Internet Draft RSTP (802.1w) MIBs March 2004 This memo supplements RFC 1493 [BRIDGEMIB] and RFC 2674 [Q-BRIDGE- MIB]. Table of Contents 1 The SNMP Management Framework ................................ 3 2 Overview ..................................................... 4 2.1 Scope ...................................................... 4 3 Structure of MIBs ............................................ 4 3.1 Structure of RSTP-MIB ...................................... 4 3.4 Relationship to Other MIBs ................................. 5 3.4.1 Relationship to Original Bridge MIB ...................... 5 3.4.1.1 The dot1dBase Group .................................... 5 3.4.1.2 The dot1dStp Group ..................................... 5 3.4.1.3 The dot1dTp Group ...................................... 6 3.4.1.4 The dot1dStatic Group .................................. 6 4 Definition for RSTP-MIB ...................................... 7 5 Acknowledgments .............................................. 13 6 Security consideration ....................................... 13 7 References ................................................... 14 8 Authors' Addresses ........................................... 16 9 Intellectual Property ........................................ 17 10 Full Copyright .............................................. 18 Ngai et. al Expires August 2004 [Page 2] Internet Draft RSTP (802.1w) MIBs March 2004 1. The SNMP Management Framework The SNMP Management Framework presently consists of five major components: o An overall architecture, described in RFC 2571 [RFC2571]. o Mechanisms for describing and naming objects and events for the purpose of management. The first version of this Structure of Management Information (SMI) is called SMIv1 and described in STD 16, RFC 1155 [RFC1155], STD 16, RFC 1212 [RFC1212] and RFC 1215 [RFC1215]. The second version, called SMIv2, is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580 [RFC2580]. o Message protocols for transferring management information. The first version of the SNMP message protocol is called SNMPv1 and described in STD 15, RFC 1157 [RFC1157]. A second version of the SNMP message protocol, which is not an Internet standards track protocol, is called SNMPv2c and described in RFC 1901 [RFC1901] and RFC 1906 [RFC1906]. The third version of the message protocol is called SNMPv3 and described in RFC 1906 [RFC1906], RFC 2572 [RFC2572] and RFC 2574 [RFC2574]. o Protocol operations for accessing management information. The first set of protocol operations and associated PDU formats is described in STD 15, RFC 1157 [RFC1157]. A second set of protocol operations and associated PDU formats is described in RFC 1905 [RFC1905]. o A set of fundamental applications described in RFC 2573 [RFC2573] and the view-based access control mechanism described in RFC 2575 [RFC2575]. A more detailed introduction to the current SNMP Management Framework can be found in RFC 2570 [RFC2570]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the mechanisms defined in the SMI. This memo specifies a MIB module that is compliant to the SMIv2. A MIB conforming to the SMIv1 can be produced through the appropriate translations. The resulting translated MIB must be semantically equivalent, except where objects or events are omitted because no translation is possible (use of Counter64). Some machine readable information in SMIv2 will be converted into textual descriptions in SMIv1 during the translation process. However, this loss of machine Ngai et. al Expires August 2004 [Page 3] Internet Draft RSTP (802.1w) MIBs March 2004 readable information is not considered to change the semantics of the MIB. 2. Overview A common device present in many networks is the Bridge. This device is used to connect Local Area Network segments below the network layer. These devices are often known as 'layer 2 switches'. There are two major modes defined for this bridging: Source-Route and transparent. Source-Route bridging is described by IEEE 802.5 [802.5] and is not discussed further in this document. The transparent method of bridging is defined by IEEE 802.1D-1998 [802.1D] Managed objects for that original specification of transparent bridging were defined in RFC 1493 [BRIDGEMIB]. 2.1. Scope This MIB includes a comprehensive set of managed objects which attempts to match the set defined in IEEE P802.1t [802.1t] and P802.1w [802.1w]. 3. Structure of MIBs This document defines additional managed objects for Rapid Spanning Tree Protocol defined by IEEE P802.1t and IEEE P802.1w, on top of those existing in the original BRIDGE-MIB module defined in [BRIDGEMIB]: that MIB module is to be maintained unchanged for backwards compatibility. Section 3.4.1 of the present document contains some recommendations regarding usage of objects in the original bridge MIB by devices implementing the enhancements defined here. 3.1. Structure of RSTP-MIB Objects in this MIB are defined as an addition to the dot1dStp group in the original bridge MIB [BRIDGE-MIB]. The overall structure is shown below: Ngai et. al Expires August 2004 [Page 4] Internet Draft RSTP (802.1w) MIBs March 2004 Bridge MIB Name IEEE 802.1 Reference dot1dStp dot1dStpVersion (w) 17.16.1 ForceVersion dot1dStpTxHoldCount (w) 17.16.6 TxHoldCount dot1dStpPathCostDefault 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 Cost 3.4. Relationship to Other MIBs As described above, some IEEE 802.1D management objects have not been included in this MIB because they overlap with objects in other MIBs applicable to a bridge implementing this MIB. In particular, it is assumed that a bridge implementing this MIB will implement the original bridge MIB [BRIDGEMIB]. 3.4.1. Relation to Original Bridge MIB This section defines how objects in the original bridge MIB module [BRIDGEMIB] should be represented for devices which implement all the MIB modules described in this memo. Some of the old objects are less useful in such devices but must still be implemented for reasons of backwards compatibility. 3.4.1.1. The dot1dBase Group This mandatory group contains the objects which are applicable to all types of bridges. Interpretation of this group is unchanged. 3.4.1.2. The dot1dStp Group This group contains the objects that denote the bridge's state with respect to the Spanning Tree Protocol. If a node does not implement the Spanning Tree Protocol, this group will not be implemented. In a device supporting the Spanning Tree Algorithm and Protocol defined in IEEE 802.1D-1998 Clause 8, interpretation of this group is unchanged. In a device supporting the Rapid Spanning Tree Algorithm and Protocol defined in IEEE 802.1w Clause 17, the interpretation of objects in this group is unchanged except for those listed below: Ngai et. al Expires August 2004 [Page 5] Internet Draft RSTP (802.1w) MIBs March 2004 dot1dStpPriority Definition remains unchanged, but the permissible values are changed to 0-61440, in steps of 4096. dot1dStpPortPriority Definition remains unchanged, but the permissible values are changed to 0-240, in steps of 16. dot1dStpTimeSinceTopologyChange The time since the tcWhile timer for any port on this Bridge was non-zero. dot1dStpTopChanges The number of times that there have been at least one non-zero tcWhile timer on this Bridge. In a device supporting the 32-bit default Path Costs defined in IEEE 802.1t Table 8-5, the interpretation of objects in this group is unchanged except for the following: dot1dStpPortPathCost Definition remains unchanged, but the permissible values are extended to 1-200,000,000. 3.4.1.3. The dot1dTp Group This group contains objects that describe the entity's state with respect to transparent bridging. Interpretation for this group is unchanged. 3.4.1.4. The dot1dStatic Group This group contains objects that describe the entity's state with respect to destination-address filtering. Interpretation for this group is unchanged. Ngai et. al Expires August 2004 [Page 6] Internet Draft RSTP (802.1w) MIBs March 2004 4. Definitions for RSTP-MIB RSTP-MIB DEFINITIONS ::= BEGIN -- ------------------------------------------------------------- -- MIB for IEEE 802.1w Rapid Spanning Tree Protocol -- ------------------------------------------------------------- IMPORTS MODULE-IDENTITY, OBJECT-TYPE, Integer32 FROM SNMPv2-SMI TruthValue FROM SNMPv2-TC MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF dot1dBridge, dot1dStp, dot1dStpPortEntry FROM BRIDGE-MIB; rstpMIB MODULE-IDENTITY LAST-UPDATED "200403210000Z" 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." REVISION "200403210000Z" DESCRIPTION "Draft 4" ::= { dot1dBridge 11 } -- ------------------------------------------------------------- -- 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 and 'rstp(2)' indicates the Rapid Spanning Ngai et. al Expires August 2004 [Page 7] Internet Draft RSTP (802.1w) MIBs March 2004 Tree Protocol specified in IEEE 802.1w. New value may be defined as future versions of the protocol become available." 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." REFERENCE "IEEE 802.1w clause 17.16.6" DEFVAL { 3 } ::= { dot1dStp 17 } dot1dStpPathCostDefault OBJECT-TYPE SYNTAX INTEGER { stp8021d1998(1), stp8021t2001(2) } MAX-ACCESS read-write STATUS current DESCRIPTION "The version of the Spanning Tree default Path Costs that are to be used by this Bridge. A value of 8021d1998(1) uses the 16-bit default Path Costs from IEEE Std. 802.1D-1998. A value of stp8021t2001(2) uses the 32-bit default Path Costs from IEEE Std. 802.1t." REFERENCE "IEEE 802.1D & 802.1t Table 8-5" ::= { dot1dStp 18 } 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 Ngai et. al Expires August 2004 [Page 8] Internet Draft RSTP (802.1w) MIBs March 2004 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." REFERENCE "IEEE 802.1t clause 14.8.2, 18.3.3" Ngai et. al Expires August 2004 [Page 9] Internet Draft RSTP (802.1w) MIBs March 2004 ::= { 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 dot1dStpPortAdminEdgePort and is set 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. 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." 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 or not. The value is determined by management or by auto-detection, as described in the dot1dStpPortAdminPointToPoint object." Ngai et. al Expires August 2004 [Page 10] Internet Draft RSTP (802.1w) MIBs March 2004 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 towards 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." REFERENCE "IEEE 802.1D-1998: Section 8.5.5.3" ::= { dot1dStpExtPortEntry 6 } -- ------------------------------------------------------------- -- rstpMIB - Conformance Information -- ------------------------------------------------------------- rstpConformance OBJECT IDENTIFIER ::= { rstpMIB 1 } 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 } Ngai et. al Expires August 2004 [Page 11] Internet Draft RSTP (802.1w) MIBs March 2004 rstpDefaultPathCostGroup OBJECT-GROUP OBJECTS { dot1dStpPathCostDefault } STATUS current DESCRIPTION "Default Spanning Tree path cost information." ::= { rstpGroups 2 } rstpPortGroup OBJECT-GROUP OBJECTS { dot1dStpPortProtocolMigration, dot1dStpPortAdminEdgePort, dot1dStpPortOperEdgePort, dot1dStpPortAdminPointToPoint, dot1dStpPortOperPointToPoint, dot1dStpPortAdminPathCost } STATUS current DESCRIPTION "Rapid Spanning Tree information for individual ports." ::= { rstpGroups 3 } -- ------------------------------------------------------------- -- Compliance statements -- ------------------------------------------------------------- rstpCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "The compliance statement for device support of bridging services." MODULE MANDATORY-GROUPS { rstpBridgeGroup, rstpPortGroup } GROUP rstpDefaultPathCostGroup DESCRIPTION "Support for this group is mandatory only if both 16-bit and 32-bit Path Costs are supported." ::= { rstpCompliances 1 } END Ngai et. al Expires August 2004 [Page 12] Internet Draft RSTP (802.1w) MIBs March 2004 5. Acknowledgments This document was produced on behalf of the Bridge MIB Working Group in the Operations and Management area of the Internet Engineering Task Force. The authors wish to thank the members of the Bridge MIB Working Group, especially Alex Ruzin, for their comments and suggestions which improved this effort. 6. Security Considerations There are a number of management objects defined in this MIB that have a MAX-ACCESS clause of read-write and/or read-create. Such objects may be considered sensitive or vulnerable in some network environments. The support for SET operations in a non-secure environment without proper protection can have a negative effect on network operations. SNMPv1 by itself is not a secure environment. Even if the network itself is secure (for example by using IPSec), even then, there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB. It is recommended that the implementers consider the security features as provided by the SNMPv3 framework. Specifically, the use of the User-based Security Model [USM] and the View-based Access Control Model [VACM] is recommended. Ngai et. al Expires August 2004 [Page 13] Internet Draft RSTP (802.1w) MIBs March 2004 7. References [RFC2571] Harrington, D., Presuhn, R., and B. Wijnen, An Architecture for Describing SNMP Management Frameworks, RFC 2571, April 1999. [RFC1155] Rose, M., and K. McCloghrie, Structure and Identification of Management Information for TCP/IP-based Internets, STD 16, RFC 1155, May 1990. [RFC1212] Rose, M., and K. McCloghrie, Concise MIB Definitions, STD 16, RFC 1212, March 1991. [RFC1215] M. Rose, A Convention for Defining Traps for use with the SNMP, RFC 1215, March 1991. [RFC2578] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, Structure of Management Information Version 2 (SMIv2), STD 58, RFC 2578, April 1999. [RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, Textual Conventions for SMIv2, STD 58, RFC 2579, April 1999. [RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M., and S. Waldbusser, Conformance Statements for SMIv2, STD 58, RFC 2580, April 1999. [RFC1157] Case, J., Fedor, M., Schoffstall, M., and J. Davin, Simple Network Management Protocol, STD 15, RFC 1157, May 1990. [RFC1901] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, Introduction to Community-based SNMPv2, RFC 1901, January 1996. [RFC1906] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, Transport Mappings for Version 2 of the Simple Network Management Protocol (SNMPv2), RFC 1906, January 1996. [RFC2572] Case, J., Harrington D., Presuhn R., and B. Wijnen, Message Processing and Dispatching for the Simple Network Management Protocol (SNMP), RFC 2572, April 1999. [RFC2574] Blumenthal, U., and B. Wijnen, User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3), RFC 2574, April 1999. Ngai et. al Expires August 2004 [Page 14] Internet Draft RSTP (802.1w) MIBs March 2004 [RFC1905] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, Protocol Operations for Version 2 of the Simple Network Management Protocol (SNMPv2), RFC 1905, January 1996. [RFC2573] Levi, D., Meyer, P., and B. Stewart, SNMPv3 Applications, RFC 2573, April 1999. [RFC2575] Wijnen, B., Presuhn, R., and K. McCloghrie, View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP), RFC 2575, April 1999. [RFC2570] Case, J., Mundy, R., Partain, D., and B. Stewart, Introduction to Version 3 of the Internet-standard Network Management Framework, RFC 2570, April 1999. [RFC2674] Bell, E., Smith, A., Langille, P., Rijhsinghani, A. and McCloghrie, "Definitions of Managed Objects for Bridges with Traffic Classes, Multicast Filtering and Virtual LAN Extensions", RFC 2674, August 1999. [802.1D] "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. [BRIDGEMIB] Decker, E., Langille, P., Rijsinghani, A. and K. McCloghrie, "Definitions of Managed Objects for Bridges", RFC 1493, July 1993. [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". Ngai et. al Expires August 2004 [Page 15] Internet Draft RSTP (802.1w) MIBs March 2004 9. Authors' Addresses Les Bell 3Com Europe Limited eCom Centre, Boundary Way Hemel Hempstead Herts. HP2 7YU UK Phone: +44 1442 438025 Email: Les_Bell@3Com.com Vivian Ngai Enterasys Networks 2691 South Decker Lake Lane Salt Lake City, UT 84119 USA Phone: +1 801 556 5652 Email: vivian_ngai@acm.org Ngai et. al Expires August 2004 [Page 16] Internet Draft RSTP (802.1w) MIBs March 2004 9. Intellectual Property The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication 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 implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Ngai et. al Expires August 2004 [Page 17] Internet Draft RSTP (802.1w) MIBs March 2004 10. Full Copyright Copyright (C) The Internet Society (2004). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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. Ngai et. al Expires August 2004 [Page 18]