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Network Working Group Request for Comments: 2933 Category: Standards Track |
K. McCloghrie cisco Systems D. Farinacci Procket Networks D. Thaler Microsoft October 2000 |
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 © The Internet Society (2000). All Rights Reserved.
This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes objects used for managing the Internet Group Management Protocol (IGMP).
1 Introduction
2 The SNMP Network Management Framework
3 Overview
4 Definitions
5 Security Considerations
6 Intellectual Property Notice
7 Acknowledgements
8 Authors' Addresses
9 References
10 Full Copyright Statement
This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes objects used for managing the Internet
Group Management Protocol (IGMP), version 1 [16] or version 2 [17]. A future version of this MIB will support IGMP version 3 (currently a work in progress). All of this MIB module is applicable to IPv4 multicast routers; a subset is applicable to hosts implementing IGMP. Since IGMP is specific to IPv4, this MIB does not support management of equivalent functionality for other address families, such as IPv6. Such management may be supported by other MIBs.
The SNMP Management Framework presently consists of five major components:
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 readable information is not considered to change the semantics of the MIB.
This MIB module contains two tables:
(1) the IGMP Interface Table which contains one row for each interface on which IGMP is enabled, and
(2) the IGMP Cache Table which contains one row for each IP multicast group for which there are members on a particular interface.
Both tables are intended to be implemented by hosts and routers, but some columnar objects in each table apply only to routers.
IGMP-STD-MIB DEFINITIONS ::= BEGIN
RowStatus, TruthValue FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF
InterfaceIndexOrZero,
InterfaceIndex FROM IF-MIB;
Phone: +1 425 703 8835
EMail: dthaler@microsoft.com"
DESCRIPTION
"The MIB module for IGMP Management."
REVISION "200009280000Z" -- September 28, 2000
DESCRIPTION
"Initial version, published as RFC 2933."
::= { mib-2 85 }
igmpMIBObjects OBJECT IDENTIFIER ::= { igmpStdMIB 1 }
--
-- The IGMP Interface Table
--
SYNTAX SEQUENCE OF IgmpInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the interfaces on which IGMP
is enabled."
::= { igmpMIBObjects 1 }
SYNTAX IgmpInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) representing an interface on
which IGMP is enabled."
INDEX { igmpInterfaceIfIndex }
::= { igmpInterfaceTable 1 }
IgmpInterfaceEntry ::= SEQUENCE {
igmpInterfaceIfIndex InterfaceIndex,
igmpInterfaceQueryInterval Unsigned32,
igmpInterfaceStatus RowStatus,
igmpInterfaceVersion Unsigned32,
igmpInterfaceQuerier IpAddress,
igmpInterfaceQueryMaxResponseTime Unsigned32,
igmpInterfaceQuerierUpTime TimeTicks,
igmpInterfaceQuerierExpiryTime TimeTicks,
igmpInterfaceVersion1QuerierTimer TimeTicks,
igmpInterfaceWrongVersionQueries Counter32,
igmpInterfaceJoins Counter32,
igmpInterfaceProxyIfIndex InterfaceIndexOrZero,
igmpInterfaceGroups Gauge32,
igmpInterfaceRobustness Unsigned32,
igmpInterfaceLastMembQueryIntvl Unsigned32
}
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The ifIndex value of the interface for which IGMP is
enabled."
::= { igmpInterfaceEntry 1 }
SYNTAX Unsigned32
UNITS "seconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The frequency at which IGMP Host-Query packets are
transmitted on this interface."
DEFVAL { 125 }
::= { igmpInterfaceEntry 2 }
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The activation of a row enables IGMP on the interface. The
destruction of a row disables IGMP on the interface."
::= { igmpInterfaceEntry 3 }
SYNTAX Unsigned32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The version of IGMP which is running on this interface.
This object can be used to configure a router capable of
running either value. For IGMP to function correctly, all
routers on a LAN must be configured to run the same version
of IGMP on that LAN."
DEFVAL { 2 }
::= { igmpInterfaceEntry 4 }
SYNTAX IpAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The address of the IGMP Querier on the IP subnet to which
this interface is attached."
::= { igmpInterfaceEntry 5 }
SYNTAX Unsigned32 (0..255)
UNITS "tenths of seconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The maximum query response time advertised in IGMPv2
queries on this interface."
DEFVAL { 100 }
::= { igmpInterfaceEntry 6 }
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time since igmpInterfaceQuerier was last changed."
::= { igmpInterfaceEntry 7 }
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The amount of time remaining before the Other Querier
Present Timer expires. If the local system is the querier,
the value of this object is zero."
::= { igmpInterfaceEntry 8 }
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time remaining until the host assumes that there are no
IGMPv1 routers present on the interface. While this is non-
zero, the host will reply to all queries with version 1
membership reports."
::= { igmpInterfaceEntry 9 }
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of queries received whose IGMP version does not match igmpInterfaceVersion, over the lifetime of the row entry. IGMP requires that all routers on a LAN be configured to run the same version of IGMP. Thus, if any queries are received with the wrong version, this indicates a configuration error."
::= { igmpInterfaceEntry 10 }
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of times a group membership has been added on
this interface; that is, the number of times an entry for
this interface has been added to the Cache Table. This
object gives an indication of the amount of IGMP activity
over the lifetime of the row entry."
::= { igmpInterfaceEntry 11 }
SYNTAX InterfaceIndexOrZero
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Some devices implement a form of IGMP proxying whereby
memberships learned on the interface represented by this
row, cause IGMP Host Membership Reports to be sent on the
interface whose ifIndex value is given by this object. Such
a device would implement the igmpV2RouterMIBGroup only on
its router interfaces (those interfaces with non-zero
igmpInterfaceProxyIfIndex). Typically, the value of this
object is 0, indicating that no proxying is being done."
DEFVAL { 0 }
::= { igmpInterfaceEntry 12 }
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The current number of entries for this interface in the
Cache Table."
::= { igmpInterfaceEntry 13 }
SYNTAX Unsigned32 (1..255)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The Robustness Variable allows tuning for the expected
packet loss on a subnet. If a subnet is expected to be
lossy, the Robustness Variable may be increased. IGMP is
robust to (Robustness Variable-1) packet losses."
DEFVAL { 2 }
::= { igmpInterfaceEntry 14 }
SYNTAX Unsigned32 (0..255)
UNITS "tenths of seconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The Last Member Query Interval is the Max Response Time
inserted into Group-Specific Queries sent in response to
Leave Group messages, and is also the amount of time between
Group-Specific Query messages. This value may be tuned to
modify the leave latency of the network. A reduced value
results in reduced time to detect the loss of the last
member of a group. The value of this object is irrelevant
if igmpInterfaceVersion is 1."
DEFVAL { 10 }
::= { igmpInterfaceEntry 15 }
--
-- The IGMP Cache Table
--
SYNTAX SEQUENCE OF IgmpCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The (conceptual) table listing the IP multicast groups for
which there are members on a particular interface."
::= { igmpMIBObjects 2 }
SYNTAX IgmpCacheEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry (conceptual row) in the igmpCacheTable."
INDEX { igmpCacheAddress, igmpCacheIfIndex }
::= { igmpCacheTable 1 }
IgmpCacheEntry ::= SEQUENCE {
igmpCacheAddress IpAddress,
igmpCacheIfIndex InterfaceIndex,
igmpCacheSelf TruthValue,
igmpCacheLastReporter IpAddress,
igmpCacheUpTime TimeTicks,
igmpCacheExpiryTime TimeTicks,
igmpCacheStatus RowStatus,
igmpCacheVersion1HostTimer TimeTicks
}
SYNTAX IpAddress
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The IP multicast group address for which this entry
contains information."
::= { igmpCacheEntry 1 }
SYNTAX InterfaceIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The interface for which this entry contains information for
an IP multicast group address."
::= { igmpCacheEntry 2 }
SYNTAX TruthValue
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An indication of whether the local system is a member of
this group address on this interface."
DEFVAL { true }
::= { igmpCacheEntry 3 }
SYNTAX IpAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The IP address of the source of the last membership report
received for this IP Multicast group address on this
interface. If no membership report has been received, this
object has the value 0.0.0.0."
::= { igmpCacheEntry 4 }
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time elapsed since this entry was created."
::= { igmpCacheEntry 5 }
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The minimum amount of time remaining before this entry will
be aged out. A value of 0 indicates that the entry is only
present because igmpCacheSelf is true and that if the router
left the group, this entry would be aged out immediately.
Note that some implementations may process membership
reports from the local system in the same way as reports
from other hosts, so a value of 0 is not required."
::= { igmpCacheEntry 6 }
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this entry."
::= { igmpCacheEntry 7 }
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time remaining until the local router will assume that
there are no longer any IGMP version 1 members on the IP
subnet attached to this interface. Upon hearing any IGMPv1
Membership Report, this value is reset to the group
membership timer. While this time remaining is non-zero,
the local router ignores any IGMPv2 Leave messages for this
group that it receives on this interface."
::= { igmpCacheEntry 8 }
-- conformance information
OBJECT IDENTIFIER ::= { igmpStdMIB 2 }
OBJECT IDENTIFIER ::= { igmpMIBConformance 1 }
igmpMIBGroups OBJECT IDENTIFIER ::= { igmpMIBConformance 2 }
-- compliance statements
OBJECT igmpInterfaceStatus
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT igmpCacheStatus
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
::= { igmpMIBCompliances 1 }
OBJECT igmpInterfaceStatus
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT igmpCacheStatus
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
::= { igmpMIBCompliances 2 }
OBJECT igmpInterfaceStatus
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT igmpCacheStatus
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
::= { igmpMIBCompliances 3 }
OBJECT igmpInterfaceStatus
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
OBJECT igmpCacheStatus
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
::= { igmpMIBCompliances 4 }
-- units of conformance
::= { igmpMIBGroups 1 }
::= { igmpMIBGroups 2 }
::= { igmpMIBGroups 3 }
::= { igmpMIBGroups 4 }
igmpInterfaceLastMembQueryIntvl,
igmpCacheVersion1HostTimer
}
STATUS current
DESCRIPTION
"A collection of additional objects for management of IGMP
version 2 in routers."
::= { igmpMIBGroups 5 }
::= { igmpMIBGroups 6 }
This MIB contains readable objects whose values provide information related to multicast sessions. Some of these objects could contain sensitive information. In particular, the igmpCacheSelf and igmpCacheLastReporter can be used to identify machines which are listening to a given group address. There are also a number of objects that have a MAX-ACCESS clause of read-write and/or read- create, which allow an administrator to configure IGMP in the router.
While unauthorized access to the readable objects is relatively innocuous, unauthorized access to the write-able objects could cause a denial of service. Hence, 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 such an insecure 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 SET (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 RFC 2574 [12] and the View-based Access Control Model RFC 2575 [15] is recommended.
It is then a customer/user responsibility to ensure that the SNMP entity giving access to this MIB, is properly configured to give access to those objects only to those principals (users) that have legitimate rights to access them.
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 implementers 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.
This MIB module was updated based on feedback from the IETF's Inter- Domain Multicast Routing (IDMR) Working Group.
Keith McCloghrie
cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
Phone: +1 408 526 5260
EMail: kzm@cisco.com
Dino Farinacci
Procket Networks
3850 North First Street
San Jose, CA 95134
Phone: +1 408-954-7909
Email: dino@procket.com
Dave Thaler
Microsoft Corporation
One Microsoft Way
Redmond, WA 48105-6399
Phone: +1 425 703 8835
EMail: dthaler@microsoft.com
[1] Wijnen, B., Harrington, D. and R. Presuhn, "An Architecture for Describing SNMP Management Frameworks", RFC 2571, April 1999.
[2] Rose, M. and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", STD 16, RFC 1155, May 1990.
[3] Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16, RFC 1212, March 1991.
[4] Rose, M., "A Convention for Defining Traps for use with the SNMP", RFC 1215, March 1991.
[5] 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.
[6] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999.
[7] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Conformance Statements for SMIv2", STD 58, RFC 2580, April 1999.
[8] Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple Network Management Protocol", STD 15, RFC 1157, May 1990.
[9] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Introduction to Community-based SNMPv2", RFC 1901, January 1996.
[10] 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.
[11] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)", RFC 2572, April 1999.
[12] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", RFC 2574, April 1999.
[13] 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.
[14] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC 2573, April 1999.
[15] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", RFC 2575, April 1999.
[16] Deering, S., "Host Extensions for IP Multicasting", STD 5, RFC 1112, August 1989.
[17] Fenner, W., "Internet Group Management Protocol, Version 2", RFC 2236, November 1997.
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