RFC2922
Network Working Group A. Bierman Request for Comments: 2922 Cisco Systems, Inc. Category: Informational K. Jones
Nortel Networks
September 2000
Physical Topology MIB
Status of this Memo
This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2000). All Rights Reserved.
Abstract
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 managed objects used for managing physical topology identification and discovery.
Contents
- 1 The SNMP Network Management Framework
- 2 Overview
- 3 Topology Framework
- 4 Physical Topology MIB
- 5 Intellectual Property
- 6 Acknowledgements
- 7 References
- 8 Security Considerations
- 9 Authors' Addresses
The SNMP Network 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 readable information is not considered to change the semantics of the MIB.
Overview
There is a need for a standardized means of representing the physical network connections pertaining to a given management domain. The Physical Topology MIB (PTOPO-MIB) provides a standard way to identify connections between network ports and to discover network addresses of SNMP agents containing management information associated with each port.
A topology mechanism is used to discover the information required by the PTOPO-MIB. There is a need for a standardized topology mechanism to increase the likelihood of multi-vendor interoperability of such physical topology management information. The PTOPO-MIB does not, however, specify or restrict the discovery mechanism(s) used for an implementation of the PTOPO-MIB. Topology mechanisms exist for certain media types (such as FDDI) and proprietary mechanisms exist for other media such as shared media Ethernet, switched Ethernet, and Token Ring. Rather than specifying mechanisms for each type of technology, the PTOPO-MIB allows co-existence of multiple topology mechanisms. The required objects of the PTOPO-MIB define the core requirements for any topology mechanism.
The scope of the physical topology (PTOPO) mechanism is the identification of connections between two network ports. Network addresses of SNMP agents containing management information associated with each port can also be identified.
Terms
Some terms are used throughout this document:
Physical Topology
Physical topology represents the topology model for layer 1 of
the OSI stack - the physical layer. Physical topology consists
of identifying the devices on the network and how they are
physically interconnected. By definition of this document,
physical topology does not imply a physical relationship
between ports on the same device. Other means exist for
determining these relationships (e.g., Entity MIB RFC2737) exist for determining these relationships. Note that physical topology is independent of logical topology, which associates ports based on higher layer attributes, such as network layer address.
Chassis
A chassis is a physical component which contains other physical
components. It is identified by an entPhysicalEntry with an
entPhysicalClass value of 'chassis(3)' and an
entPhysicalContainedIn value of zero. A chassis identifier
consists of a globally unique SnmpAdminString.
Local Chassis
The particular chassis containing the SNMP agent implementing
the PTOPO MIB.
Port
A port is a physical component which can be connected to
another port through some medium. It is identified by an
entPhysicalEntry with an entPhysicalClass value of 'port(10)'.
A port identifier consists of an SnmpAdminString which must be
unique within the context of the chassis which contains the
port.
Connection Endpoint
A connection endpoint consists of a physical port, which is
contained within a single physical chassis.
Connection Endpoint Identifier
A connection endpoint is identified by a globally unique
chassis identifier and a port identifier unique within the
associated chassis.
Connection
A connection consists of two physical ports, and the attached
physical medium, configured for the purpose of transferring
network traffic between the ports. A connection is identified
by its endpoint identifiers.
Non-local Connection
A connection for which neither endpoint is located on the local
chassis.
Cloud
A cloud identifies a portion of the topology for which
insufficient information is known to completely infer the
interconnection of devices that make up that portion of the
topology.
Design Goals
Several factors influenced the design of this physical topology function:
- Simplicity
The physical topology discovery function should be as simple as
possible, exposing only the information needed to identify
connection endpoints and the SNMP agent(s) associated with each
connection endpoint.
- Completeness
At least one standard discovery protocol capable of supporting
the standard physical topology MIB must be defined. Multi-
vendor interoperability will not be achievable unless a simple
and extensible discovery protocol is available. However, the
PTOPO MIB should not specify or restrict the topology discovery
mechanisms an agent can use.
- No Functional Overlap
Existing standard MIBs should be utilized whenever possible.
Physical topology information is tightly coupled to
functionality found in the Interfaces MIB RFC2233 and Entity
MIB RFC2737. New physical topology MIB objects should not
duplicate these MIBs.
- Identifier Stability
Connection endpoint identifiers must be persistent (i.e. stable
across device reboots). Dynamic primary key objects like
ifIndex and entPhysicalIndex are not suitable for table indices
in a physical topology MIB that is replicated and distributed
throughout a managed system.
- Identifier Flexibility
Persistent string-based component identifiers should be
supported from many sources. Chassis identifiers may be found
in the Entity MIB RFC2737, and port identifiers may be found
in the Interfaces MIB RFC2233 or Entity MIB RFC2737.
- Partial Topology Support
Physical topology data for remote components may only be
partially available to an agent. An enumerated INTEGER
hierarchy of component identifier types allows for incomplete
physical connection identifier information to be substituted
with secondary information such as unicast source MAC address
or network address associated with a particular port. A PTOPO
Agent maintains information derived from the 'best' source of
information for each connection. If a 'better' identifier
source is detected, the PTOPO entries are updated accordingly.
It is an implementation specific matter whether a PTOPO agent
replaces 'old' entries or retains them, however an agent must
remove information known to be incorrect.
- Low Polling Impact
Physical topology polling should be minimized through
techniques such as TimeFiltered data tables (from RMON-2
RFC2021), and last-change notifications.
Topology Framework
This section describes the physical topology framework in detail.
Devices and Topology Agents
The network devices, along with their physical connectivity, make up the physical topology. Some of these devices (but maybe not all) provide management agents that report their local physical topology information to a manager via the physical topology MIB.
These devices include communication infrastructure devices, such as hubs, switches, and routers, as well as 'leaf' devices such as workstations, printers, and servers. Generally, user data passes through infrastructure devices while leaf devices are sources and sinks of data. Both types of devices may implement the physical topology MIB, although implementation within leaf devices is much less critical.
Each managed device collects physical topology information from the network, based on the topology mechanism(s) it is configured to use. The data represents this agent's local view of the physical network. Part of the topology data collected must include the identification of other local agents which may contain additional topology information. The definition of 'local' varies based on the topology mechanism or mechanisms being used.
Topology Mechanisms
A topology mechanism is a means, possibly requiring some sort of protocol, by which devices determine topology information. The topology mechanism must provide sufficient information to populate the MIB described later in this document.
Topology mechanisms can be active or passive. Active mechanisms require a device to send and receive topology protocol packets. These packets provide the device ID of the source of the packet and may also indicate out which port the packet was transmitted. When receiving these packets, devices typically are required to identify on which port that packet was received.
Passive mechanisms take advantage of data on the network to populate the topology MIB. By maintaining a list of device identifiers seen on each port of all devices in a network, it is possible to populate the PTOPO-MIB.
Many instances of a particular topology mechanism may be in use on a given network, and many different mechanisms may be employed. In some cases, multiple mechanisms may overlap across part of the physical topology with individual ports supporting more than one topology mechanism. In general, this simply allows the port to collect more robust topology information. Agents may need to be configured so that they know which mechanism(s) are in use on any given portion of the network.
Most topology mechanisms need to be bounded to a subset of the network to contain their impact on the network and limit the size of topology tables maintained by the agent. Topology mechanisms are often naturally bounded by the media on which they run (e.g. FDDI topology mechanism) or by routers in the network that intentionally block the mechanism from crossing into other parts of the network.
Future Considerations
While the framework presented here is focused on physical topology, it may well be that the topology mechanisms and MIB described could be extended to include logical topology information as well. That is not a focus of this memo.
Physical Topology MIB
This section describes and defines the Physical Topology MIB.
Persistent Identifiers
The PTOPO MIB utilizes non-volatile identifiers to distinguish individual chassis and port components. These identifiers are associated with external objects in order to relate topology information to the existing managed objects.
In particular, an object from the Entity MIB RFC2737 or Interfaces MIB RFC2233 can be used as the 'reference-point' for a connection component identifier.
The Physical Topology MIB uses two identifier types pertaining to the PTOPO MIB:
- globally unique chassis identifiers.
- port identifiers; unique only within the chassis which contains
the port.
Identifiers are stored as OCTET STRINGs, which are limited to 32 bytes in length, This supports flexible naming conventions and constrains the non-volatile storage requirements for an agent.
Relationship to Entity MIB
The first version of the Entity MIB RFC2037 allows the physical component inventory and hierarchy to be identified. However, this MIB does not provide persistent component identifiers, which are required for the PTOPO MIB. Therefore, version 2 of the Entity MIB RFC2737 is required to support that feature. Specifically, the entPhysicalAlias object is utilized as a persistent chassis identifier.
For agents implementing the PTOPO MIB, this new object must be used to represent the chassis identifier. Port identifiers can be based on the entPhysicalAlias object associated with the port, but only if the port is not represented as an interface in the ifXTable.
Implementation of the entPhysicalGroup RFC2737 and the entPhysicalAlias object RFC2737 are mandatory for SNMP agents which implement the PTOPO MIB. No other objects must be implemented from these MIBs to support the physical topology function.
Relationship to Interfaces MIB
The PTOPO MIB requires a persistent identifier for each port. The Interfaces MIB RFC2233 provides a standard mechanism for managing network interfaces. Unfortunately, not all ports which may be represented in the PTOPO MIB are also represented in the Interfaces MIB (e.g., repeater ports).
For agents which implement the PTOPO MIB, for each port also represented in the Interfaces MIB, the agent must use the associated ifAlias value for the port identifier. For each port not represented in the Interfaces MIB, the associated entPhysicalAlias value must be used for the port identifier. Note that the PTOPO MIB requires only minimal support from the Interfaces MIB. Specifically, the ' ifGeneralInformationGroup' level of conformance must be provided for each port also identified in the PTOPO MIB. The agent may choose to support these objects with read-only access, as specified in the conformance section of the Interfaces MIB.
Relationship to RMON-2 MIB
The RMON-2 MIB RFC2021 contains address mapping information which can be integrated with physical topology information. The physical ports identified in a physical topology MIB can be related to the MAC and network layer addresses found in the addressMapTable.
Relationship to Bridge MIB
The Bridge MIB RFC1493 contains information which may relate to physical ports represented in the ptopoConnTable. Entries in the dot1dBasePortTable and dot1dStpPortTable can by related to physical ports represented in the PTOPO MIB. Also, bridge port MAC addresses may be used as chassis and port identifiers in some situations.
Relationship to Repeater MIB
The Repeater MIB RFC2108 contains information which may relate to physical ports represented in the PTOPO MIB. Entries in the rptrPortTable and rptrMonitorPortTable can by related to physical ports represented in the ptopoConnTable. Entries in the rptrInfoTable and rptrMonTable can be related to repeater backplanes possibly represented in the ptopoConnTable.
MIB Structure
The PTOPO MIB contains three MIB object groups:
- ptopoData
Exposes physical topology data learned from discovery protocols
and/or manual configuration.
- ptopoGeneral
Contains general information regarding PTOPO MIB status.
- ptopoConfig
Contains configuration variables for the PTOPO MIB agent
function.
ptopoData Group
This group contains a single table to identity physical topology data.
The ptopoConnTable contains information about the connections learned or configured on behalf of the PTOPO MIB SNMP Agent.
ptopoGeneral Group
This group contains some scalar objects to report the status of the PTOPO MIB information currently known to the SNMP Agent. The global last change time, and table add and delete counters allow an NMS to set threshold alarms to trigger PTOPO polling.
ptopoConfig Group
This group contains tables to configure the behavior of the physical topology function. The transmission of ptopoLastChange notifications can be configured using the ptopoConfigTrapInterval scalar MIB object.
Physical Topology MIB Definitions
PTOPO-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
Integer32, Counter32, mib-2
FROM SNMPv2-SMI
TEXTUAL-CONVENTION, AutonomousType, RowStatus, TimeStamp, TruthValue
FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
FROM SNMPv2-CONF
TimeFilter
FROM RMON2-MIB
PhysicalIndex
FROM ENTITY-MIB
AddressFamilyNumbers
FROM IANA-ADDRESS-FAMILY-NUMBERS-MIB;
ptopoMIB MODULE-IDENTITY
LAST-UPDATED "200009210000Z"
ORGANIZATION "IETF; PTOPOMIB Working Group"
CONTACT-INFO
"PTOPOMIB WG Discussion:
[email protected]
Subscription:
[email protected]
msg body: [un]subscribe ptopomib
Andy Bierman
Cisco Systems Inc.
170 West Tasman Drive
San Jose, CA 95134
408-527-3711
[email protected]
Kendall S. Jones
Nortel Networks
4401 Great America Parkway
Santa Clara, CA 95054
408-495-7356
[email protected]"
DESCRIPTION
"The MIB module for physical topology information."
REVISION "200009210000Z"
DESCRIPTION
"Initial Version of the Physical Topology MIB. This version
published as RFC 2922."
::= { mib-2 79 }
ptopoMIBObjects OBJECT IDENTIFIER ::= { ptopoMIB 1 }
-- MIB groups ptopoData OBJECT IDENTIFIER ::= { ptopoMIBObjects 1 } ptopoGeneral OBJECT IDENTIFIER ::= { ptopoMIBObjects 2 } ptopoConfig OBJECT IDENTIFIER ::= { ptopoMIBObjects 3 }
-- textual conventions
PtopoGenAddr ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"The value of an address."
SYNTAX OCTET STRING (SIZE (0..20))
PtopoChassisIdType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"This TC describes the source of a chassis identifier.
The enumeration 'chasIdEntPhysicalAlias(1)' represents a
chassis identifier based on the value of entPhysicalAlias
for a chassis component (i.e., an entPhysicalClass value of
'chassis(3)').
The enumeration 'chasIdIfAlias(2)' represents a chassis
identifier based on the value of ifAlias for an interface
on the containing chassis.
The enumeration 'chasIdPortEntPhysicalAlias(3)' represents
a chassis identifier based on the value of entPhysicalAlias
for a port or backplane component (i.e., entPhysicalClass
value of 'port(10)' or 'backplane(4)'), within the
containing chassis.
The enumeration 'chasIdMacAddress(4)' represents a chassis
identifier based on the value of a unicast source MAC
address (encoded in network byte order and IEEE 802.3
canonical bit order), of a port on the containing chassis.
The enumeration 'chasIdPtopoGenAddr(5)' represents a
chassis identifier based on a network address, associated
with a particular chassis. The encoded address is actually
composed of two fields. The first field is a single octet,
representing the IANA AddressFamilyNumbers value for the
specific address type, and the second field is the
PtopoGenAddr address value."
SYNTAX INTEGER {
chasIdEntPhysicalAlias(1),
chasIdIfAlias(2),
chasIdPortEntPhysicalAlias(3),
chasIdMacAddress(4),
chasIdPtopoGenAddr(5)
}
PtopoChassisId ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"This TC describes the format of a chassis identifier
string. Objects of this type are always used with an
associated PtopoChassisIdType object, which identifies the
format of the particular PtopoChassisId object instance.
If the associated PtopoChassisIdType object has a value of
'chasIdEntPhysicalAlias(1)', then the octet string
identifies a particular instance of the entPhysicalAlias
object for a chassis component (i.e., an entPhysicalClass
value of 'chassis(3)').
If the associated PtopoChassisIdType object has a value of
'chasIdIfAlias(2)', then the octet string identifies a
particular instance of the ifAlias object for an interface
on the containing chassis.
If the associated PtopoChassisIdType object has a value of
'chasIdPortEntPhysicalAlias(3)', then the octet string
identifies a particular instance of the entPhysicalAlias
object for a port or backplane component within the
containing chassis.
If the associated PtopoChassisIdType object has a value of
'chasIdMacAddress(4)', then this string identifies a
particular unicast source MAC address (encoded in network
byte order and IEEE 802.3 canonical bit order), of a port on
the containing chassis.
If the associated PtopoChassisIdType object has a value of
'chasIdPtopoGenAddr(5)', then this string identifies a
particular network address, encoded in network byte order,
associated with one or more ports on the containing chassis.
The first octet contains the IANA Address Family Numbers
enumeration value for the specific address type, and octets
2 through N contain the PtopoGenAddr address value in
network byte order."
SYNTAX OCTET STRING (SIZE (1..32))
PtopoPortIdType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"This TC describes the source of a particular type of port
identifier used in the PTOPO MIB.
The enumeration 'portIdIfAlias(1)' represents a port
identifier based on the ifAlias MIB object.
The enumeration 'portIdPortEntPhysicalAlias(2)' represents a
port identifier based on the value of entPhysicalAlias for a
port or backplane component (i.e., entPhysicalClass value of
'port(10)' or 'backplane(4)'), within the containing
chassis.
The enumeration 'portIdMacAddr(3)' represents a port
identifier based on a unicast source MAC address, which has
been detected by the agent and associated with a particular
port.
The enumeration 'portIdPtopoGenAddr(4)' represents a port
identifier based on a network address, detected by the agent
and associated with a particular port."
SYNTAX INTEGER {
portIdIfAlias(1),
portIdEntPhysicalAlias(2),
portIdMacAddr(3),
portIdPtopoGenAddr(4)
}
PtopoPortId ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"This TC describes the format of a port identifier string.
Objects of this type are always used with an associated
PtopoPortIdType object, which identifies the format of the
particular PtopoPortId object instance.
If the associated PtopoPortIdType object has a value of
'portIdIfAlias(1)', then the octet string identifies a
particular instance of the ifAlias object.
If the associated PtopoPortIdType object has a value of
'portIdEntPhysicalAlias(2)', then the octet string
identifies a particular instance of the entPhysicalAlias
object for a port component (i.e., entPhysicalClass value of
'port(10)').
If the associated PtopoPortIdType object has a value of
'portIdMacAddr(3)', then this string identifies a particular
unicast source MAC address associated with the port.
If the associated PtopoPortIdType object has a value of
'portIdPtopoGenAddr(4)', then this string identifies a
network address associated with the port. The first octet
contains the IANA AddressFamilyNumbers enumeration value for
the specific address type, and octets 2 through N contain
the PtopoGenAddr address value in network byte order." SYNTAX OCTET STRING (SIZE (1..32))
PtopoAddrSeenState ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"This TC describes the state of address detection for a
particular type of port identifier used in the PTOPO MIB.
The enumeration 'notUsed(1)' represents an entry for which
the particular MIB object is not applicable to the remote
connection endpoint,
The enumeration 'unknown(2)' represents an entry for which
the particular address collection state is not known.
The enumeration 'oneAddr(3)' represents an entry for which
exactly one source address (of the type indicated by the
particular MIB object), has been detected.
The enumeration 'multiAddr(4)' represents an entry for
which more than one source address (of the type indicated by
the particular MIB object), has been detected.
An agent is expected to set the initial state of the
PtopoAddrSeenState to 'notUsed(1)' or 'unknown(2)'.
Note that the PTOPO MIB does not restrict or specify the
means in which the PtopoAddrSeenState is known to an agent.
In particular, an agent may detect this information through
configuration data, or some means other than directly
monitoring all port traffic."
SYNTAX INTEGER {
notUsed(1),
unknown(2),
oneAddr(3),
multiAddr(4)
}
-- *********************************************************** -- -- P T O P O D A T A G R O U P -- -- ***********************************************************
-- Connection Table
ptopoConnTable OBJECT-TYPE
SYNTAX SEQUENCE OF PtopoConnEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table contains one or more rows per physical network
connection known to this agent. The agent may wish to
ensure that only one ptopoConnEntry is present for each
local port, or it may choose to maintain multiple
ptopoConnEntries for the same local port.
Entries based on lower numbered identifier types are
preferred over higher numbered identifier types, i.e., lower
values of the ptopoConnRemoteChassisType and
ptopoConnRemotePortType objects."
::= { ptopoData 1 }
ptopoConnEntry OBJECT-TYPE
SYNTAX PtopoConnEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Information about a particular physical network connection.
Entries may be created and deleted in this table, either
manually or by the agent, if a physical topology discovery
process is active."
INDEX {
ptopoConnTimeMark,
ptopoConnLocalChassis,
ptopoConnLocalPort,
ptopoConnIndex
}
::= { ptopoConnTable 1 }
PtopoConnEntry ::= SEQUENCE {
ptopoConnTimeMark TimeFilter, ptopoConnLocalChassis PhysicalIndex, ptopoConnLocalPort PhysicalIndex, ptopoConnIndex Integer32, ptopoConnRemoteChassisType PtopoChassisIdType, ptopoConnRemoteChassis PtopoChassisId, ptopoConnRemotePortType PtopoPortIdType, ptopoConnRemotePort PtopoPortId, ptopoConnDiscAlgorithm AutonomousType, ptopoConnAgentNetAddrType AddressFamilyNumbers, ptopoConnAgentNetAddr PtopoGenAddr, ptopoConnMultiMacSASeen PtopoAddrSeenState, ptopoConnMultiNetSASeen PtopoAddrSeenState,
ptopoConnIsStatic TruthValue, ptopoConnLastVerifyTime TimeStamp, ptopoConnRowStatus RowStatus
}
ptopoConnTimeMark OBJECT-TYPE
SYNTAX TimeFilter
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A TimeFilter for this entry. See the TimeFilter textual
convention in RFC 2021 to see how this works."
::= { ptopoConnEntry 1 }
ptopoConnLocalChassis OBJECT-TYPE
SYNTAX PhysicalIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The entPhysicalIndex value used to identify the chassis
component associated with the local connection endpoint."
::= { ptopoConnEntry 2 }
ptopoConnLocalPort OBJECT-TYPE
SYNTAX PhysicalIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The entPhysicalIndex value used to identify the port
component associated with the local connection endpoint."
::= { ptopoConnEntry 3 }
ptopoConnIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This object represents an arbitrary local integer value
used by this agent to identify a particular connection
instance, unique only for the indicated local connection
endpoint.
A particular ptopoConnIndex value may be reused in the event
an entry is aged out and later re-learned with the same (or
different) remote chassis and port identifiers.
An agent is encouraged to assign monotonically increasing
index values to new entries, starting with one, after each
reboot. It is considered unlikely that the ptopoConnIndex
will wrap between reboots."
::= { ptopoConnEntry 4 }
ptopoConnRemoteChassisType OBJECT-TYPE
SYNTAX PtopoChassisIdType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The type of encoding used to identify the chassis
associated with the remote connection endpoint.
This object may not be modified if the associated
ptopoConnRowStatus object has a value of active(1)."
::= { ptopoConnEntry 5 }
ptopoConnRemoteChassis OBJECT-TYPE
SYNTAX PtopoChassisId
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The string value used to identify the chassis component
associated with the remote connection endpoint.
This object may not be modified if the associated
ptopoConnRowStatus object has a value of active(1)."
::= { ptopoConnEntry 6 }
ptopoConnRemotePortType OBJECT-TYPE
SYNTAX PtopoPortIdType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The type of port identifier encoding used in the associated
'ptopoConnRemotePort' object.
This object may not be modified if the associated
ptopoConnRowStatus object has a value of active(1)."
::= { ptopoConnEntry 7 }
ptopoConnRemotePort OBJECT-TYPE
SYNTAX PtopoPortId
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The string value used to identify the port component
associated with the remote connection endpoint.
This object may not be modified if the associated
ptopoConnRowStatus object has a value of active(1)."
::= { ptopoConnEntry 8 }
ptopoConnDiscAlgorithm OBJECT-TYPE
SYNTAX AutonomousType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An indication of the algorithm used to discover the
information contained in this conceptual row.
A value of ptopoDiscoveryLocal indicates this entry was
configured by the local agent, without use of a discovery
protocol.
A value of { 0 0 } indicates this entry was created manually
by an NMS via the associated RowStatus object. "
::= { ptopoConnEntry 9 }
ptopoConnAgentNetAddrType OBJECT-TYPE
SYNTAX AddressFamilyNumbers
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This network address type of the associated
ptopoConnNetAddr object, unless that object contains a zero
length string. In such a case, an NMS application should
ignore any returned value for this object.
This object may not be modified if the associated
ptopoConnRowStatus object has a value of active(1)."
::= { ptopoConnEntry 10 }
ptopoConnAgentNetAddr OBJECT-TYPE
SYNTAX PtopoGenAddr
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object identifies a network address which may be used
to reach an SNMP agent entity containing information for the
chassis and port components represented by the associated
'ptopoConnRemoteChassis' and 'ptopoConnRemotePort' objects.
If no such address is known, then this object shall contain
an empty string.
This object may not be modified if the associated
ptopoConnRowStatus object has a value of active(1)."
::= { ptopoConnEntry 11 }
ptopoConnMultiMacSASeen OBJECT-TYPE
SYNTAX PtopoAddrSeenState
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates if multiple unicast source MAC
addresses have been detected by the agent from the remote
connection endpoint, since the creation of this entry.
If this entry has an associated ptopoConnRemoteChassisType
and/or ptopoConnRemotePortType value other than
'portIdMacAddr(3)', then the value 'notUsed(1)' is returned.
Otherwise, one of the following conditions must be true:
If the agent has not yet detected any unicast source MAC
addresses from the remote port, then the value 'unknown(2)'
is returned.
If the agent has detected exactly one unicast source MAC
address from the remote port, then the value 'oneAddr(3)' is
returned.
If the agent has detected more than one unicast source MAC
address from the remote port, then the value 'multiAddr(4)'
is returned."
::= { ptopoConnEntry 12 }
ptopoConnMultiNetSASeen OBJECT-TYPE
SYNTAX PtopoAddrSeenState
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates if multiple network layer source
addresses have been detected by the agent from the remote
connection endpoint, since the creation of this entry.
If this entry has an associated ptopoConnRemoteChassisType
or ptopoConnRemotePortType value other than
'portIdGenAddr(4)' then the value 'notUsed(1)' is returned.
Otherwise, one of the following conditions must be true:
If the agent has not yet detected any network source
addresses of the appropriate type from the remote port, then
the value 'unknown(2)' is returned.
If the agent has detected exactly one network source address
of the appropriate type from the remote port, then the value
'oneAddr(3)' is returned.
If the agent has detected more than one network source
address (of the same appropriate type) from the remote port,
this the value 'multiAddr(4)' is returned."
::= { ptopoConnEntry 13 }
ptopoConnIsStatic OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object identifies static ptopoConnEntries. If this
object has the value 'true(1)', then this entry is not
subject to any age-out mechanisms implemented by the agent.
If this object has the value 'false(2)', then this entry is
subject to all age-out mechanisms implemented by the agent.
This object may not be modified if the associated
ptopoConnRowStatus object has a value of active(1)."
DEFVAL { false }
::= { ptopoConnEntry 14 }
ptopoConnLastVerifyTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"If the associated value of ptopoConnIsStatic is equal to
'false(2)', then this object contains the value of sysUpTime
at the time the conceptual row was last verified by the
agent, e.g., via reception of a topology protocol message,
pertaining to the associated remote chassis and port.
If the associated value of ptopoConnIsStatic is equal to
'true(1)', then this object shall contain the value of
sysUpTime at the time this entry was last activated (i.e.,
ptopoConnRowStatus set to 'active(1)')."
::= { ptopoConnEntry 15 }
ptopoConnRowStatus OBJECT-TYPE
SYNTAX RowStatus MAX-ACCESS read-create STATUS current DESCRIPTION
"The status of this conceptual row."
::= { ptopoConnEntry 16 }
-- *********************************************************** -- -- P T O P O G E N E R A L G R O U P -- -- ***********************************************************
-- last change time stamp for the whole MIB
ptopoLastChangeTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of sysUpTime at the time a conceptual row is
created, modified, or deleted in the ptopoConnTable.
An NMS can use this object to reduce polling of the
ptopoData group objects."
::= { ptopoGeneral 1 }
ptopoConnTabInserts OBJECT-TYPE
SYNTAX Counter32
UNITS "table entries"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of times an entry has been inserted into the
ptopoConnTable."
::= { ptopoGeneral 2 }
ptopoConnTabDeletes OBJECT-TYPE
SYNTAX Counter32 UNITS "table entries" MAX-ACCESS read-only STATUS current
DESCRIPTION
"The number of times an entry has been deleted from the
ptopoConnTable."
::= { ptopoGeneral 3 }
ptopoConnTabDrops OBJECT-TYPE
SYNTAX Counter32 UNITS "table entries" MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of times an entry would have been added to the
ptopoConnTable, (e.g., via information learned from a
topology protocol), but was not because of insufficient
resources."
::= { ptopoGeneral 4 }
ptopoConnTabAgeouts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of times an entry has been deleted from the
ptopoConnTable because the information timeliness interval
for that entry has expired."
::= { ptopoGeneral 5 }
-- *********************************************************** -- -- P T O P O C O N F I G G R O U P -- -- ***********************************************************
ptopoConfigTrapInterval OBJECT-TYPE
SYNTAX Integer32 (0 | 5..3600)
UNITS "seconds"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object controls the transmission of PTOPO
notifications.
If this object has a value of zero, then no
ptopoConfigChange notifications will be transmitted by the
agent.
If this object has a non-zero value, then the agent must not
generate more than one ptopoConfigChange trap-event in the
indicated period, where a 'trap-event' is the transmission
of a single notification PDU type to a list of notification
destinations. If additional configuration changes occur
within the indicated throttling period, then these trap-
events must be suppressed by the agent. An NMS should
periodically check the value of ptopoLastChangeTime to
detect any missed ptopoConfigChange trap-events, e.g. due to
throttling or transmission loss.
If notification transmission is enabled, the suggested
default throttling period is 60 seconds, but transmission
should be disabled by default.
If the agent is capable of storing non-volatile
configuration, then the value of this object must be
restored after a re-initialization of the management
system."
DEFVAL { 0 }
::= { ptopoConfig 1 }
ptopoConfigMaxHoldTime OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
UNITS "seconds"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object specifies the desired time interval for which
an agent will maintain dynamic ptopoConnEntries.
After the specified number of seconds since the last time an
entry was verified, in the absence of new verification
(e.g., receipt of a topology protocol message), the agent
shall remove the entry. Note that entries may not always be
removed immediately, but may possibly be removed at periodic
garbage collection intervals.
This object only affects dynamic ptopoConnEntries, i.e. for
which ptopoConnIsStatic equals 'false(2)'. Static entries
are not aged out.
Note that dynamic ptopoConnEntries may also be removed by
the agent due to the expired timeliness of learned topology
information (e.g., timeliness interval for a remote port
expires). The actual age-out interval for a given entry is
defined by the following formula:
age-out-time =
min(ptopoConfigMaxHoldTime, <entry-specific hold-time>)
where <entry-specific hold-time> is determined by the
discovery algorithm, and may be different for each entry."
DEFVAL { 300 }
::= { ptopoConfig 2 }
-- PTOPO MIB Notification Definitions ptopoMIBNotifications OBJECT IDENTIFIER ::= { ptopoMIB 2 } ptopoMIBTrapPrefix OBJECT IDENTIFIER ::=
{ ptopoMIBNotifications 0 }
ptopoConfigChange NOTIFICATION-TYPE
OBJECTS {
ptopoConnTabInserts,
ptopoConnTabDeletes,
ptopoConnTabDrops,
ptopoConnTabAgeouts
}
STATUS current
DESCRIPTION
"A ptopoConfigChange notification is sent when the value of
ptopoLastChangeTime changes. It can be utilized by an NMS to
trigger physical topology table maintenance polls.
Note that transmission of ptopoConfigChange notifications
are throttled by the agent, as specified by the
'ptopoConfigTrapInterval' object."
- = { ptopoMIBTrapPrefix 1 }
-- PTOPO Registration Points ptopoRegistrationPoints OBJECT IDENTIFIER ::= { ptopoMIB 3 }
-- values used with ptopoConnDiscAlgorithm object ptopoDiscoveryMechanisms OBJECT IDENTIFIER ::=
{ ptopoRegistrationPoints 1 }
ptopoDiscoveryLocal OBJECT IDENTIFIER ::=
{ ptopoDiscoveryMechanisms 1 }
-- conformance information ptopoConformance OBJECT IDENTIFIER ::= { ptopoMIB 4 }
ptopoCompliances OBJECT IDENTIFIER ::= { ptopoConformance 1 } ptopoGroups OBJECT IDENTIFIER ::= { ptopoConformance 2 }
-- compliance statements ptopoCompliance MODULE-COMPLIANCE STATUS current
DESCRIPTION
"The compliance statement for SNMP entities which implement
the PTOPO MIB."
MODULE -- this module
MANDATORY-GROUPS {
ptopoDataGroup,
ptopoGeneralGroup,
ptopoConfigGroup,
ptopoNotificationsGroup
}
::= { ptopoCompliances 1 }
-- MIB groupings ptopoDataGroup OBJECT-GROUP
OBJECTS {
ptopoConnRemoteChassisType,
ptopoConnRemoteChassis,
ptopoConnRemotePortType,
ptopoConnRemotePort,
ptopoConnDiscAlgorithm,
ptopoConnAgentNetAddrType,
ptopoConnAgentNetAddr,
ptopoConnMultiMacSASeen,
ptopoConnMultiNetSASeen,
ptopoConnIsStatic,
ptopoConnLastVerifyTime,
ptopoConnRowStatus
}
STATUS current
DESCRIPTION
"The collection of objects which are used to represent
physical topology information for which a single agent
provides management information.
This group is mandatory for all implementations of the PTOPO
MIB."
::= { ptopoGroups 1 }
ptopoGeneralGroup OBJECT-GROUP
OBJECTS {
ptopoLastChangeTime,
ptopoConnTabInserts,
ptopoConnTabDeletes,
ptopoConnTabDrops,
ptopoConnTabAgeouts
}
STATUS current
DESCRIPTION
"The collection of objects which are used to report the
general status of the PTOPO MIB implementation.
This group is mandatory for all agents which implement the
PTOPO MIB."
::= { ptopoGroups 2 }
ptopoConfigGroup OBJECT-GROUP
OBJECTS {
ptopoConfigTrapInterval,
ptopoConfigMaxHoldTime
}
STATUS current
DESCRIPTION
"The collection of objects which are used to configure the
PTOPO MIB implementation behavior.
This group is mandatory for agents which implement the PTOPO
MIB."
::= { ptopoGroups 3 }
ptopoNotificationsGroup NOTIFICATION-GROUP
NOTIFICATIONS {
ptopoConfigChange
}
STATUS current
DESCRIPTION
"The collection of notifications used to indicate PTOPO MIB
data consistency and general status information.
This group is mandatory for agents which implement the PTOPO
MIB."
::= { ptopoGroups 4 }
END
Intellectual Property
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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.
The IETF has been notified of intellectual property rights claimed in regard to some or all of the specification contained in this document. For more information consult the online list of claimed rights.
Acknowledgements
The PTOPO Discovery Protocol is a product of the IETF PTOPOMIB Working Group.
References
RFC1155 Rose, M. and K. McCloghrie, "Structure and Identification
of Management Information for TCP/IP-based Internets",
STD 16, RFC 1155, May 1990.
RFC1157 Case, J., Fedor, M., Schoffstall, M. and J. Davin,
"Simple Network Management Protocol", STD 15, RFC 1157, May 1990.
RFC1212 Rose, M. and K. McCloghrie, "Concise MIB Definitions",
STD 16, RFC 1212, March 1991.
RFC1215 Rose, M., "A Convention for Defining Traps for use with
the SNMP", RFC 1215, March 1991.
RFC1493 Decker, E., Langille, P., Rijsinghani, A. and K.
McCloghrie, "Definitions of Managed Objects for Bridges",
RFC 1493, July 1993.
RFC1700 Reynolds, J. and J. Postel, "Assigned Numbers", STD 2,
RFC 1700, October 1994.
RFC1901 Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Introduction to Community-based SNMPv2", January 1996.
RFC1902 Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Structure of Management Information for version 2 of the
Simple Network Management Protocol (SNMPv2)", RFC 1902,
January 1996.
RFC1903 Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Textual Conventions for version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC 1903, January 1996.
RFC1904 Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Conformance Statements for version 2 of the Simple
Network Management Protocol (SNMPv2)", RFC 1904, January
1996.
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.
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.
RFC2021 Waldbusser, S., "Remote Network Monitoring MIB (RMON-2)",
RFC 2021, January 1997.
RFC2037 McCloghrie, K. and A. Bierman, "Entity MIB using SMIv2",
RFC 2037, October 1996.
RFC2108 de Graaf, K., Romascanu, D., McMaster, D. and K.
McCloghrie, "Definitions of Managed Objects for IEEE
802.3 Repeater Devices using SMIv2", RFC 2108, February
1997.
RFC2233 McCloghrie, K. and F. Kastenholtz, "The Interfaces Group
MIB using SMIv2", RFC 2233, November 1997.
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.
RFC2571 Harrington, D., Presuhn, R. and B. Wijnen, "An
Architecture for Describing SNMP Management Frameworks",
RFC 2571, April 1999.
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.
RFC2573 Levi, D., Meyer, P. and B. Stewart, "SNMPv3
Applications", RFC 2573, 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.
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.
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.
RFC2737 McCloghrie, K. and A. Bierman, "Entity MIB (Version 2)",
RFC 2737, Cisco Systems, December 1999.
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.
There are a number of managed objects in this MIB that may contain sensitive information. These are:
read-create objects: ptopoConnRemoteChassisType
ptopoConnRemoteChassis ptopoConnRemotePortType
ptopoConnRemotePort ptopoConnAgentNetAddrType
ptopoConnAgentNetAddr ptopoConnIsStatic
ptopoConfigTrapInterval ptopoConfigMaxHoldTime
read-only objects: ptopoConnDiscAlgorithm
ptopoConnMultiMacSASeen ptopoConnMultiNetSASeen
ptopoConnLastVerifyTime ptopoLastChangeTime
notifications: ptopoConfigChange
These MIB objects expose information about the physical connectivity for a particular portion of a network.
A network administrator may also wish to inhibit transmission of any ptopoConfigChange notification by setting the ptopoConfigTrapInterval object to zero.
It is thus important to control even GET access to these objects and possibly to even encrypt the values of these object when sending them over the network via SNMP. Not all versions of SNMP provide features for such a secure environment.
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 RFC 2574 RFC2574 and the View- based Access Control Model RFC 2575 RFC2575 is recommended.
It is then a customer/user responsibility to ensure that the SNMP entity giving access to an instance of this 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/create/delete) them.
Authors' Addresses
Andy Bierman Cisco Systems 170 West Tasman Drive San Jose, CA USA 95134
Phone: +1 408-527-3711 EMail: [email protected]
Kendall S. Jones Nortel Networks 4401 Great America Parkway Santa Clara, CA USA 95054
Phone: +1 408-495-7356 EMail: [email protected]
10. Full Copyright Statement
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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.
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Acknowledgement
Funding for the RFC Editor function is currently provided by the Internet Society.
