Network Working Group F. Kastenholz
Request for Comments: 1474 FTP Software, Inc.
June 1993
This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited.
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 describes managed objects used for managing the bridge Network Control Protocol [10] on subnetwork interfaces using the family of Point-to-Point Protocols.
1. The Network Management Framework
2. Objects
2.1 Format of Definitions
3. Overview
3.1 Object Selection Criteria
3.2 Structure of the PPP
3.3 MIB Groups
4. Definitions
5. Acknowledgements
6. Security Considerations
7. References
8. Author's Address
The Internet-standard Network Management Framework consists of three components. They are:
STD 16/RFC 1155 which defines the SMI, the mechanisms used for describing and naming objects for the purpose of management. STD 16/RFC 1212 defines a more concise description mechanism, which is
wholly consistent with the SMI.
STD 17/RFC 1213 which defines MIB-II, the core set of managed objects for the Internet suite of protocols.
STD 15/RFC 1157 which defines the SNMP, the protocol used for network access to managed objects.
The Framework permits new objects to be defined for the purpose of experimentation and evaluation.
Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the subset of Abstract Syntax Notation One (ASN.1) [3] defined in the SMI. In particular, each object type is named by an OBJECT IDENTIFIER, an administratively assigned name. The object type together with an object instance serves to uniquely identify a specific instantiation of the object. For human convenience, we often use a textual string, termed the descriptor, to refer to the object type.
Section 4 contains the specification of all object types contained in this MIB module. The object types are defined using the conventions defined in the SMI, as amended by the extensions specified in [5,6].
To be consistent with IAB directives and good engineering practice, an explicit attempt was made to keep this MIB as simple as possible. This was accomplished by applying the following criteria to objects proposed for inclusion:
(1) Require objects be essential for either fault or
configuration management. In particular, objects for
which the sole purpose was to debug implementations were
explicitly excluded from the MIB.
(2) Consider evidence of current use and/or utility.
(3) Limit the total number of objects.
(4) Exclude objects which are simply derivable from others in
this or other MIBs.
This section describes the basic model of PPP used in developing the PPP MIB. This information should be useful to the implementor in understanding some of the basic design decisions of the MIB.
The PPP is not one single protocol but a large family of protocols. Each of these is, in itself, a fairly complex protocol. The PPP protocols may be divided into three rough categories:
Control Protocols
The Control Protocols are used to control the operation of the
PPP. The Control Protocols include the Link Control Protocol
(LCP), the Password Authentication Protocol (PAP), the Link
Quality Report (LQR), and the Challenge Handshake Authentication
Protocol (CHAP).
Network Protocols
The Network Protocols are used to move the network traffic over
the PPP interface. A Network Protocol encapsulates the datagrams
of a specific higher-layer protocol that is using the PPP as a
data link. Note that within the context of PPP, the term "Network
Protocol" does not imply an OSI Layer-3 protocol; for instance,
there is a Bridging network protocol.
Network Control Protocols (NCPs)
The NCPs are used to control the operation of the Network
Protocols. Generally, each Network Protocol has its own Network
Control Protocol; thus, the IP Network Protocol has its IP Control
Protocol, the Bridging Network Protocol has its Bridging Network
Control Protocol and so on.
This document specifies the objects used in managing one of these protocols, namely the Bridge Network Control Protocol.
Objects in this MIB are arranged into several MIB groups. Each group is organized as a set of related objects.
These groups are the basic unit of conformance: if the semantics of a group are applicable to an implementation then all objects in the group must be implemented.
The PPP MIB is organized into several MIB Groups, including, but not limited to, the following groups:
This document specifies the following group:
The PPP Bridge Group
The PPP Bridge Group contains configuration, status, and control
variables that apply to the operation of Bridging over PPP.
Implementation of this group is mandatory for all implementations of PPP that support the Bridging over PPP.
PPP-BRIDGE-NCP-MIB DEFINITIONS ::= BEGIN
IMPORTS
Counter
FROM RFC1155-SMI
ifIndex
FROM RFC1213-MIB
OBJECT-TYPE
FROM RFC-1212
ppp
FROM PPP-LCP-MIB;
pppBridge OBJECT IDENTIFIER ::= { ppp 4 }
--
-- The PPP Bridge NCP Group.
-- Implementation of this group is mandatory for all
-- PPP implementations that support MAC Bridging over
-- PPP (RFC1220).
--
-- The following object reflect the values of the option
-- parameters used in the PPP Link Control Protocol
-- pppBridgeLocalToRemoteTinygramCompression
-- pppBridgeRemoteToLocalTinygramCompression
-- pppBridgeLocalToRemoteLanId
-- pppBridgeRemoteToLocalLanId
--
-- These values are not available until after the PPP Option
-- negotiation has completed, which is indicated by the link
-- reaching the open state (i.e. pppBridgeOperStatus is set to
-- opened).
--
-- Therefore, when pppBridgeOperStatus is not opened
-- the contents of these objects is undefined. The value
-- returned when accessing the objects is an implementation
-- dependent issue.
pppBridgeTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppBridgeEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Table containing the parameters and statistics
for the local PPP entity that are related to
the operation of Bridging over the PPP."
::= { pppBridge 1 }
pppBridgeEntry OBJECT-TYPE
SYNTAX PppBridgeEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Bridging information for a particular PPP
link."
INDEX { ifIndex }
::= { pppBridgeTable 1 }
PppBridgeEntry ::= SEQUENCE {
pppBridgeOperStatus
INTEGER,
pppBridgeLocalToRemoteTinygramCompression
INTEGER,
pppBridgeRemoteToLocalTinygramCompression
INTEGER,
pppBridgeLocalToRemoteLanId
INTEGER,
pppBridgeRemoteToLocalLanId
INTEGER
}
pppBridgeOperStatus OBJECT-TYPE
SYNTAX INTEGER {opened(1), not-opened(2)}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The operational status of the Bridge network
protocol. If the value of this object is up
then the finite state machine for the Bridge
network protocol has reached the Opened state."
::= { pppBridgeEntry 1 }
pppBridgeLocalToRemoteTinygramCompression OBJECT-TYPE
SYNTAX INTEGER { false(1), true(2) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the local node will perform
Tinygram Compression when sending packets to
the remote entity. If false then the local
entity will not perform Tinygram Compression.
If true then the local entity will perform
Tinygram Compression. The value of this object
is meaningful only when the link has reached
the open state (pppBridgeOperStatus is
opened)."
REFERENCE
"Section 6.7, Tinygram Compression Option, of
RFC1220"
::= { pppBridgeEntry 2 }
pppBridgeRemoteToLocalTinygramCompression OBJECT-TYPE
SYNTAX INTEGER { false(1), true(2) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"If false(1) then the remote entity is not
expected to perform Tinygram Compression. If
true then the remote entity is expected to
perform Tinygram Compression. The value of this
object is meaningful only when the link has
reached the open state (pppBridgeOperStatus is
opened)."
REFERENCE
"Section 6.7, Tinygram Compression Option, of
RFC1220"
::= { pppBridgeEntry 3 }
pppBridgeLocalToRemoteLanId OBJECT-TYPE
SYNTAX INTEGER { false(1), true(2) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the local node will include
the LAN Identification field in transmitted
packets or not. If false(1) then the local node
will not transmit this field, true(2) means
that the field will be transmitted. The value
of this object is meaningful only when the link
has reached the open state (pppBridgeOperStatus
is opened)."
REFERENCE
"Section 6.8, LAN Identification Option, of
RFC1220"
::= { pppBridgeEntry 4 }
pppBridgeRemoteToLocalLanId OBJECT-TYPE
SYNTAX INTEGER { false(1), true(2) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the remote node has
indicated that it will include the LAN
Identification field in transmitted packets or
not. If false(1) then the field will not be
transmitted, if true(2) then the field will be
transmitted. The value of this object is
meaningful only when the link has reached the
open state (pppBridgeOperStatus is opened)."
REFERENCE
"Section 6.8, LAN Identification Option, of
RFC1220"
::= { pppBridgeEntry 5 }
--
-- The PPP Bridge Configuration table
--
pppBridgeConfigTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppBridgeConfigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Table containing the parameters and statistics
for the local PPP entity that are related to the operation of Bridging over the PPP."
::= { pppBridge 2 }
pppBridgeConfigEntry OBJECT-TYPE
SYNTAX PppBridgeConfigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Bridging Configuration information for a
particular PPP link."
INDEX { ifIndex }
::= { pppBridgeConfigTable 1 }
PppBridgeConfigEntry ::= SEQUENCE {
pppBridgeConfigAdminStatus
INTEGER,
pppBridgeConfigTinygram
INTEGER,
pppBridgeConfigRingId
INTEGER,
pppBridgeConfigLineId
INTEGER,
pppBridgeConfigLanId
INTEGER
}
pppBridgeConfigAdminStatus OBJECT-TYPE
SYNTAX INTEGER { open(1), close(2) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The immediate desired status of the Bridging
network protocol. Setting this object to open
will inject an administrative open event into
the Bridging network protocol's finite state
machine. Setting this object to close will
inject an administrative close event into the
Bridging network protocol's finite state
machine."
::= { pppBridgeConfigEntry 1 }
pppBridgeConfigTinygram OBJECT-TYPE
SYNTAX INTEGER { false(1), true(2) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"If false then the local BNCP entity will not
initiate the Tinygram Compression Option
Negotiation. If true then the local BNCP entity
will initiate negotiation of this option."
REFERENCE
"Section 6.7, Tinygram Compression Option, of
RFC1220"
DEFVAL { true }
::= { pppBridgeConfigEntry 2 }
pppBridgeConfigRingId OBJECT-TYPE
SYNTAX INTEGER { false(1), true(2) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"If false then the local PPP Entity will not
initiate a Remote Ring Identification Option
negotiation. If true then the local PPP entity
will intiate this negotiation. This MIB object
is relevant only if the interface is for 802.5
Token Ring bridging."
REFERENCE
"Section 6.4, IEEE 802.5 Remote Ring
Identification Option, of RFC1220"
DEFVAL { false }
::= { pppBridgeConfigEntry 3 }
pppBridgeConfigLineId OBJECT-TYPE
SYNTAX INTEGER { false(1), true(2) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"If false then the local PPP Entity is not to
initiate a Line Identification Option
negotiation. If true then the local PPP entity
will intiate this negotiation. This MIB object
is relevant only if the interface is for 802.5
Token Ring bridging."
REFERENCE
"Section 6.5, IEEE 802.5 Line Identification
Option, of RFC1220"
DEFVAL { false }
::= { pppBridgeConfigEntry 4 }
pppBridgeConfigLanId OBJECT-TYPE
SYNTAX INTEGER { false(1), true(2) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"If false then the local BNCP entity will not
initiate the LAN Identification Option
Negotiation. If true then the local BNCP entity
will initiate negotiation of this option."
REFERENCE
"Section 6.8, LAN Identification Option, of
RFC1220"
DEFVAL { false }
::= { pppBridgeConfigEntry 5 }
--
-- The PPP Bridge Media Status Table
--
pppBridgeMediaTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppBridgeMediaEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Table identifying which MAC media types are
enabled for the Bridging NCPs."
::= { pppBridge 3 }
pppBridgeMediaEntry OBJECT-TYPE
SYNTAX PppBridgeMediaEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Status of a specific MAC Type for a specific
PPP Link."
INDEX { ifIndex, pppBridgeMediaMacType }
::= { pppBridgeMediaTable 1 }
PppBridgeMediaEntry ::= SEQUENCE {
pppBridgeMediaMacType
INTEGER,
pppBridgeMediaLocalStatus
INTEGER,
pppBridgeMediaRemoteStatus
INTEGER
}
pppBridgeMediaMacType OBJECT-TYPE
SYNTAX INTEGER(0..2147483647)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The MAC type for which this entry in the
pppBridgeMediaTable is providing status
information. Valid values for this object are
defined in Section 6.6 MAC Type Support
Selection of RFC1220 (Bridging Point-to-Point
Protocol)."
REFERENCE
"Section 6.6, MAC Type Support Selection, of
RFC1212."
::= { pppBridgeMediaEntry 1 }
pppBridgeMediaLocalStatus OBJECT-TYPE
SYNTAX INTEGER { accept(1), dont-accept(2) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the local PPP Bridging
Entity will accept packets of the protocol type
identified in pppBridgeMediaMacType on the PPP
link identified by ifIndex or not. If this
object is accept then any packets of the
indicated MAC type will be received and
properly processed. If this object is dont-
accept then received packets of the indicated
MAC type will not be properly processed."
REFERENCE
"Section 6.6, MAC Type Support Selection, of
RFC1212."
::= { pppBridgeMediaEntry 2 }
pppBridgeMediaRemoteStatus OBJECT-TYPE
SYNTAX INTEGER { accept(1), dont-accept(2) }
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the local PPP Bridging
Entity believes that the remote PPP Bridging
Entity will accept packets of the protocol type
identified in pppBridgeMediaMacType on the PPP
link identified by ifIndex or not."
REFERENCE
"Section 6.6, MAC Type Support Selection, of
RFC1212."
::= { pppBridgeMediaEntry 3 }
--
-- The PPP Bridge Media Configuration Table
--
pppBridgeMediaConfigTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppBridgeMediaConfigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Table identifying which MAC media types are
enabled for the Bridging NCPs."
::= { pppBridge 4 }
pppBridgeMediaConfigEntry OBJECT-TYPE
SYNTAX PppBridgeMediaConfigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Status of a specific MAC Type for a specific
PPP Link."
INDEX { ifIndex, pppBridgeMediaConfigMacType }
::= { pppBridgeMediaConfigTable 1 }
PppBridgeMediaConfigEntry ::= SEQUENCE {
pppBridgeMediaConfigMacType
INTEGER,
pppBridgeMediaConfigLocalStatus
INTEGER
}
pppBridgeMediaConfigMacType OBJECT-TYPE
SYNTAX INTEGER(0..2147483647)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The MAC type for which this entry in the
pppBridgeMediaConfigTable is providing status
information. Valid values for this object are
defined in Section 6.6 MAC Type Support
Selection of RFC1220 (Bridging Point-to-Point
Protocol)."
REFERENCE
"Section 6.6, MAC Type Support Selection, of
RFC1212."
::= { pppBridgeMediaConfigEntry 1 }
pppBridgeMediaConfigLocalStatus OBJECT-TYPE
SYNTAX INTEGER { accept(1), dont-accept(2) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
"Indicates whether the local PPP Bridging
Entity should accept packets of the protocol
type identified in pppBridgeMediaConfigMacType
on the PPP link identified by ifIndex or not.
Setting this object to the value dont-accept
has the affect of invalidating the
corresponding entry in the
pppBridgeMediaConfigTable object. It is an
implementation-specific matter as to whether
the agent removes an invalidated entry from the
table. Accordingly, management stations must be
prepared to receive tabular information from
agents that corresponds to entries not
currently in use. Changing this object will
have effect when the link is next restarted."
REFERENCE
"Section 6.6, MAC Type Support Selection, of
RFC1212."
::= { pppBridgeMediaConfigEntry 2 }
END
This document was produced by the PPP working group. In addition to the working group, the author wishes to thank the following individuals for their comments and contributions:
Bill Simpson -- Daydreamer
Glenn McGregor -- Merit
Jesse Walker -- DEC
Chris Gunner -- DEC
The PPP MIB affords the network operator the ability to configure and control the PPP links of a particular system, including the PPP authentication protocols. This represents a security risk.
These risks are addressed in the following manners:
(1) All variables which represent a significant security risk are placed in separate, optional, MIB Groups. As the MIB Group is the quantum of implementation within a MIB, the implementor of the MIB may elect not to implement these groups.
(2) The implementor may choose to implement the variables
which present a security risk so that they may not be
written, i.e., the variables are READ-ONLY. This method
still presents a security risk, and is not recommended,
in that the variables, specifically the PPP
Authentication Protocols' variables, may be easily read.
(3) Using SNMPv2, the operator can place the variables into MIB views which are protected in that the parties which have access to those MIB views use authentication and privacy protocols, or the operator may elect to make these views not accessible to any party. In order to facilitate this placement, all security-related variables are placed in separate MIB Tables. This eases the identification of the necessary MIB View Subtree.
[1] Rose M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based internets", STD 16, RFC 1155, Performance Systems International, Hughes LAN Systems, May 1990.
[2] McCloghrie K., and M. Rose, Editors, "Management Information Base for Network Management of TCP/IP-based internets", STD 17, RFC 1213, Performance Systems International, March 1991.
[3] Information processing systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), International Organization for Standardization, International Standard 8824, December 1987.
[4] Information processing systems - Open Systems Interconnection - Specification of Basic Encoding Rules for Abstract Notation One
(ASN.1), International Organization for Standardization, International Standard 8825, December 1987.
[5] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions", STD 16, RFC 1212, Performance Systems International, Hughes LAN Systems, March 1991.
[6] Rose, M., Editor, "A Convention for Defining Traps for use with the SNMP", RFC 1215, Performance Systems International, March 1991.
[7] McCloghrie, K., "Extensions to the Generic-Interface MIB", RFC 1229, Hughes LAN Systems, Inc., May 1991.
[8] Simpson, W., "The Point-to-Point Protocol for the Transmission of Multi-protocol Datagrams over Point-to-Point Links, RFC 1331, Daydreamer, May 1992.
[9] McGregor, G., "The PPP Internet Protocol Control Protocol", RFC 1332, Merit, May 1992.
[10] Baker, F., "Point-to-Point Protocol Extensions for Bridging", RFC 1220, ACC, April 1991.
[11] Lloyd, B., and W. Simpson, "PPP Authentication Protocols", RFC 1334, L&A, Daydreamer, October 1992.
[12] Simpson, W., "PPP Link Quality Monitoring", RFC 1333, Daydreamer, May 1992.
Frank Kastenholz
FTP Software, Inc.
2 High Street
North Andover, Mass 01845 USA
Phone: (508) 685-4000
EMail: kasten@ftp.com