Network Working Group F. Kastenholz

Network Working Group F. Kastenholz
Request for Comments: 1471 FTP Software, Inc.
June 1993

The Definitions of Managed Objects for
the Link Control Protocol of
the Point-to-Point Protocol

Status of this Memo

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.

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 describes managed objects used for managing the
Link Control Protocol and Link Quality Monitoring on subnetwork
interfaces that use the family of Point-to-Point Protocols [8, 9, 10,
11, & 12].

Table of Contents

1. The Network Management Framework ...................... 2
2. Objects ............................................... 2
2.1 Format of Definitions ................................ 2
3. Overview .............................................. 2
3.1 Object Selection Criteria ............................ 2
3.2 Structure of the PPP ................................. 3
3.3 MIB Groups ........................................... 4
3.4 Relationship to Interface and Interface Extensions
Groups ............................................... 5
4. Definitions ........................................... 6
4.1 PPP Link Group ....................................... 7
4.2 PPP LQR Group ........................................ 16
4.3 PPP LQR Extensions Group ............................. 21
4.4 PPP Tests ............................................ 22
4.4.1 PPP Echo Test ...................................... 22
4.4.2 PPP Discard Test ................................... 23
5. Acknowledgements ...................................... 23
6. Security Considerations ............................... 23
7. References ............................................ 24
8. Author's Address ...................................... 25

Kastenholz [Page 1]

RFC 1471 PPP/LCP MIB June 1993

1. The Network Management Framework

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.

2. Objects

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.

2.1. Format of Definitions

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].

3. Overview

3.1. Object Selection Criteria

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

Kastenholz [Page 2]

RFC 1471 PPP/LCP MIB June 1993

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.

3.2. Structure of the PPP

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 Link Control Protocol and Link Quality
Monitoring Protocol.

Kastenholz [Page 3]

RFC 1471 PPP/LCP MIB June 1993

3.3. MIB Groups

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:

o The PPP Link Group
o The PPP LQR Group
o The PPP LQR Extensions Group
o The PPP IP Group
o The PPP Bridge Group
o The PPP Security Group

This document specifies the following groups:

The PPP Link Group
This group represents the lowest "level" of the PPP protocol.

This group contains two tables, one containing status information
and the other configuration information. The configuration table
is split off of the status so that it may be placed in a separate
MIB View for security purposes.

Implementation of this group is mandatory for all PPP
implementations.

The PPP LQR Group
This group provides the basic MIB variables that apply to the PPP
LQR Protocol. This group provides MIB access to the information
required for LQR processing. This group contains two tables, one
containing status information and the other configuration
information. The configuration table is split off of the status
so that it may be placed in a separate MIB View for security
purposes.

Implementation of the PPP LQR Group is mandatory for all PPP
implementations that implement LQR.

The PPP LQR Extensions Group
The PPP LQR Extensions group contains the most recently received
LQR packet, as well as the "save" fields that are "logically
appended" [12] to received LQR packets. This is done in order to

Kastenholz [Page 4]

RFC 1471 PPP/LCP MIB June 1993

facilitate external implementations of the Link Quality Monitoring
policies.

It is not practical to examine the relevant MIB objects which are
used to generate LQR packets since LQR policies may require
synchronization of the values of all data used to determine Link
Quality; i.e., the values of the relevant counters must all be
taken at the same instant in time. Thus, by recording the last
received LQR packet, a synchronized record of the relevant data is
available.

As this information may not be efficiently maintained on all PPP
implementations, implementation of this group is optional.

3.4. Relationship to Interface and Interface Extensions
Groups

The PPP Mib is a medium-specific extension to the standard MIB-2
interface group [2] and to the Interface Extensions MIB [7]. This
section discusses certain components of these groups when the
interface is a PPP interface.

The PPP interface represents a single interface in the sense used in
[2] and thus has a single entry in the ifTable.

Furthermore, the PPP interface may be operating over a lower layer
hardware interface (such as an RS-232 port). It is important to
capture the relationship between the PPP interface and the lower-
layer interface over which it operates. This MIB presumes that the
lower-layer interface has an ifEntry associated with it. The lower-
layer ifEntry is identified via the pppLinkStatusPhysicalIndex
object, which contains the value of ifIndex for the lower-layer
ifEntry.

For example, suppose that you run PPP over a RS-232 port. This would
use two entries in the ifTable. Let's suppose that entry number 123
is for the PPP "interface" and entry number 987 is for the RS-232
port. So, ifSpecific.123 would contain the ppp OBJECT IDENTIFIER,
pppLinkStatusPhysicalIndex.123 would contain 987, and ifSpecific.987
would contain the rs_232 OBJECT IDENTIFIER (or whatever it is).

All PPP packets are defined in [8] as being broadcast packets. Thus,
the packets are counted as non-unicast packets in the ifTable
(ifInNUcastPkts and ifOutNUCastPkts) and as broadcasts in the
ifExtnsTable (ifExtnsBroadcastsReceivedOks and
ifExtnsBroadcastsTransmittedOks).

Kastenholz [Page 5]

RFC 1471 PPP/LCP MIB June 1993

ifSpecific
Contains the OBJECT IDENTIFIER ppp.

ifAdminStatus
Setting this object to up will inject an administrative open event
into the LCP's finite state machine. Setting this object to down
will inject an administrative close event into the LCP's finite
state machine.

The use of the testing value is beyond the scope of this document.

ifOperStatus
Represents the state of the LCP Finite State Machine. If the
Finite State Machine is in the Opened state then the value of
ifOperStatus is up, otherwise the value of ifOperStatus is down.

The meaning of the testing value is beyond the scope of this
document.

Per the SNMP Protocol Specification [13], the linkUp and linkDown
traps apply to the PPP Protocol entity. When the LCP's Finite State
Machine attains the Opened state, a linkUp trap should be sent. When
the Finite State Machine leaves the Opened state, a linkDown trap
should be sent.

Some tests for the link are defined in this document. Execution of
these tests does not place the link's ifOperStatus in the testing
state as these tests do not prevent normal data transmission from
occuring over the link.

4. Definitions

PPP-LCP-MIB DEFINITIONS ::= BEGIN

IMPORTS
Counter
FROM RFC1155-SMI
ifIndex, transmission
FROM RFC1213-MIB
OBJECT-TYPE
FROM RFC-1212;

-- PPP MIB

ppp OBJECT IDENTIFIER ::= { transmission 23 }

pppLcp OBJECT IDENTIFIER ::= { ppp 1 }

Kastenholz [Page 6]

RFC 1471 PPP/LCP MIB June 1993

-- The individual groups within the PPP-LCP-MIB

pppLink OBJECT IDENTIFIER ::= { pppLcp 1 }
pppLqr OBJECT IDENTIFIER ::= { pppLcp 2 }
pppTests OBJECT IDENTIFIER ::= { pppLcp 3 }

-- 4.1. PPP Link Group

--
-- The PPP Link Group. Implementation of this
-- group is mandatory for all PPP entities.
--

-- The following object reflect the values of the option
-- parameters used in the PPP Link Control Protocol
-- pppLinkStatusLocalMRU
-- pppLinkStatusRemoteMRU
-- pppLinkStatusLocalToPeerACCMap
-- pppLinkStatusPeerToLocalACCMap
-- pppLinkStatusLocalToRemoteProtocolCompression
-- pppLinkStatusRemoteToLocalProtocolCompression
-- pppLinkStatusLocalToRemoteACCompression
-- pppLinkStatusRemoteToLocalACCompression
-- pppLinkStatusTransmitFcsSize
-- pppLinkStatusReceiveFcsSize
--
-- 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., ifOperStatus is set to
-- up).
--
-- Therefore, when ifOperStatus is not up
-- the contents of these objects is undefined. The value
-- returned when accessing the objects is an implementation
-- dependent issue.

pppLinkStatusTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppLinkStatusEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A table containing PPP-link specific variables
for this PPP implementation."
::= { pppLink 1 }

Kastenholz [Page 7]

RFC 1471 PPP/LCP MIB June 1993

pppLinkStatusEntry OBJECT-TYPE
SYNTAX PppLinkStatusEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Management information about a particular PPP
Link."
INDEX { ifIndex }
::= { pppLinkStatusTable 1 }

PppLinkStatusEntry ::= SEQUENCE {
pppLinkStatusPhysicalIndex
INTEGER,
pppLinkStatusBadAddresses
Counter,
pppLinkStatusBadControls
Counter,
pppLinkStatusPacketTooLongs
Counter,
pppLinkStatusBadFCSs
Counter,
pppLinkStatusLocalMRU
INTEGER,
pppLinkStatusRemoteMRU
INTEGER,
pppLinkStatusLocalToPeerACCMap
OCTET STRING,
pppLinkStatusPeerToLocalACCMap
OCTET STRING,
pppLinkStatusLocalToRemoteProtocolCompression
INTEGER,
pppLinkStatusRemoteToLocalProtocolCompression
INTEGER,
pppLinkStatusLocalToRemoteACCompression
INTEGER,
pppLinkStatusRemoteToLocalACCompression
INTEGER,
pppLinkStatusTransmitFcsSize
INTEGER,
pppLinkStatusReceiveFcsSize
INTEGER
}
pppLinkStatusPhysicalIndex OBJECT-TYPE
SYNTAX INTEGER(0..2147483647)
ACCESS read-only
STATUS mandatory
DESCRIPTION

Kastenholz [Page 8]

RFC 1471 PPP/LCP MIB June 1993

"The value of ifIndex that identifies the
lower-level interface over which this PPP Link
is operating. This interface would usually be
an HDLC or RS-232 type of interface. If there
is no lower-layer interface element, or there
is no ifEntry for the element, or the element
can not be identified, then the value of this
object is 0. For example, suppose that PPP is
operating over a serial port. This would use
two entries in the ifTable. The PPP could be
running over `interface' number 123 and the
serial port could be running over `interface'
number 987. Therefore, ifSpecific.123 would
contain the OBJECT IDENTIFIER ppp
pppLinkStatusPhysicalIndex.123 would contain
987, and ifSpecific.987 would contain the
OBJECT IDENTIFIER for the serial-port's media-
specific MIB."
::= { pppLinkStatusEntry 1 }

pppLinkStatusBadAddresses OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of packets received with an
incorrect Address Field. This counter is a
component of the ifInErrors variable that is
associated with the interface that represents
this PPP Link."
REFERENCE
"Section 3.1, Address Field, of RFC1331."
::= { pppLinkStatusEntry 2 }

pppLinkStatusBadControls OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of packets received on this link
with an incorrect Control Field. This counter
is a component of the ifInErrors variable that
is associated with the interface that
represents this PPP Link."
REFERENCE
"Section 3.1, Control Field, of RFC1331."

Kastenholz [Page 9]

RFC 1471 PPP/LCP MIB June 1993

::= { pppLinkStatusEntry 3 }

pppLinkStatusPacketTooLongs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of received packets that have been
discarded because their length exceeded the
MRU. This counter is a component of the
ifInErrors variable that is associated with the
interface that represents this PPP Link. NOTE,
packets which are longer than the MRU but which
are successfully received and processed are NOT
included in this count."
::= { pppLinkStatusEntry 4 }

pppLinkStatusBadFCSs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of received packets that have been
discarded due to having an incorrect FCS. This
counter is a component of the ifInErrors
variable that is associated with the interface
that represents this PPP Link."
::= { pppLinkStatusEntry 5 }

pppLinkStatusLocalMRU OBJECT-TYPE
SYNTAX INTEGER(1..2147483648)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current value of the MRU for the local PPP
Entity. This value is the MRU that the remote
entity is using when sending packets to the
local PPP entity. The value of this object is
meaningful only when the link has reached the
open state (ifOperStatus is up)."
::= { pppLinkStatusEntry 6 }

pppLinkStatusRemoteMRU OBJECT-TYPE
SYNTAX INTEGER(1..2147483648)

Kastenholz [Page 10]

RFC 1471 PPP/LCP MIB June 1993

ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current value of the MRU for the remote
PPP Entity. This value is the MRU that the
local entity is using when sending packets to
the remote PPP entity. The value of this object
is meaningful only when the link has reached
the open state (ifOperStatus is up)."
::= { pppLinkStatusEntry 7 }

pppLinkStatusLocalToPeerACCMap OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (4))
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current value of the ACC Map used for
sending packets from the local PPP entity to
the remote PPP entity. The value of this object
is meaningful only when the link has reached
the open state (ifOperStatus is up)."
::= { pppLinkStatusEntry 8 }

pppLinkStatusPeerToLocalACCMap OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (4))
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The ACC Map used by the remote PPP entity when
transmitting packets to the local PPP entity.
The value of this object is meaningful only
when the link has reached the open state
(ifOperStatus is up)."
::= { pppLinkStatusEntry 9 }

pppLinkStatusLocalToRemoteProtocolCompression
OBJECT-TYPE
SYNTAX INTEGER {
enabled(1),
disabled(2)
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the local PPP entity will

Kastenholz [Page 11]

RFC 1471 PPP/LCP MIB June 1993

use Protocol Compression when transmitting
packets to the remote PPP entity. The value of
this object is meaningful only when the link
has reached the open state (ifOperStatus is
up)."
::= { pppLinkStatusEntry 10 }

pppLinkStatusRemoteToLocalProtocolCompression
OBJECT-TYPE
SYNTAX INTEGER {
enabled(1),
disabled(2)
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the remote PPP entity will
use Protocol Compression when transmitting
packets to the local PPP entity. The value of
this object is meaningful only when the link
has reached the open state (ifOperStatus is
up)."
::= { pppLinkStatusEntry 11 }

pppLinkStatusLocalToRemoteACCompression OBJECT-TYPE
SYNTAX INTEGER {
enabled(1),
disabled(2)
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the local PPP entity will
use Address and Control Compression when
transmitting packets to the remote PPP entity.
The value of this object is meaningful only
when the link has reached the open state
(ifOperStatus is up)."
::= { pppLinkStatusEntry 12 }

pppLinkStatusRemoteToLocalACCompression OBJECT-TYPE
SYNTAX INTEGER {
enabled(1),
disabled(2)
}

Kastenholz [Page 12]

RFC 1471 PPP/LCP MIB June 1993

ACCESS read-only
STATUS mandatory
DESCRIPTION
"Indicates whether the remote PPP entity will
use Address and Control Compression when
transmitting packets to the local PPP entity.
The value of this object is meaningful only
when the link has reached the open state
(ifOperStatus is up)."
::= { pppLinkStatusEntry 13 }

pppLinkStatusTransmitFcsSize OBJECT-TYPE
SYNTAX INTEGER (0..128)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The size of the Frame Check Sequence (FCS) in
bits that the local node will generate when
sending packets to the remote node. The value
of this object is meaningful only when the link
has reached the open state (ifOperStatus is
up)."
::= { pppLinkStatusEntry 14 }

pppLinkStatusReceiveFcsSize OBJECT-TYPE
SYNTAX INTEGER (0..128)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The size of the Frame Check Sequence (FCS) in
bits that the remote node will generate when
sending packets to the local node. The value of
this object is meaningful only when the link
has reached the open state (ifOperStatus is
up)."
::= { pppLinkStatusEntry 15 }

pppLinkConfigTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppLinkConfigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A table containing the LCP configuration
parameters for this PPP Link. These variables
represent the initial configuration of the PPP

Kastenholz [Page 13]

RFC 1471 PPP/LCP MIB June 1993

Link. The actual values of the parameters may
be changed when the link is brought up via the
LCP options negotiation mechanism."
::= { pppLink 2 }

pppLinkConfigEntry OBJECT-TYPE
SYNTAX PppLinkConfigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Configuration information about a particular
PPP Link."
INDEX { ifIndex }
::= { pppLinkConfigTable 1 }

PppLinkConfigEntry ::= SEQUENCE {
pppLinkConfigInitialMRU
INTEGER,
pppLinkConfigReceiveACCMap
OCTET STRING,
pppLinkConfigTransmitACCMap
OCTET STRING,
pppLinkConfigMagicNumber
INTEGER,
pppLinkConfigFcsSize
INTEGER
}

pppLinkConfigInitialMRU OBJECT-TYPE
SYNTAX INTEGER(0..2147483647)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The initial Maximum Receive Unit (MRU) that
the local PPP entity will advertise to the
remote entity. If the value of this variable is
0 then the local PPP entity will not advertise
any MRU to the remote entity and the default
MRU will be assumed. Changing this object will
have effect when the link is next restarted."
REFERENCE
"Section 7.2, Maximum Receive Unit of RFC1331."
DEFVAL { 1500 }
::= { pppLinkConfigEntry 1 }

Kastenholz [Page 14]

RFC 1471 PPP/LCP MIB June 1993

pppLinkConfigReceiveACCMap OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (4))
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The Asynchronous-Control-Character-Map (ACC)
that the local PPP entity requires for use on
its receive side. In effect, this is the ACC
Map that is required in order to ensure that
the local modem will successfully receive all
characters. The actual ACC map used on the
receive side of the link will be a combination
of the local node's pppLinkConfigReceiveACCMap
and the remote node's
pppLinkConfigTransmitACCMap. Changing this
object will have effect when the link is next
restarted."
REFERENCE
"Section 7.3, page 4, Async-Control-Character-
Map of RFC1331."
DEFVAL { 'ffffffff'h }
::= { pppLinkConfigEntry 2 }

pppLinkConfigTransmitACCMap OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (4))
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The Asynchronous-Control-Character-Map (ACC)
that the local PPP entity requires for use on
its transmit side. In effect, this is the ACC
Map that is required in order to ensure that
all characters can be successfully transmitted
through the local modem. The actual ACC map
used on the transmit side of the link will be a
combination of the local node's
pppLinkConfigTransmitACCMap and the remote
node's pppLinkConfigReceiveACCMap. Changing
this object will have effect when the link is
next restarted."
REFERENCE
"Section 7.3, page 4, Async-Control-Character-
Map of RFC1331."
DEFVAL { 'ffffffff'h }
::= { pppLinkConfigEntry 3 }

Kastenholz [Page 15]

RFC 1471 PPP/LCP MIB June 1993

pppLinkConfigMagicNumber OBJECT-TYPE
SYNTAX INTEGER {false (1), true (2)}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"If true(2) then the local node will attempt to
perform Magic Number negotiation with the
remote node. If false(1) then this negotiation
is not performed. In any event, the local node
will comply with any magic number negotiations
attempted by the remote node, per the PPP
specification. Changing this object will have
effect when the link is next restarted."
REFERENCE
"Section 7.6, Magic Number, of RFC1331."
DEFVAL { false }
::= { pppLinkConfigEntry 4 }

pppLinkConfigFcsSize OBJECT-TYPE
SYNTAX INTEGER (0..128)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The size of the FCS, in bits, the local node
will attempt to negotiate for use with the
remote node. Regardless of the value of this
object, the local node will comply with any FCS
size negotiations initiated by the remote node,
per the PPP specification. Changing this object
will have effect when the link is next
restarted."
DEFVAL { 16 }
::= { pppLinkConfigEntry 5 }

-- 4.2. PPP LQR Group

--
-- The PPP LQR Group.
-- Implementation of this group is mandatory for all
-- PPP implementations that implement LQR.
--

pppLqrTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppLqrEntry
ACCESS not-accessible

Kastenholz [Page 16]

RFC 1471 PPP/LCP MIB June 1993

STATUS mandatory
DESCRIPTION
"Table containing the LQR parameters and
statistics for the local PPP entity."
::= { pppLqr 1 }

pppLqrEntry OBJECT-TYPE
SYNTAX PppLqrEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"LQR information for a particular PPP link. A
PPP link will have an entry in this table if
and only if LQR Quality Monitoring has been
successfully negotiated for said link."
INDEX { ifIndex }
::= { pppLqrTable 1 }

PppLqrEntry ::= SEQUENCE {
pppLqrQuality
INTEGER,
pppLqrInGoodOctets
Counter,
pppLqrLocalPeriod
INTEGER,
pppLqrRemotePeriod
INTEGER,
pppLqrOutLQRs
Counter,
pppLqrInLQRs
Counter
}

pppLqrQuality OBJECT-TYPE
SYNTAX INTEGER {
good(1),
bad(2),
not-determined(3)
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current quality of the link as declared by
the local PPP entity's Link-Quality Management
modules. No effort is made to define good or
bad, nor the policy used to determine it. The

Kastenholz [Page 17]

RFC 1471 PPP/LCP MIB June 1993

not-determined value indicates that the entity
does not actually evaluate the link's quality.
This value is used to disambiguate the
`determined to be good' case from the `no
determination made and presumed to be good'
case."
::= { pppLqrEntry 1 }

pppLqrInGoodOctets OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The LQR InGoodOctets counter for this link."
REFERENCE
"Section 2.2, Counters, of RFC1333."
::= { pppLqrEntry 2 }

pppLqrLocalPeriod OBJECT-TYPE
SYNTAX INTEGER(1..2147483648)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The LQR reporting period, in hundredths of a
second that is in effect for the local PPP
entity."
REFERENCE
"Section 2.5, Configuration Option Format, of
RFC1333."
::= { pppLqrEntry 3 }

pppLqrRemotePeriod OBJECT-TYPE
SYNTAX INTEGER(1..2147483648)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The LQR reporting period, in hundredths of a
second, that is in effect for the remote PPP
entity."
REFERENCE
"Section 2.5, Configuration Option Format, of
RFC1333."
::= { pppLqrEntry 4 }

Kastenholz [Page 18]

RFC 1471 PPP/LCP MIB June 1993

pppLqrOutLQRs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of the OutLQRs counter on the local
node for the link identified by ifIndex."
REFERENCE
"Section 2.2, Counters, of RFC1333."
::= { pppLqrEntry 5 }

pppLqrInLQRs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of the InLQRs counter on the local
node for the link identified by ifIndex."
REFERENCE
"Section 2.2, Counters, of RFC1333."
::= { pppLqrEntry 6 }

--
-- The PPP LQR Configuration table.
--

pppLqrConfigTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppLqrConfigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Table containing the LQR Configuration
parameters for the local PPP entity."
::= { pppLqr 2 }

pppLqrConfigEntry OBJECT-TYPE
SYNTAX PppLqrConfigEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"LQR configuration information for a particular
PPP link."
INDEX { ifIndex }
::= { pppLqrConfigTable 1 }

Kastenholz [Page 19]

RFC 1471 PPP/LCP MIB June 1993

PppLqrConfigEntry ::= SEQUENCE {
pppLqrConfigPeriod
INTEGER,
pppLqrConfigStatus
INTEGER
}

pppLqrConfigPeriod OBJECT-TYPE
SYNTAX INTEGER(0..2147483647)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The LQR Reporting Period that the local PPP
entity will attempt to negotiate with the
remote entity, in units of hundredths of a
second. Changing this object will have effect
when the link is next restarted."
REFERENCE
"Section 2.5, Configuration Option Format, of
RFC1333."
DEFVAL { 0 }
::= { pppLqrConfigEntry 1 }

pppLqrConfigStatus OBJECT-TYPE
SYNTAX INTEGER {disabled (1), enabled (2)}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"If enabled(2) then the local node will attempt
to perform LQR negotiation with the remote
node. If disabled(1) then this negotiation is
not performed. In any event, the local node
will comply with any magic number negotiations
attempted by the remote node, per the PPP
specification. Changing this object will have
effect when the link is next restarted.
Setting this object to the value disabled(1)
has the effect of invalidating the
corresponding entry in the pppLqrConfigTable
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."
REFERENCE
"Section 7.6, Magic Number, of RFC1331."

Kastenholz [Page 20]

RFC 1471 PPP/LCP MIB June 1993

DEFVAL { enabled }
::= { pppLqrConfigEntry 2 }

-- 4.3. PPP LQR Extensions Group

--
-- The PPP LQR Extensions Group.
-- Implementation of this group is optional.
--
-- The intent of this group is to allow external
-- implementation of the policy mechanisms that
-- are used to declare a link to be "bad" or not.
--
-- It is not practical to examine the MIB objects
-- which are used to generate LQR packets since
-- LQR policies tend to require synchronization of
-- the values of all data used to determine Link
-- Quality; i.e. the values of the relevant counters
-- must all be taken at the same instant in time.
--

pppLqrExtnsTable OBJECT-TYPE
SYNTAX SEQUENCE OF PppLqrExtnsEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Table containing additional LQR information
for the local PPP entity."
::= { pppLqr 3 }

pppLqrExtnsEntry OBJECT-TYPE
SYNTAX PppLqrExtnsEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Extended LQR information for a particular PPP
link. Assuming that this group has been
implemented, a PPP link will have an entry in
this table if and only if LQR Quality
Monitoring has been successfully negotiated for
said link."
INDEX { ifIndex }
::= { pppLqrExtnsTable 1 }

PppLqrExtnsEntry ::= SEQUENCE {

Kastenholz [Page 21]

RFC 1471 PPP/LCP MIB June 1993

pppLqrExtnsLastReceivedLqrPacket
OCTET STRING(SIZE(68))
}

pppLqrExtnsLastReceivedLqrPacket OBJECT-TYPE
SYNTAX OCTET STRING(SIZE(68))
ACCESS read-only
STATUS mandatory
DESCRIPTION
"This object contains the most recently
received LQR packet. The format of the packet
is as described in the LQM Protocol
specificiation. All fields of the packet,
including the `save' fields, are stored in this
object.

The LQR packet is stored in network byte order.
The LAP-B and PPP headers are not stored in
this object; the first four octets of this
variable contain the Magic-Number field, the
second four octets contain the LastOutLQRs
field and so on. The last four octets of this
object contain the SaveInOctets field of the
LQR packet."
REFERENCE
"Section 2.6, Packet Format, of RFC1333"
::= { pppLqrExtnsEntry 1 }

-- 4.4. PPP Tests

-- The extensions to the interface table in RFC1229 define a
-- table through which the network manager can instruct the
-- managed object to perform various tests of the interface. This
-- is the ifExtnsTestTable.

-- The PPP MIB defines two such tests.

-- 4.4.1. PPP Echo Test

-- The PPP Echo Test is defined as

pppEchoTest OBJECT IDENTIFIER ::= { pppTests 1 }

-- Invoking this test causes a PPP Echo Packet to be sent on the
-- line. ifExtnsTestResult returns success(2) if the echo
-- response came back properly. It returns failed(7) if the
-- response did not properly return. The definition of "proper"

Kastenholz [Page 22]

RFC 1471 PPP/LCP MIB June 1993

-- in this context is left to the discretion of the implementor.

-- 4.4.2. PPP Discard Test

-- The PPP Discard Test is defined as

pppDiscardTest OBJECT IDENTIFIER ::= { pppTests 2 }

-- Invoking this test causes a PPP Discard Packet to be sent on
-- the line. ifExtnsTestResult returns success(2) if the discard
-- packet was successfully transmitted and failed(7) if an error
-- was detected on transmission. The definition of "transmission
-- error" in this context is left to the discretion of the
-- implementor.

END

5. Acknowledgements

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

6. Security Considerations

The PPP MIB affords the network operator the ability to configure and
control the PPP links of a particular system. 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.

Kastenholz [Page 23]

RFC 1471 PPP/LCP MIB June 1993

(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.

7. References

[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.

Kastenholz [Page 24]

RFC 1471 PPP/LCP MIB June 1993

[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.

[13] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple
Network Management Protocol", STD 15, RFC 1157, SNMP Research,
Performance Systems International, Performance Systems
International, MIT Laboratory for Computer Science, May 1990.

8. Author's Address

Frank Kastenholz
FTP Software, Inc.
2 High Street
North Andover, Mass 01845 USA

Phone: (508) 685-4000
EMail: [email protected]

Kastenholz [Page 25]