Rfc | 1398 |
Title | Definitions of Managed Objects for the Ethernet-Like Interface
Types |
Author | F. Kastenholz |
Date | January 1993 |
Format: | TXT, HTML |
Obsoletes | RFC1284 |
Obsoleted by | RFC1623 |
Status: | DRAFT STANDARD |
|
Network Working Group F. Kastenholz
Request for Comments: 1398 FTP Software, Inc.
Obsoletes: 1284 January 1993
Definitions of Managed Objects for
the Ethernet-like Interface Types
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 defines objects for managing ethernet-like objects.
Table of Contents
1. The Network Management Framework ...................... 1
2. Objects ............................................... 2
2.1 Format of Definitions ................................ 2
3. Overview .............................................. 3
4. Definitions ........................................... 4
4.1 The Ethernet-like Statistics Group ................... 4
4.2 The Ethernet-like Collision Statistics Group ......... 11
4.3 802.3 Tests .......................................... 12
4.4 802.3 Hardware Chipsets .............................. 14
5. Change Log ............................................ 14
6. Acknowledgements ...................................... 16
7. References ............................................ 16
8. Security Considerations ............................... 17
9. Author's Address ...................................... 17
1. The Network Management Framework
The Internet-standard Network Management Framework consists of three
components. They are:
STD 16/RFC 1155 [3] which defines the SMI, the mechanisms used for
describing and naming objects for the purpose of management. STD
16/RFC 1212 [13] defines a more concise description mechanism,
which is wholly consistent with the SMI.
RFC 1156 [4] which defines MIB-I, the core set of managed objects
for the Internet suite of protocols. STD 17/RFC 1213 [6] defines
MIB-II, an evolution of MIB-I based on implementation experience
and new operational requirements.
STD 15/RFC 1157 [5] 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) [7]
defined in the SMI. In particular, each object has a name, a syntax,
and an encoding. The name is an object identifier, an
administratively assigned name, which specifies an object type. 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 OBJECT
DESCRIPTOR, to also refer to the object type.
The syntax of an object type defines the abstract data structure
corresponding to that object type. The ASN.1 language is used for
this purpose. However, the SMI [3] purposely restricts the ASN.1
constructs which may be used. These restrictions are explicitly made
for simplicity.
The encoding of an object type is simply how that object type is
represented using the object type's syntax. Implicitly tied to the
notion of an object type's syntax and encoding is how the object type
is represented when being transmitted on the network.
The SMI specifies the use of the basic encoding rules of ASN.1 [8],
subject to the additional requirements imposed by the SNMP.
2.1. Format of Definitions
Section 4 contains 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 [13].
3. Overview
Instances of these object types represent attributes of an interface
to an ethernet-like communications medium. At present, ethernet-like
media are identified by three values of the ifType object in the
Internet-standard MIB:
ethernet-csmacd(6)
iso88023-csmacd(7)
starLan(11)
For these interfaces, the value of the ifSpecific variable in the
MIB-II [6] has the OBJECT IDENTIFIER value:
dot3 OBJECT IDENTIFER ::= { transmission 7 }
The definitions presented here are based on the IEEE 802.3 Layer
Management Specification [9], as originally interpreted by Frank
Kastenholz of Interlan in [10]. Implementors of these MIB objects
should note that the IEEE document explicitly describes (in the form
of Pascal pseudocode) when, where, and how various MAC attributes are
measured. The IEEE document also describes the effects of MAC
actions that may be invoked by manipulating instances of the MIB
objects defined here.
To the extent that some of the attributes defined in [9] are
represented by previously defined objects in the Internet- standard
MIB or in the Generic Interface Extensions MIB [11], such attributes
are not redundantly represented by objects defined in this memo.
Among the attributes represented by objects defined in other memos
are the number of octets transmitted or received on a particular
interface, the number of frames transmitted or received on a
particular interface, the promiscuous status of an interface, the MAC
address of an interface, and multicast information associated with an
interface.
The relationship between an ethernet-like interface and an interface
in the context of the Internet-standard MIB is one-to-one. As such,
the value of an ifIndex object instance can be directly used to
identify corresponding instances of the objects defined herein.
4. Definitions
RFC1398-MIB DEFINITIONS ::= BEGIN
IMPORTS
Counter, Gauge
FROM RFC1155-SMI
transmission
FROM RFC1213-MIB
OBJECT-TYPE
FROM RFC-1212;
-- This MIB module uses the extended OBJECT-TYPE macro as
-- defined in RFC-1212.
-- this is the MIB module for ethernet-like objects
dot3 OBJECT IDENTIFIER ::= { transmission 7 }
-- { dot3 1 } is obsolete and has been deleted.
4.1. The Ethernet-like Statistics Group
-- the Ethernet-like Statistics group
-- Implementation of this group is mandatory
dot3StatsTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot3StatsEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Statistics for a collection of ethernet-like
interfaces attached to a particular system."
::= { dot3 2 }
dot3StatsEntry OBJECT-TYPE
SYNTAX Dot3StatsEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Statistics for a particular interface to an
ethernet-like medium."
INDEX { dot3StatsIndex }
::= { dot3StatsTable 1 }
Dot3StatsEntry ::= SEQUENCE {
dot3StatsIndex
INTEGER,
dot3StatsAlignmentErrors
Counter,
dot3StatsFCSErrors
Counter,
dot3StatsSingleCollisionFrames
Counter,
dot3StatsMultipleCollisionFrames
Counter,
dot3StatsSQETestErrors
Counter,
dot3StatsDeferredTransmissions
Counter,
dot3StatsLateCollisions
Counter,
dot3StatsExcessiveCollisions
Counter,
dot3StatsInternalMacTransmitErrors
Counter,
dot3StatsCarrierSenseErrors
Counter,
dot3StatsFrameTooLongs
Counter,
dot3StatsInternalMacReceiveErrors
Counter
}
dot3StatsIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"An index value that uniquely identifies an
interface to an ethernet-like medium. The
interface identified by a particular value of
this index is the same interface as identified
by the same value of ifIndex."
::= { dot3StatsEntry 1 }
dot3StatsAlignmentErrors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of frames received on a particular
interface that are not an integral number of
octets in length and do not pass the FCS check.
The count represented by an instance of this
object is incremented when the alignmentError
status is returned by the MAC service to the
LLC (or other MAC user). Received frames for
which multiple error conditions obtain are,
according to the conventions of IEEE 802.3
Layer Management, counted exclusively according
to the error status presented to the LLC."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 2 }
dot3StatsFCSErrors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of frames received on a particular
interface that are an integral number of octets
in length but do not pass the FCS check.
The count represented by an instance of this
object is incremented when the frameCheckError
status is returned by the MAC service to the
LLC (or other MAC user). Received frames for
which multiple error conditions obtain are,
according to the conventions of IEEE 802.3
Layer Management, counted exclusively according
to the error status presented to the LLC."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 3 }
dot3StatsSingleCollisionFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of successfully transmitted frames on
a particular interface for which transmission
is inhibited by exactly one collision.
A frame that is counted by an instance of this
object is also counted by the corresponding
instance of either the ifOutUcastPkts or
ifOutNUcastPkts object and is not counted by
the corresponding instance of the
dot3StatsMultipleCollisionFrames object."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 4 }
dot3StatsMultipleCollisionFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of successfully transmitted frames on
a particular interface for which transmission
is inhibited by more than one collision.
A frame that is counted by an instance of this
object is also counted by the corresponding
instance of either the ifOutUcastPkts or
ifOutNUcastPkts object and is not counted by
the corresponding instance of the
dot3StatsSingleCollisionFrames object."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 5 }
dot3StatsSQETestErrors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of times that the SQE TEST ERROR
message is generated by the PLS sublayer for a
particular interface. The SQE TEST ERROR
message is defined in section 7.2.2.2.4 of
ANSI/IEEE 802.3-1985 and its generation is
described in section 7.2.4.6 of the same
document."
REFERENCE
"ANSI/IEEE Std 802.3-1985 Carrier Sense
Multiple Access with Collision Detection Access
Method and Physical Layer Specifications"
::= { dot3StatsEntry 6 }
dot3StatsDeferredTransmissions OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of frames for which the first
transmission attempt on a particular interface
is delayed because the medium is busy.
The count represented by an instance of this
object does not include frames involved in
collisions."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 7 }
dot3StatsLateCollisions OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times that a collision is
detected on a particular interface later than
512 bit-times into the transmission of a
packet.
Five hundred and twelve bit-times corresponds
to 51.2 microseconds on a 10 Mbit/s system. A
(late) collision included in a count
represented by an instance of this object is
also considered as a (generic) collision for
purposes of other collision-related
statistics."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 8 }
dot3StatsExcessiveCollisions OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of frames for which transmission on a
particular interface fails due to excessive
collisions."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 9 }
dot3StatsInternalMacTransmitErrors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of frames for which transmission on a
particular interface fails due to an internal
MAC sublayer transmit error. A frame is only
counted by an instance of this object if it is
not counted by the corresponding instance of
either the dot3StatsLateCollisions object, the
dot3StatsExcessiveCollisions object, or the
dot3StatsCarrierSenseErrors object.
The precise meaning of the count represented by
an instance of this object is implementation-
specific. In particular, an instance of this
object may represent a count of transmission
errors on a particular interface that are not
otherwise counted."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 10 }
dot3StatsCarrierSenseErrors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times that the carrier sense
condition was lost or never asserted when
attempting to transmit a frame on a particular
interface.
The count represented by an instance of this
object is incremented at most once per
transmission attempt, even if the carrier sense
condition fluctuates during a transmission
attempt."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 11 }
-- { dot3StatsEntry 12 } is not assigned
dot3StatsFrameTooLongs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of frames received on a particular
interface that exceed the maximum permitted
frame size.
The count represented by an instance of this
object is incremented when the frameTooLong
status is returned by the MAC service to the
LLC (or other MAC user). Received frames for
which multiple error conditions obtain are,
according to the conventions of IEEE 802.3
Layer Management, counted exclusively according
to the error status presented to the LLC."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 13 }
-- { dot3StatsEntry 14 } is not assigned
-- { dot3StatsEntry 15 } is not assigned
dot3StatsInternalMacReceiveErrors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of frames for which reception on a
particular interface fails due to an internal
MAC sublayer receive error. A frame is only
counted by an instance of this object if it is
not counted by the corresponding instance of
either the dot3StatsFrameTooLongs object, the
dot3StatsAlignmentErrors object, or the
dot3StatsFCSErrors object.
The precise meaning of the count represented by
an instance of this object is implementation-
specific. In particular, an instance of this
object may represent a count of receive errors
on a particular interface that are not
otherwise counted."
REFERENCE
"IEEE 802.3 Layer Management"
::= { dot3StatsEntry 16 }
4.2. The Ethernet-like Collision Statistics Group
-- the Ethernet-like Collision Statistics group
-- Implementation of this group is optional; it is appropriate
-- for all systems which have the necessary metering
dot3CollTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot3CollEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A collection of collision histograms for a
particular set of interfaces."
::= { dot3 5 }
dot3CollEntry OBJECT-TYPE
SYNTAX Dot3CollEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A cell in the histogram of per-frame
collisions for a particular interface. An
instance of this object represents the
frequency of individual MAC frames for which
the transmission (successful or otherwise) on a
particular interface is accompanied by a
particular number of media collisions."
INDEX { dot3CollIndex, dot3CollCount }
::= { dot3CollTable 1 }
Dot3CollEntry ::= SEQUENCE {
dot3CollIndex
INTEGER,
dot3CollCount
INTEGER,
dot3CollFrequencies
Counter
}
dot3CollIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The index value that uniquely identifies the
interface to which a particular collision
histogram cell pertains. The interface
identified by a particular value of this index
is the same interface as identified by the same
value of ifIndex."
::= { dot3CollEntry 1 }
dot3CollCount OBJECT-TYPE
SYNTAX INTEGER (1..16)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of per-frame media collisions for
which a particular collision histogram cell
represents the frequency on a particular
interface."
::= { dot3CollEntry 2 }
dot3CollFrequencies OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A count of individual MAC frames for which the
transmission (successful or otherwise) on a
particular interface is accompanied by a
particular number of media collisions."
::= { dot3CollEntry 3 }
4.3. 802.3 Tests
-- 802.3 Tests
-- The ifExtnsTestTable defined in RFC 1229 provides a common
-- means for a manager to test any interface corresponding to
-- a value of ifIndex.
-- At this time, one well known test (testFullDuplexLoopBack) is
-- defined in RFC 1229. For ethernet-like interfaces, this test
-- configures the MAC chip and executes an internal loopback
-- test of memory and the MAC chip logic. This loopback test can
-- only be executed if the interface is offline. Once the test
-- has completed, the MAC chip should be reinitialized for network
-- operation, but it should remain offline.
-- If an error occurs during a test, the object ifExtnsTestResult
-- (defined in RFC 1229) will be set to failed(7). The following
-- two OBJECT IDENTIFIERs may be used to provided more
-- information as values for the object ifExtnsTestCode in
-- RFC 1229:
dot3Errors OBJECT IDENTIFIER ::= { dot3 7 }
-- couldn't initialize MAC chip for test
dot3ErrorInitError OBJECT IDENTIFIER ::= { dot3Errors 1 }
-- expected data not received (or not
-- received correctly) in loopback test
dot3ErrorLoopbackError OBJECT IDENTIFIER ::= { dot3Errors 2 }
-- Tests
-- TDR Test
-- Another test, specific to ethernet-like interfaces with the
-- exception of 10BaseT and 10BaseF, is Time-domain Reflectometry
(TDR).
-- The TDR value may be useful in determining the approximate
distance
-- to a cable fault. It is advisable to repeat this test to
check for
-- a consistent resulting TDR value, to verify that there is a
fault.
dot3Tests OBJECT IDENTIFIER ::= { dot3 6 }
dot3TestTdr OBJECT IDENTIFIER ::= { dot3Tests 1 }
-- A TDR test returns as its result the time interval, measured
-- in 10 MHz ticks or 100 nsec units, between the start of
-- TDR test transmission and the subsequent detection of a
-- collision or deassertion of carrier. On successful completion
-- of a TDR test, the appropriate instance of ifExtnsTestResult
-- contains the OBJECT IDENTIFIER of the MIB object which
-- contains the value of this time interval.
4.4. 802.3 Hardware Chipsets
-- 802.3 Hardware Chipsets
-- The object ifExtnsChipSet is provided in RFC 1229 to identify
-- the MAC hardware used to communcate on an interface. The
-- following hardware chipsets are provided for 802.3:
dot3ChipSets OBJECT IDENTIFIER ::= { dot3 8 }
dot3ChipSetAMD OBJECT IDENTIFIER ::= { dot3ChipSets 1 }
dot3ChipSetAMD7990 OBJECT IDENTIFIER ::= { dot3ChipSetAMD 1 }
dot3ChipSetAMD79900 OBJECT IDENTIFIER ::= { dot3ChipSetAMD 2 }
dot3ChipSetIntel OBJECT IDENTIFIER ::= { dot3ChipSets 2 }
dot3ChipSetIntel82586 OBJECT IDENTIFIER ::= { dot3ChipSetIntel 1 }
dot3ChipSetIntel82596 OBJECT IDENTIFIER ::= { dot3ChipSetIntel 2 }
dot3ChipSetSeeq OBJECT IDENTIFIER ::= { dot3ChipSets 3 }
dot3ChipSetSeeq8003 OBJECT IDENTIFIER ::= { dot3ChipSetSeeq 1 }
dot3ChipSetNational OBJECT IDENTIFIER ::= { dot3ChipSets 4 }
dot3ChipSetNational8390 OBJECT IDENTIFIER ::=
{ dot3ChipSetNational 1 }
dot3ChipSetNationalSonic OBJECT IDENTIFIER ::=
{ dot3ChipSetNational 2 }
dot3ChipSetFujitsu OBJECT IDENTIFIER ::= { dot3ChipSets 5 }
dot3ChipSetFujitsu86950 OBJECT IDENTIFIER ::=
{ dot3ChipSetFujitsu 1 }
dot3ChipSetFujitsu86960 OBJECT IDENTIFIER ::=
{ dot3ChipSetFujitsu 2 }
-- For those chipsets not represented above, OBJECT IDENTIFIER
-- assignment is required in other documentation, e.g., assignment
-- within that part of the registration tree delegated to
-- individual enterprises (see RFC 1155).
END
5. Change Log
(1) Replace old "Historical Perspective" boilerplate with the
new "The Network Management Framework" boilerplate.
(2) Remove the "slime text".
(3) Updated the reference to the Interface Extensions mib to
reflect its new RFC status.
(4) Change the status of the memo section to hold the new
suggested text.
(5) References in ASN.1 comments were changed from the [#]
form to name the actual document being referred to. These
references are now meaningful when the ASN.1 is read
outside of the RFC.
(6) The IMPORTS section of the ASN.1 has been updated to
reflect that the OBJECT-TYPE macro is imported from RFC-
1212.
(7) The the Generic Ethernet-like group, containing
dot3Index, dot3InitializeMac, dot3MacSubLayerStatus,
dot3MulticastReceiveStatus, dot3TxEnabled, and
dot3TestTdrValue has been deprecated as a result of the
implementation experience presented at the San Diego IETF
meeting.
(8) dot3StatsInRangeLengthErrors and
dot3StatsOutOfRangeLengthFields have been deprecated as a
result of the implementation experience presented at the
San Diego IETF meeting.
(9) Update the acknowledgements section to reflect this
document's history, etc.
(10) REFERENCE clauses have been added to all of the MIB
objects which are being retained.
12 August 1992
(1) Removed all deprecated objects.
(2) Rephrased the description of the TDR test OID to reflect
the fact that dot3TestTdrValue is no more.
ifExtnsTestResult still points to the object containing
the result, the text simply does not refer to
dot3TestTdrValue. I could have deleted the Test, but the
OID should then remain reserved. I figured that it would
be just as easy to rephrase the definition of the test.
13 august 1992
(1) Add fuji. 86960
6. Acknowledgements
This document was produced by the Ethernet MIB Working Group.
This document is based on the Proposed Standard Ethernet MIB, RFC
1284 [14], of which John Cook of Chipcom was the editor. The
Ethernet MIB Working Group gathered implementation experience of the
variables specified in RFC 1284 and used that information to develop
this revised MIB.
RFC 1284, in turn, is based on a document written by Frank Kastenholz
of Interlan entitled IEEE 802.3 Layer Management Draft M compatible
MIB for TCP/IP Networks [10]. This document has been modestly
reworked, initially by the SNMP Working Group, and then by the
Transmission Working Group, to reflect the current conventions for
defining objects for MIB interfaces. James Davin, of the MIT
Laboratory for Computer Science, and Keith McCloghrie of Hughes LAN
Systems, contributed to later drafts of this memo. Marshall Rose of
Performance Systems International, Inc. converted the document into
its current concise format. Anil Rijsinghani of DEC contributed text
that more adequately describes the TDR test. Thanks to Frank
Kastenholz of Interlan and Louis Steinberg of IBM for their
experimentation.
7. References
[1] Cerf, V., "IAB Recommendations for the Development of Internet
Network Management Standards", RFC 1052, NRI, April 1988.
[2] Cerf, V., "Report of the Second Ad Hoc Network Management Review
Group", RFC 1109, NRI, August 1989.
[3] 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.
[4] McCloghrie K., and M. Rose, "Management Information Base for
Network Management of TCP/IP-based internets", RFC 1156, Hughes
LAN Systems, Performance Systems International, May 1990.
[5] 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.
[6] Rose M., Editor, "Management Information Base for Network
Management of TCP/IP-based internets: MIB-II", STD 17, RFC 1213,
Performance Systems International, March 1991.
[7] Information processing systems - Open Systems Interconnection -
Specification of Abstract Syntax Notation One (ASN.1),
International Organization for Standardization, International
Standard 8824, December 1987.
[8] 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.
[9] IEEE, "IEEE 802.3 Layer Management", November 1988.
[10] Kastenholz, F., "IEEE 802.3 Layer Management Draft compatible MIB
for TCP/IP Networks", electronic mail message to mib-
wg@nnsc.nsf.net, 9 June 1989.
[11] McCloghrie, K., Editor, Extensions to the Generic-Interface MIB,
RFC 1229, Hughes LAN Systems, Inc., May 1991.
[12] IEEE, "Carrier Sense Multiple Access with Collision Detection
(CSMA/CD) Access Method and Physical Layer Specifications",
ANSI/IEEE Std 802.3-1985.
[13] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions",
STD 16, RFC 1212, Performance Systems International, Hughes LAN
Systems, March 1991.
[14] Cook, J., Editor, "Definitions of Managed Objects for Ethernet-
Like Interface Types", RFC 1284, Chipcom Corporation, December
1991.
8. Security Considerations
Security issues are not discussed in this memo.
9. Author's Address
Frank Kastenholz
2 High Street
North Andover, MA 01845-2620
Phone: (508) 685-4000
EMail: kasten@ftp.com