RFC 1230
IEEE 802.4 Token Bus MIB
RFC 1230: IEEE 802.4 Token Bus MIB 🫶
okay bestie, this one is a MIB (Management Information Base) for the IEEE 802.4 Token Bus, meaning the stuff you need to manage those networks with SNMP 🎀 It's by K. McCloghrie of Hughes LAN Systems, Inc. and R. Fox of Synoptics, Inc., dated May 1991. The header doesn't list anything it obsoletes or updates ✨
Status of This Memo 📜
This memo defines a MIB for the IEEE 802.4 Token Bus for use with the SNMP protocol. It's a product of the Transmission Working Group of the Internet Engineering Task Force (IETF). It's an IAB standards track protocol for the Internet community, and they're literally asking for discussion and suggestions for improvements 💅 For the current standardization state and status, check the current edition of the "IAB Official Protocol Standards". Distribution of this memo is unlimited. 🦋
Table of Contents 🌸
1. Abstract .............................................. 1
2. The Network Management Framework....................... 2
3. Objects ............................................... 2
3.1 Format of Definitions ................................ 3
4. Overview .............................................. 3
4.1 Scope of Definitions ................................. 3
4.2 Textual Conventions .................................. 4
4.3 Optional Objects ..................................... 4
5. Definitions ........................................... 4
6. Acknowledgements ...................................... 22
7. References ............................................ 22
8. Security Considerations................................ 23
9. Authors' Addresses..................................... 231. Abstract 🌷
This memo defines an experimental portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP-based internets. In particular, it defines managed objects for managing subnetworks that use the IEEE 802.4 Token Bus technology described in 802.4 Token-Passing Bus Access Method and Physical Layer Specifications, IEEE Standard 802.4. Main character energy 👑
2. The Network Management Framework 🧚
The Internet-standard Network Management Framework has three components, bestie:
- RFC 1155 defines the SMI, the mechanisms used for describing and naming objects for the purpose of management. RFC 1212 defines a more concise description mechanism, which is wholly consistent with the SMI.
- RFC 1156 defines MIB-I, the core set of managed objects for the Internet suite of protocols. RFC 1213, defines MIB-II, an evolution of MIB-I based on implementation experience and new operational requirements.
- RFC 1157 defines the SNMP, the protocol used for network access to managed objects.
The Framework lets new objects be defined for experimentation and evaluation ✨
3. Objects 💖
Managed objects are accessed through a virtual information store called the Management Information Base, or MIB. Objects in the MIB are defined using the subset of Abstract Syntax Notation One (ASN.1) [7] that the SMI defines. Each object has a name, a syntax, and an encoding. The name is an object identifier, an administratively assigned name that specifies an object type. The object type together with an object instance uniquely identifies one specific instantiation of the object. For human convenience, we often use a text string, called the OBJECT DESCRIPTOR, to also refer to the object type 🙈
The syntax of an object type defines the abstract data structure for that object type, and ASN.1 is used for this. However, the SMI [3] purposely restricts which ASN.1 constructs may be used. Those restrictions are explicitly made for simplicity 🍓
The encoding of an object type is simply how that object type is represented using its syntax. Implicitly tied to the syntax and encoding is how the object type is represented when it's 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 SNMP 💅
3.1. Format of Definitions 🎀
Section 5 contains contains the specification of all object types in this MIB module. The object types are defined using the conventions of the SMI, as amended by the extensions specified in [9,10].
4. Overview 🦋
This memo defines three tables, and the whole vibe is:
- the 802.4 Operational Table, containing state and operational parameter information specific to 802.4 interfaces;
- the 802.4 Initialization Table, containing the parameter information an 802.4 interface uses as the values to assign to its operational parameters upon initialization; and
- the 802.4 Statistics Table, containing 802.4 interface statistics.
A managed system has one entry in each of these tables for each of its 802.4 interfaces 🔥
This memo also defines OBJECT IDENTIFIERs. Some identify 802.4 tests, for use with the ifExtnsTestTable defined in [11], and some identify Token Bus interface Chip Sets, for use with the ifExtnsChipSet object defined in [11] 🧚
4.1. Scope of Definitions 🌈
All objects defined in this memo are registered in a single subtree within the experimental namespace [3], and they're for use with every interface that conforms to the IEEE 802.4 Token Bus Access Method [10]. Right now, this applies to interfaces where the ifType variable in the Internet-standard MIB [4,6] has the value:
iso88024-tokenBus(8)For these interfaces, the value of the ifSpecific variable in MIB-II [6] has the OBJECT IDENTIFIER value:
dot4 OBJECT IDENTIFIER ::= { experimental 7 }as defined below ✨
4.2. Textual Conventions 💜
Two new datatypes, MacAddress and OctetTime, are introduced as textual conventions in this document. These textual conventions have NO effect on the syntax or the semantics of any managed object. Objects defined using these conventions are always encoded by the rules that define their primitive type. So no changes to the SMI or SNMP are needed to accommodate them. They're adopted purely for the convenience of readers and writers chasing the elusive goal of a concise and unambiguous specification 🤓
4.3. Optional Objects 🍓
A few objects in this memo have "optional" status, so experimentation can figure out whether they're useful. If the Internet community reaches enough consensus to produce a later revision of this memo that goes into the Internet-standard MIB, these optional objects will either be removed or become mandatory 👀
5. Definitions 📖
RFC1230-MIB DEFINITIONS ::= BEGIN
-- IEEE 802.4 Token Bus MIB
IMPORTS
experimental
FROM RFC1155-SMI
OBJECT-TYPE
FROM RFC-1212;
-- This MIB Module uses the extended OBJECT-TYPE macro as
-- defined in [9].
dot4 OBJECT IDENTIFIER ::= { experimental 7 }
-- All representations of MAC addresses in this MIB Module
-- use, as a textual convention (i.e. this convention does
-- not affect their encoding), the data type:
MacAddress ::= OCTET STRING (SIZE (6)) -- a 6 octet
-- address in the
-- "canonical" order
-- defined by IEEE
-- 802.1a.
-- 16-bit addresses, if needed, are represented by setting
-- their upper 4 octets to all 0's, i.e., AAFF would be
-- represented as 00000000AAFF.
-- This specification follows the 802.4 convention of
-- specifying time intervals, which are dependent on the
-- bandwidth of the media, in units of octet time. One
-- octet time is the time taken to transmit eight bits.
-- Representation of such time intervals in this MIB Module
-- use, as a textual convention (i.e., this convention does
-- not affect their encoding), the data type:
OctetTime ::= INTEGER -- the value of a time
-- interval in units of octet
-- time.
-- The 802.4 Operational Table
-- This table contains state and parameter information which
-- is specific to 802.4 interfaces. It is mandatory that
-- systems having 802.4 interfaces implement this table in
-- addition to the generic interfaces table [4,6] and its
-- generic extensions [11].
dot4Table OBJECT-TYPE
SYNTAX SEQUENCE OF Dot4Entry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"This table contains Token Bus interface
parameters and state variables, one entry
per 802.5 interface."
::= { dot4 1 }
dot4Entry OBJECT-TYPE
SYNTAX Dot4Entry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of Token Bus status and operational
parameter values for an 802.4 interface."
INDEX { dot4IfIndex }
::= { dot4Table 1 }Okay bestie, this is where the 802.4 table gets its actual columns 💖 Here's the whole Dot4Entry row shape first, then we go column by column 🦋
Dot4Entry ::= SEQUENCE {
dot4IfIndex
INTEGER,
dot4Options
INTEGER,
dot4State
INTEGER,
dot4Commands
INTEGER,
dot4MacAddrLen
INTEGER,
dot4NextStation
MacAddress,
dot4PreviousStation
MacAddress,
dot4SlotTime
OctetTime,
dot4LastTokenRotTime
OctetTime,
dot4HiPriTokenHoldTime
OctetTime,
dot4TargetRotTimeClass4
OctetTime,
dot4TargetRotTimeClass2
OctetTime,
dot4TargetRotTimeClass0
OctetTime,
dot4TargetRotTimeRingMaint
OctetTime,
dot4RingMaintTimerInitValue
OctetTime,
dot4MaxInterSolicitCount
INTEGER (16..255),
dot4MaxRetries
INTEGER (0..7),
dot4MinPostSilencePreambLen
INTEGER,
dot4StandardRevision
INTEGER
}First up is dot4IfIndex 🔥 This one says which 802.4 interface the row is about. Its value is the same as the ifIndex object from [4,6] for that same interface, so the two tables line up perfectly 🫶
dot4IfIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of this object identifies the
802.4 interface for which this entry
contains management information. The
value of this object for a particular
interface has the same value as the
ifIndex object, defined in [4,6], for the
same interface."
::= { dot4Entry 1 }Next, dot4Options 🎀 is the "which extras are switched on" column. Each optional feature has its own number, and you add the numbers together for whatever's active. Zero means nothing extra is on, no cap 💅
dot4Options OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The optional parts of the 802.4
specification which are in use by this
station. The options of the 802.4
specification are represented by the
following values:
1 - Priority
2 - Request-With-Response
The value of this object is given by the
sum of the above representations for
those options in use on this interface.
The value zero indicates that no options
are in use."
::= { dot4Entry 2 }dot4State 🌸 tells you where the station is in its whole ring journey: other, offline, out of the ring, entering it, or fully in the ring. If the station can't tell what state it's in (say, because of an error), it reports other(1) 🙈
dot4State OBJECT-TYPE
SYNTAX INTEGER {
other(1),
offline(2),
outOfRing(3),
enteringRing(4),
inRing(5)
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The current state of the 802.4
interface. The value of other(1) is
used if the state is unknown
(e.g., due to an error condition)."
::= { dot4Entry 3 }dot4Commands 🧚 is the one you can actually write to. Setting it tells the station to change its interface state. initialize(5) loads the operational parameters from the initialization parameters, and dot4InitInRingDesired decides whether the station tries to rejoin the ring right away. There's also a little note here that the 802.4 spec suggests a station stays Offline after a remote reset until someone does a local initialize 👀 Setting it to no-op(1) does absolutely nothing, and reading it always gives you no-op(1) ✨
dot4Commands OBJECT-TYPE
SYNTAX INTEGER {
no-op(1),
enterRing(2),
exitRing(3),
reset(4),
initialize(5)
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"Setting this object causes the station
to change the state of the interface as
indicated by the specified value. An
initialize(5) command causes the
interfaceto load its operational
parameters from its initialization
parameters; the value of
dot4InitInRingDesired determines
whether the station tries to enter the
logical ring immediately.
Note that the 802.4 specification
suggests a station remain Offline after a
'remote Network Management' reset(4),
until a 'local Network Management'
initialize(5) is performed.
Setting this object to a value of
no-op(1) has no effect. When read,
this object always has the value no-op(1)."
::= { dot4Entry 4 }dot4MacAddrLen 💜 is the address-size check. It tells you whether this station reads MAC addresses as 16-bit or 48-bit, which is a vibe I respect 🫶
dot4MacAddrLen OBJECT-TYPE
SYNTAX INTEGER {
sixteenBit(1),
forty-eightBit(2)
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"This object indicates the size of MAC
addresses interpreted by this station."
::= { dot4Entry 5 }dot4NextStation 🍓 is the MAC address of whoever comes right after this station in the logical ring. It's basically the ring gossip: who's next? 👑
dot4NextStation OBJECT-TYPE
SYNTAX MacAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The MAC address of this station's
successor in the logical ring."
::= { dot4Entry 6 }dot4PreviousStation 🦋 is the mirror of that. It holds the source MAC address of the last token that was addressed to this station, so it remembers who handed it the baton last 🥹
dot4PreviousStation OBJECT-TYPE
SYNTAX MacAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The source MAC address of the last token
addressed to this station."
::= { dot4Entry 7 }dot4SlotTime ⏰ is the longest a station ever needs to wait for an immediate MAC-level response from another station. The description says this value has to be the same on every station in the 802.4 network, so nobody's out of sync 🌈
dot4SlotTime OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The maximum time any station need wait
for an immediate MAC-level response from
another station.
This value must the same in all stations on
the 802.4 network."
::= { dot4Entry 8 }dot4LastTokenRotTime 🌀 is how long the token took on its most recent lap, measured from one token arrival to the next. If it reads zero, the token isn't going around at all, which is a whole mood 💀
dot4LastTokenRotTime OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The observed token rotation time for the
last token rotation, timed from token
arrival to token arrival. A value of
zero indicates that the token is not
rotating."
::= { dot4Entry 9 }dot4HiPriTokenHoldTime 👑 is the maximum amount of time a station can hold the token to send frames of access class 6. If the priority option isn't implemented, it applies to any access class instead, so it's the one-size-fits-all rule in that case 💅
dot4HiPriTokenHoldTime OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The maximum duration for which a station
can hold the token to transmit frames of
access class 6 (if the priority option is
implemented), or of any access class (if
the priority option is not implemented)."
::= { dot4Entry 10 }Heads up, the next three columns (dot4TargetRotTimeClass4, dot4TargetRotTimeClass2 and dot4TargetRotTimeClass0) all work the same way, just for different access classes 🙈 They only mean something when the priority scheme is in use, and otherwise they're set to 0.
dot4TargetRotTimeClass4 🔥 caps how long a station can send frames at access class 4. The clock starts when the station is first allowed to start transmitting on one rotation, and it has to stop by the time the next rotation comes around ✨
dot4TargetRotTimeClass4 OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-only
STATUS mandatory
DESCRIPTION
"If the priority scheme is being used,
this value specifies a limit on how long
a station can transmit frames at access
class 4. The limit is measured from the
time the station is able to start
transmitting frames at this access class
on one rotation, to the time it must stop
transmitting frames at this access class
on the next rotation. If the priority
scheme is not being used, this object has
the value 0."
::= { dot4Entry 11 }dot4TargetRotTimeClass2 🌸 is the same deal for access class 2. Same timing window, same zero-when-no-priority rule 🎀
dot4TargetRotTimeClass2 OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-only
STATUS mandatory
DESCRIPTION
"If the priority scheme is being used,
this value specifies a limit on how long
a station can transmit frames at access
class 2. The limit is measured from the
time the station is able to start
transmitting frames at this access
class on one rotation, to the time it
must stop transmitting frames at this
access class on the next rotation. If
the priority scheme is not being used,
this object has the value 0."
::= { dot4Entry 12 }dot4TargetRotTimeClass0 🧚 finishes off the trio with access class 0, with the exact same rules as the other two 🌈
dot4TargetRotTimeClass0 OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-only
STATUS mandatory
DESCRIPTION
"If the priority scheme is being used,
this value specifies a limit on how long
a station can transmit frames at access
class 0. The limit is measured from the
time the station is able to start
transmitting frames at this access
class on one rotation, to the time it
must stop transmitting frames at this
access class on the next rotation. If
the priority scheme is not being used,
this object has the value 0."
::= { dot4Entry 13 } dot4TargetRotTimeRingMaint OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A value used to limit the duration of a
token rotation. If the duration of a
token rotation exceeds this value, the
station will not open the response window
to solicit for a new successor."
::= { dot4Entry 14 }
dot4RingMaintTimerInitValue OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value to which the
dot4TargetRotTimeRingMaint is set, each
time the station enters the ring.
A large value will cause the station to
solicit successors immediately upon entry
to the ring; a value of zero will cause
the station to defer this solicitation
for at least one token rotation."
::= { dot4Entry 15 }
dot4MaxInterSolicitCount OBJECT-TYPE
SYNTAX INTEGER (16..255)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The maximum number of consecutive token
rotations without soliciting for a
successor. If this count expires, the
station opens the response window to
solicit for a successor (providing the
duration of the current token rotation
has not exceeded
dot4TargetRotTimeRingMaint). The least
significant two bits of the count are
determined randomly by the station on a
per-use basis."
::= { dot4Entry 16 }
dot4MaxRetries OBJECT-TYPE
SYNTAX INTEGER (0..7)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The maximum number of retries of a
Request-with-Response (RWR) frame. If
the RWR option is not in use, this object
has the value 0."
::= { dot4Entry 17 }
dot4MinPostSilencePreambLen OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The minimum number of octets of preamble
on the first frame transmitted by this
station after a period of 'transmitted'
silence."
::= { dot4Entry 18 }
dot4StandardRevision OBJECT-TYPE
SYNTAX INTEGER {
rev2(2)
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The Revision number of the 802.4 standard
implemented by this station."
::= { dot4Entry 19 }Okay so this next bit is all about the knobs that control how a station behaves on the token bus ring 🫶🔥. We've got a bunch of read-only timers and counters here, and they're all tagged mandatory, so every 802.4 station has to have them, no cap 💅. The dot4TargetRotTimeRingMaint one is the bouncer for token rotations: if a rotation runs longer than this, the station just doesn't open its response window to go looking for a new successor 🙈. dot4RingMaintTimerInitValue is the starting value for that timer every time a station walks into the ring, and the vibe is that a big number makes it solicit successors right away, while zero makes it wait at least one token rotation 🦋.
dot4MaxInterSolicitCount is how many rotations in a row can go by before the station tries to solicit a successor, and it's locked between 16 and 255 ✨. The fun part is that the two lowest bits of that count get picked randomly by the station each time it's used 🎲. dot4MaxRetries covers how many times a Request-with-Response (RWR) frame gets retried, from 0 up to 7, and if RWR isn't being used at all, this one just sits at 0 🌸. dot4MinPostSilencePreambLen is the minimum amount of preamble octets on the first frame a station sends after it's been quiet for a while 🍓. And dot4StandardRevision just tells you which revision of the 802.4 standard the station follows, and here that's rev2(2) 🧚.
-- 802.4 Initialization Table
-- This table contains the parameter information used by an
-- 802.4 interface as the values to be assigned to its
-- operational parameters upon initialization. It is
-- mandatory that systems having 802.4 interfaces implement
-- this table.
dot4InitTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot4InitEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"This table contains Token Bus
initialization parameters, one entry per
802.4 interface."
::= { dot4 2 }
dot4InitEntry OBJECT-TYPE
SYNTAX Dot4InitEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of Token Bus initialization
parameters for an 802.4 interface."
INDEX { dot4InitIfIndex }
::= { dot4InitTable 1 }
Dot4InitEntry ::= SEQUENCE {
dot4InitIfIndex
INTEGER,
dot4InitSlotTime
OctetTime,
dot4InitMaxInterSolicitCount
INTEGER (16..255),
dot4InitMaxRetries
INTEGER (0..7),
dot4InitHiPriTokenHoldTime
OctetTime,
dot4InitTargetRotTimeClass4
OctetTime,
dot4InitTargetRotTimeClass2
OctetTime,
dot4InitTargetRotTimeClass0
OctetTime,
dot4InitTargetRotTimeRingMaint
OctetTime,
dot4InitRingMaintTimerInitValue
OctetTime,
dot4InitMinPostSilencePreambLen
INTEGER,
dot4InitInRingDesired
INTEGER
}
dot4InitIfIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of this object identifies the
802.4 interface for which this entry
contains management information. The
value of this object for a particular
interface has the same value as the
ifIndex object, defined in [4,6], for
the same interface."
::= { dot4InitEntry 1 }
dot4InitSlotTime OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4SlotTime when the station is
initialized."
::= { dot4InitEntry 2 }
dot4InitMaxInterSolicitCount OBJECT-TYPE
SYNTAX INTEGER (16..255)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4MaxInterSolicitCount when the station
is initialized."
::= { dot4InitEntry 3 }
dot4InitMaxRetries OBJECT-TYPE
SYNTAX INTEGER (0..7)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4MaxRetries when the station is
initialized."
::= { dot4InitEntry 4 }
dot4InitHiPriTokenHoldTime OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4HiPriTokenHoldTime when the station
is initialized."
::= { dot4InitEntry 5 }
dot4InitTargetRotTimeClass4 OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4TargetRotTimeClass4 when the station
is initialized."
::= { dot4InitEntry 6 }
dot4InitTargetRotTimeClass2 OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4TargetRotTimeClass2 when the station
is initialized."
::= { dot4InitEntry 7 }
dot4InitTargetRotTimeClass0 OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4TargetRotTimeClass0 when the station
is initialized."
::= { dot4InitEntry 8 }
dot4InitTargetRotTimeRingMaint OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4TargetRotTimeRingMaint when the station
is initialized."
::= { dot4InitEntry 9 }
dot4InitRingMaintTimerInitValue OBJECT-TYPE
SYNTAX OctetTime
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4RingMaintTimerInitValue when the
station is initialized."
::= { dot4InitEntry 10 }
dot4InitMinPostSilencePreambLen OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value assigned to the object
dot4MinPostSilencePreambLen when the
station is initialized."
::= { dot4InitEntry 11 }
dot4InitInRingDesired OBJECT-TYPE
SYNTAX INTEGER {
inRing(1),
outOfRing(2)
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"This object determines whether the
station will attempt to enter the logical
ring immediately after initialization."
::= { dot4InitEntry 12 }Now we're in the initialization table era 🎀. Think of it as the starter pack: it holds the values that get copied into the operational parameters when a station boots up 🚀. Each row is one 802.4 interface, and the table is indexed by dot4InitIfIndex, which matches the ifIndex for that same interface, referencing [4,6] ✨. Systems with 802.4 interfaces are required to implement this table, so no skipping it, bestie 💅.
Every column in the init entry is basically a "when the station starts up, set this to that" instruction 🫶. You've got slot time, inter-solicit count, retries, the hi-pri token hold time, the three target rotation times for the classes, the ring maintenance target and its init value, the minimum post-silence preamble length, and then dot4InitInRingDesired, which decides whether the station tries to join the logical ring right after it initializes 🌈. That last one is either inRing(1) or outOfRing(2), and it's read-write, so you can flip it 🦋.
-- 802.4 Statistics Table
-- This table contains Token Bus statistics, one entry per
-- 802.4 interface. It is mandatory that systems having
-- 802.4 interfaces implement this table.okay so this part is where the Token Bus stats live, and bestie, it's giving detailed 💅✨ The table is basically a big wraparound-counter party, and every field has a job.
dot4StatsTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot4StatsEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A table containing Token Bus statistics.
All the statistics are defined using the
syntax Counter as 32 bit wrap around
counters. Thus, if an interface's
hardware chip set maintains these
statistics in 16-bit counters, then the
agent must read the hardware's counters
frequently enough to prevent loss of
significance, in order to maintain
a 32-bit counter in software."
::= { dot4 3 }
dot4StatsEntry OBJECT-TYPE
SYNTAX Dot4StatsEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"An entry containing the 802.4 statistics
for a particular interface."
INDEX { dot4StatsIfIndex }
::= { dot4StatsTable 1 }
Dot4StatsEntry ::= SEQUENCE {
dot4StatsIfIndex
INTEGER,
dot4StatsTokenPasses
Counter,
dot4StatsTokenHeards
Counter,
dot4StatsNoSuccessors
Counter,
dot4StatsWhoFollows
Counter,
dot4StatsTokenPassFails
Counter,
dot4StatsNonSilences
Counter,
dot4StatsFcsErrors
Counter,
dot4StatsEbitErrors
Counter,
dot4StatsFrameFrags
Counter,
dot4StatsFrameTooLongs
Counter,
dot4StatsOverRuns
Counter,
dot4StatsDupAddresses
Counter
}Okay so the table itself is a read-only, not-accessible thing, and each entry is indexed by dot4StatsIfIndex. 🎀 Every row is one 802.4 interface, and the index is the sweet little number that picks it out.
dot4StatsIfIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of this object identifies the
802.4 interface for which this entry
contains management information. The
value of this object for a particular
interface has the same value as the
ifIndex object, defined in [4,6], for the
same interface."
::= { dot4StatsEntry 1 }
dot4StatsTokenPasses OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS optional
DESCRIPTION
"The number of times this station has
passed the token."
::= { dot4StatsEntry 2 }
dot4StatsTokenHeards OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS optional
DESCRIPTION
"The number of tokens heard by this
station."
::= { dot4StatsEntry 3 }
dot4StatsNoSuccessors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times the station could
not find a successor while believing
itself not the only station in the ring.
This can signify a faulty transmitter
condition in this station."
::= { dot4StatsEntry 4 }
dot4StatsWhoFollows OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times the station has had
to look for a new next station."
::= { dot4StatsEntry 5 }
dot4StatsTokenPassFails OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times the station failed in
passing the token to the next station."
::= { dot4StatsEntry 6 }
dot4StatsNonSilences OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of occurrences of non-silence
followed by silence in which a start
delimiter was not detected."
::= { dot4StatsEntry 7 }
dot4StatsFcsErrors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of frames received with an
incorrect FCS and the E-bit reset."
::= { dot4StatsEntry 8 }
dot4StatsEbitErrors OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of frames the station
received with the E-bit set in the
end delimiter."
::= { dot4StatsEntry 9 }
dot4StatsFrameFrags OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of occurrences of receiving a
start delimiter followed by another start
delimiter, an invalid symbol sequence or
silence, without an intervening end
delimiter."
::= { dot4StatsEntry 10 }
dot4StatsFrameTooLongs OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of frames that were received
that were larger than the media's MTU."
::= { dot4StatsEntry 11 }
dot4StatsOverRuns OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times a FIFO overrun was
detected in the station."
::= { dot4StatsEntry 12 }
dot4StatsDupAddresses OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times this station
detected another station using the same
MAC address."
::= { dot4StatsEntry 13 }Next up is the 802.4 interface tests branch, and it's giving very "don't poke this unless you mean it" energy 🙈 The tests hang off dot4Tests, and there's a whole comment explaining how they plug into the interfaces table extensions from [11].
-- 802.4 Interface Tests
dot4Tests OBJECT IDENTIFIER ::= { dot4 5 }
-- The extensions to the interfaces table proposed in [11]
-- define a table object, ifExtnsTestTable, through which a
-- network manager can instruct an agent to test an interface
-- for various faults. A test to be performed is identified
-- (as the value of ifExtnsTestType) via an OBJECT IDENTIFIER.
-- When a test fails, the object ifExtnsTestCode, defined in
-- [11], may contain a media-specific error-code. For 802.4
-- interfaces, the following is defined as the value of
-- ifExtnsTestCode when a test fails because the modem could
-- not be initialized:
dot4Errors OBJECT IDENTIFIER ::= { dot4 4 }
dot4ModemInitFailed OBJECT IDENTIFIER ::= { dot4Errors 1 }
-- The Full-Duplex Loop Back Test is a common test, defined
-- in [11] as:
--
-- testFullDuplexLoopBack
--
-- Invoking this test on a 802.4 interface causes the
-- interface to check the path from memory through the chip
-- set's serial interface back to memory, thus checking the
-- proper functioning of the transmit and receive machines
-- of the token bus hardware.
-- This test may only be invoked when the interface is
-- the Offline state.
-- The FIFO Path test is defined by:
testFifoPath OBJECT IDENTIFIER ::= { dot4Tests 1 }
-- Invoking this test causes the interface to check the path
-- from memory to the chip set's FIFO and back to memory.
-- This test checks the hosts interface to the token bus
-- hardware. This test may only be invoked when the
-- interface is the Offline state.
-- The External Loopback test is defined by:
testExternalLoopback OBJECT IDENTIFIER ::= { dot4Tests 2 }
-- Invoking this test causes the interface to check the path
-- from memory through the chip set and out onto the network
-- for external (e.g., at the head-end) loopback through the
-- chip set to memory. This test checks the host's interface
-- to the 802.4 network. This test is liable to cause
-- serious disruption if invoked on an operational network.Heads up, the External Loopback test is flagged as liable to cause serious disruption on a live network, so please don't go poking it on prod 😭🚨
-- 802.4 Hardware Chip Sets
dot4ChipSets OBJECT IDENTIFIER ::= { dot4 6 }
-- The extensions to the interfaces table proposed in [11]
-- define an object, ifExtnsChipSet, with the syntax of
-- OBJECT IDENTIFIER, to identify the hardware chip set in
-- use by an interface. That definition specifies just
-- one applicable object identifier:
--
-- unknownChipSet
--
-- for use as the value of ifExtnsChipSet when the specific
-- chip set is unknown.
--
-- This MIB defines the following for use as values of
-- ifExtnsChipSet:
-- for use as values of ifExtnsChipSet
-- Motorola 68824 Token Bus Controller
chipSetMc68824 OBJECT IDENTIFIER ::= { dot4ChipSets 1 }
ENDAnd that's the whole MIB, periodt ✨🦋 The chip set section is short but it's the one that lets an interface say which Motorola 68824 it's running, so iconic.
6. Acknowledgements ✨
okay so this one's a shoutout section 🫶 this doc was cooked up under the IETF's Transmission Working Group, and the people who gave comments get credited here. bestie, the squad:
- Brian Kline, Hughes LAN Systems, Inc. 💜
- Bruce Lieberman, Hughes LAN Systems, Inc. 🌸
- Marshall T. Rose, Performance Systems International, Inc. 👑
7. References 📚
okay the receipts! this is every doc the RFC leans on, and I'm keeping every detail because implementers need the exact sources 💅
[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", 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 (SNMP), RFC 1157, SNMP Research, Performance Systems International, Performance Systems International, MIT Laboratory for Computer Science, May 1990.
[6] McCloghrie K., and M. Rose, Editors, "Management Information Base for Network Management of TCP/IP-based internets", 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] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions", RFC 1212, Performance Systems International, Hughes LAN Systems, March 1991.
[10] Token-Passing Bus Access Method and Physical Layer Specifications, Institute of Electrical and Electronic Engineers, IEEE Standard 802.4, May 1988.
[11] McCloghrie, K., Editor, "Extensions to the Generic-Interface MIB", RFC 1229, Hughes LAN Systems, May 1991.
8. Security Considerations 🔒
okay, the security section is kinda short and I'm not gonna pretend otherwise. the memo says it: "Security issues are not discussed in this memo." 💀 so no security analysis here, bestie. that's the whole tea 🫠
9. Authors' Addresses 🖊️
the people who wrote it and how to reach them 🦋
Keith McCloghrie Hughes LAN Systems, Inc. 1225 Charleston Road Mountain View, CA 94043
Phone: (415) 966-7934 EMail: kzm@hls.com
Richard Fox Synoptics, Inc. 4401 Great America Pkwy PO Box 58185 Santa Clara, Cal. 95052
Phone: (408) 764-1372 EMail: rfox@synoptics.com
📦 where this page comes from
- ietf: rfc1230 1991-05
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms