RFC 3291
Textual Conventions for Internet Network Addresses
Textual Conventions for Internet Network Addresses 🦋
Bestie, this is RFC 3291, published in May 2002 🌸 on the Standards Track. It was written by M. Daniele (Consultant), B. Haberman (Consultant), S. Routhier (Wind River Systems, Inc.), and J. Schoenwaelder (TU Braunschweig), all for the Network Working Group ✨. It obsoletes RFC 2851, so that older doc is now replaced by this one 👑.
Status of this Memo
This document is an Internet standards track protocol for the whole Internet community, and it's literally asking for discussion and suggestions 🫶. For the current standardization state and status, check the "Internet Official Protocol Standards" (STD 1). Distribution of this memo is unlimited 💅.
Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved. 💜
Abstract
Okay so this MIB module defines textual conventions (TCs) to represent commonly used Internet network layer addressing information 🧚. The whole point is that these TCs get imported and used in MIB modules that would otherwise make up their own representations ✨.
This document obsoletes RFC 2851.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. The SNMP Management Framework . . . . . . . . . . . . . . . . 4
3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Usage Hints . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1 Table Indexing . . . . . . . . . . . . . . . . . . . . . . . . 12
4.2 Uniqueness of Addresses . . . . . . . . . . . . . . . . . . . 12
4.3 Multiple Addresses per Host . . . . . . . . . . . . . . . . . 13
4.4 Resolving DNS Names . . . . . . . . . . . . . . . . . . . . . 13
5. Table Indexing Example . . . . . . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 16
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
8. Intellectual Property Notice . . . . . . . . . . . . . . . . . 16
9. Changes from RFC 2851 . . . . . . . . . . . . . . . . . . . . 16
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 201. Introduction ✨
Several standards-track MIB modules use the IpAddress SMIv2 base type 🌷. That limits where these MIB modules can be used to IP Version 4 (IPv4), since the IpAddress SMIv2 base type can only hold 4 byte IPv4 addresses 🙈. It has become a real problem with the arrival of IP Version 6 (IPv6) addresses [19] 😭.
This document defines multiple textual conventions as a mechanism to express generic Internet network layer addresses inside MIB module specifications 🎀. The solution is compatible with SMIv2 (STD 58) and SMIv1 (STD 16). New MIB definitions that need to express network layer Internet addresses SHOULD use the textual conventions defined in this memo 💖. New MIB modules SHOULD NOT use the SMIv2 IpAddress base type anymore 🚫.
A generic Internet address is made of two objects: one whose syntax is InetAddressType, and another whose syntax is InetAddress 🦋. The value of the first object decides how the value of the second object gets encoded. The InetAddress textual convention represents an opaque Internet address value, and the InetAddressType enumeration is used to "cast" that InetAddress value into a concrete textual convention for the address type 💅. Using multiple textual conventions like this lets each address type show its own display characteristics, and it keeps the set of defined Internet address types extensible 🌈.
The textual conventions in this document can also represent generic Internet subnets and Internet address ranges 🍓. A generic Internet subnet is represented by three objects: one with the syntax InetAddressType, a second with the syntax InetAddress, and a third with the syntax InetAddressPrefixLength. The InetAddressType value again decides the concrete format of the InetAddress value, while the InetAddressPrefixLength identifies the Internet network address prefix 🧠.
A generic range of consecutive Internet addresses is represented by three objects 💜. The first one has the syntax InetAddressType, while the remaining two have the syntax InetAddress and specify the start and end of the address range. The InetAddressType value again decides the format of the InetAddress values ✨.
The textual conventions in this document can be used to define Internet addresses with DNS domain names as well as IPv4 and IPv6 addresses 🌸. A MIB designer can write compliance statements to say that only a subset of the possible address types must be supported by a compliant implementation 🫧.
MIB developers who need to represent Internet addresses SHOULD use these definitions whenever they apply, rather than defining their own constructs 👑. Even MIB modules that only need to represent IPv4 or IPv6 addresses SHOULD use the InetAddressType/InetAddress textual conventions defined in this memo 🔥.
There are lots of widely deployed MIB modules that use IPv4 addresses and need to be revised to support IPv6 🥺. These MIBs can be sorted into the following categories:
- MIB modules which define management information that is, in principle, IP version neutral, but the MIB currently uses addressing constructs specific to a certain IP version.
- MIB modules which define management information that is specific to a particular IP version (either IPv4 or IPv6) and which is very unlikely to ever be applicable to another IP version.
MIB modules of the first type SHOULD provide object definitions (e.g., tables) that work with all versions of IP 💖. In particular, when revising a MIB module which contains IPv4 specific tables, it is suggested to define new tables using the textual conventions defined in this memo, which support all versions of IP 🦋. The status of the new tables SHOULD be "current", while the status of the old IP version specific tables SHOULD be changed to "deprecated" 🫶. The other approach, having multiple similar tables for different IP versions, is strongly discouraged 🙅♀️.
MIB modules of the second type, which are inherently IP version specific, do not need to be redefined 🌷. Note that even in this case, any additions to these MIB modules or new IP version specific MIB modules SHOULD use the textual conventions defined in this memo 💅.
MIB developers SHOULD NOT use the textual conventions defined in this document to represent generic transport layer addresses 🚫. Instead, the SMIv2 TAddress textual convention and associated definitions should be used for transport layer addresses 🌈.
The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT" and "MAY" in this document are to be interpreted as described in RFC 2119 [1] 🎀.
2. The SNMP Management Framework 🧚
The SNMP Management Framework currently has five major components 🍓:
- An overall architecture, described in RFC 2571 [2].
- Mechanisms for describing and naming objects and events for the purpose of management. The first version of this Structure of Management Information (SMI) is called SMIv1 and is described in STD 16, RFC 1155 [3], STD 16, RFC 1212 [4] and RFC 1215 [5]. The second version, called SMIv2, is described in STD 58, RFC 2578 [6], STD 58, RFC 2579 [7] and STD 58, RFC 2580 [8].
- Message protocols for transferring management information. The first version of the SNMP message protocol is called SNMPv1 and is described in STD 15, RFC 1157 [9]. A second version of the SNMP message protocol, which is not an Internet standards track protocol, is called SNMPv2c and is described in RFC 1901 [10] and RFC 1906 [11]. The third version of the message protocol is called SNMPv3 and is described in RFC 1906 [11], RFC 2572 [12] and RFC 2574 [13].
- Protocol operations for accessing management information. The first set of protocol operations and associated PDU formats is described in STD 15, RFC 1157 [9]. A second set of protocol operations and associated PDU formats is described in RFC 1905 [14].
- A set of fundamental applications described in RFC 2573 [15] and the view-based access control mechanism described in RFC 2575 [16].
A more detailed introduction to the current SNMP Management Framework can be found in RFC 2570 [17] 📚.
Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB 🗂️. Objects in the MIB are defined using the mechanisms defined in the SMI ✨.
This memo specifies a MIB module that is compliant to the SMIv2 💜. A MIB conforming to the SMIv1 can be produced through the appropriate translations. The resulting translated MIB must be semantically equivalent, except where objects or events are omitted because no translation is possible (use of Counter64) 🙈. Some machine readable information in SMIv2 will be converted into textual descriptions in SMIv1 during the translation process 🌸. However, this loss of machine readable information is not considered to change the semantics of the MIB 🫧.
3. Definitions 💖
Here's the whole MIB module, copied exactly as written:
INET-ADDRESS-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, mib-2, Unsigned32 FROM SNMPv2-SMI
TEXTUAL-CONVENTION FROM SNMPv2-TC;
inetAddressMIB MODULE-IDENTITY
LAST-UPDATED "200205090000Z"
ORGANIZATION
"IETF Operations and Management Area"
CONTACT-INFO
"Juergen Schoenwaelder (Editor)
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig, Germany
Phone: +49 531 391-3289
EMail: schoenw@ibr.cs.tu-bs.de
Send comments to <mibs@ops.ietf.org>."
DESCRIPTION
"This MIB module defines textual conventions for
representing Internet addresses. An Internet
address can be an IPv4 address, an IPv6 address
or a DNS domain name. This module also defines
textual conventions for Internet port numbers,
autonomous system numbers and the length of an
Internet address prefix."
REVISION "200205090000Z"
DESCRIPTION
"Second version, published as RFC 3291. This
revisions contains several clarifications and it
introduces several new textual conventions:
InetAddressPrefixLength, InetPortNumber,
InetAutonomousSystemNumber, InetAddressIPv4z,
and InetAddressIPv6z."
REVISION "200006080000Z"
DESCRIPTION
"Initial version, published as RFC 2851."
::= { mib-2 76 }okay so now we get to the textual conventions, and bestie, these are the building blocks for every address in the whole MIB ✨
InetAddressType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"A value that represents a type of Internet address.
unknown(0) An unknown address type. This value MUST
be used if the value of the corresponding
InetAddress object is a zero-length string.
It may also be used to indicate an IP address
which is not in one of the formats defined
below.
ipv4(1) An IPv4 address as defined by the
InetAddressIPv4 textual convention.
ipv6(2) A global IPv6 address as defined by the
InetAddressIPv6 textual convention.
ipv4z(3) A non-global IPv4 address including a zone
index as defined by the InetAddressIPv4z
textual convention.
ipv6z(4) A non-global IPv6 address including a zone
index as defined by the InetAddressIPv6z
textual convention.
dns(16) A DNS domain name as defined by the
InetAddressDNS textual convention.
Each definition of a concrete InetAddressType value must be
accompanied by a definition of a textual convention for use
with that InetAddressType.
To support future extensions, the InetAddressType textual
convention SHOULD NOT be sub-typed in object type definitions.
It MAY be sub-typed in compliance statements in order to
require only a subset of these address types for a compliant
implementation.
Implementations must ensure that InetAddressType objects
and any dependent objects (e.g. InetAddress objects) are
consistent. An inconsistentValue error must be generated
if an attempt to change an InetAddressType object would,
for example, lead to an undefined InetAddress value. In
particular, InetAddressType/InetAddress pairs must be
changed together if the address type changes (e.g. from
ipv6(2) to ipv4(1))."
SYNTAX INTEGER {
unknown(0),
ipv4(1),
ipv6(2),
ipv4z(3),
ipv6z(4),
dns(16)
}So InetAddressType is basically the "what kind of address is this?" label 🎀. It's giving enum, and the big rule is that every concrete type needs its own textual convention, and the type and address have to be changed as a pair so nothing ends up undefined 💅 Sub-typing it in object definitions is a no-go, but compliance statements can narrow it down to a subset 🌸
InetAddress ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Denotes a generic Internet address.
An InetAddress value is always interpreted within the context
of an InetAddressType value. Every usage of the InetAddress
textual convention is required to specify the InetAddressType
object which provides the context. It is suggested that the
InetAddressType object is logically registered before the
object(s) which use the InetAddress textual convention if
they appear in the same logical row.
The value of an InetAddress object must always be
consistent with the value of the associated InetAddressType
object. Attempts to set an InetAddress object to a value
which is inconsistent with the associated InetAddressType
must fail with an inconsistentValue error.
When this textual convention is used as the syntax of an
index object, there may be issues with the limit of 128
sub-identifiers specified in SMIv2, STD 58. In this case,
the object definition MUST include a 'SIZE' clause to
limit the number of potential instance sub-identifiers."
SYNTAX OCTET STRING (SIZE (0..255))InetAddress is the generic address that only means something alongside its InetAddressType, so they're basically a couple 🫶 If you use it as an index, the object definition MUST include a 'SIZE' clause, because SMIv2 caps instance sub-identifiers at 128, and nobody wants that drama 😭
InetAddressIPv4 ::= TEXTUAL-CONVENTION
DISPLAY-HINT "1d.1d.1d.1d"
STATUS current
DESCRIPTION
"Represents an IPv4 network address:
octets contents encoding
1-4 IPv4 address network-byte order
The corresponding InetAddressType value is ipv4(1).
This textual convention SHOULD NOT be used directly in object
definitions since it restricts addresses to a specific format.
However, if it is used, it MAY be used either on its own or in
conjunction with InetAddressType as a pair."
SYNTAX OCTET STRING (SIZE (4))
InetAddressIPv6 ::= TEXTUAL-CONVENTION
DISPLAY-HINT "2x:2x:2x:2x:2x:2x:2x:2x"
STATUS current
DESCRIPTION
"Represents an IPv6 network address:
octets contents encoding
1-16 IPv6 address network-byte order
The corresponding InetAddressType value is ipv6(2).
This textual convention SHOULD NOT be used directly in object
definitions since it restricts addresses to a specific format.
However, if it is used, it MAY be used either on its own or in
conjunction with InetAddressType as a pair."
SYNTAX OCTET STRING (SIZE (16))The IPv4 and IPv6 ones are the straightforward fixed-size vibes 🦋 4 octets for IPv4, 16 for IPv6, both in network-byte order. The catch is they're a bit too rigid to use directly in object definitions, so you're encouraged to avoid them there, though you can still use them alone or paired with InetAddressType if you really need to 🙈
InetAddressIPv4z ::= TEXTUAL-CONVENTION
DISPLAY-HINT "1d.1d.1d.1d%4d"
STATUS current
DESCRIPTION
"Represents a non-global IPv4 network address together
with its zone index:
octets contents encoding
1-4 IPv4 address network-byte order
5-8 zone index network-byte order
The corresponding InetAddressType value is ipv4z(3).
The zone index (bytes 5-8) is used to disambiguate identical
address values on nodes which have interfaces attached to
different zones of the same scope. The zone index may contain
the special value 0 which refers to the default zone for each
scope.
This textual convention SHOULD NOT be used directly in object
definitions since it restricts addresses to a specific format.
However, if it is used, it MAY be used either on its own or in
conjunction with InetAddressType as a pair."
SYNTAX OCTET STRING (SIZE (8))
InetAddressIPv6z ::= TEXTUAL-CONVENTION
DISPLAY-HINT "2x:2x:2x:2x:2x:2x:2x:2x%4d"
STATUS current
DESCRIPTION
"Represents a non-global IPv6 network address together
with its zone index:
octets contents encoding
1-16 IPv6 address network-byte order
17-20 zone index network-byte order
The corresponding InetAddressType value is ipv6z(4).
The zone index (bytes 17-20) is used to disambiguate
identical address values on nodes which have interfaces
attached to different zones of the same scope. The zone index
may contain the special value 0 which refers to the default
zone for each scope.
This textual convention SHOULD NOT be used directly in object
definitions since it restricts addresses to a specific format.
However, if it is used, it MAY be used either on its own or in
conjunction with InetAddressType as a pair."
SYNTAX OCTET STRING (SIZE (20))The zoned versions are the "same address, different neighbourhood" situation 🌈 The zone index (bytes 5-8 for IPv4z, bytes 17-20 for IPv6z) is what tells identical addresses apart when a node is hooked up to different zones of the same scope. Zone index 0 is the special default zone for each scope 🧚 Same rules as before, though: avoid using them directly in object definitions, and if you do use them, it's on their own or paired with InetAddressType 💖
InetAddressDNS ::= TEXTUAL-CONVENTION
DISPLAY-HINT "255a"
STATUS current
DESCRIPTION
"Represents a DNS domain name. The name SHOULD be fully
qualified whenever possible.
The corresponding InetAddressType is dns(16).
The DESCRIPTION clause of InetAddress objects that may have
InetAddressDNS values must fully describe how (and when) such
names are to be resolved to IP addresses.
This textual convention SHOULD NOT be used directly in object
definitions since it restricts addresses to a specific format.
However, if it is used, it MAY be used either on its own or in
conjunction with InetAddressType as a pair."
SYNTAX OCTET STRING (SIZE (1..255))DNS names are the human-readable one 🍓 The name SHOULD be fully qualified whenever possible, and any InetAddress object that can hold a DNS value has to fully explain how and when that name gets resolved to an IP address. Same "don't use it directly in object definitions" warning applies, so keep it as a pair with InetAddressType if you use it 🫶
InetAddressPrefixLength ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Denotes the length of a generic Internet network address
prefix. A value of n corresponds to an IP address mask
which has n contiguous 1-bits from the most significant
bit (MSB) and all other bits set to 0.
An InetAddressPrefixLength value is always interpreted within
the context of an InetAddressType value. Every usage of the
InetAddressPrefixLength textual convention is required to
specify the InetAddressType object which provides the
context. It is suggested that the InetAddressType object is
logically registered before the object(s) which use the
InetAddressPrefixLength textual convention if they appear in
the same logical row.
InetAddressPrefixLength values that are larger than
the maximum length of an IP address for a specific
InetAddressType are treated as the maximum significant
value applicable for the InetAddressType. The maximum
significant value is 32 for the InetAddressType
'ipv4(1)' and 'ipv4z(3)' and 128 for the InetAddressType
'ipv6(2)' and 'ipv6z(4)'. The maximum significant value
for the InetAddressType 'dns(16)' is 0.
The value zero is object-specific and must be defined as
part of the description of any object which uses this
syntax. Examples of the usage of zero might include
situations where the Internet network address prefix
is unknown or does not apply."
SYNTAX Unsigned32The prefix length is the count of leading 1-bits in the mask 😭 Anything bigger than the max for your address type just gets clamped to that max, so 32 for IPv4 and 128 for IPv6, with DNS topping out at 0. Zero is a special case that each object has to define for itself, like when the prefix is unknown or doesn't apply 🎀
InetPortNumber ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Represents a 16 bit port number of an Internet transport
layer protocol. Port numbers are assigned by IANA. A
current list of all assignments is available from
<http://www.iana.org/>.
The value zero is object-specific and must be defined as
part of the description of any object which uses this
syntax. Examples of the usage of zero might include
situations where a port number is unknown, or when the
value zero is used as a wildcard in a filter."
REFERENCE "STD 6 (RFC 768), STD 7 (RFC 793) and RFC 2960"
SYNTAX Unsigned32 (0..65535)Port numbers are 16-bit values for transport protocols, and IANA is the one assigning them, with the current list at <http://www.iana.org/> 🦋 Zero is object-specific again, so whatever object uses it has to say what zero means, like "unknown" or "wildcard in a filter" 💅
InetAutonomousSystemNumber ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Represents an autonomous system number which identifies an
Autonomous System (AS). An AS is a set of routers under a
single technical administration, using an interior gateway
protocol and common metrics to route packets within the AS,
and using an exterior gateway protocol to route packets to
other ASs'. IANA maintains the AS number space and has
delegated large parts to the regional registries.
Autonomous system numbers are currently limited to 16 bits
(0..65535). There is however work in progress to enlarge the
autonomous system number space to 32 bits. This textual
convention therefore uses an Unsigned32 value without a
range restriction in order to support a larger autonomous
system number space."
REFERENCE "RFC 1771, RFC 1930"
SYNTAX Unsigned32
ENDAnd last but not least, the autonomous system number 👑 An AS is a group of routers under one technical administration, and IANA handles the AS number space and hands out big chunks to the regional registries 🌸 AS numbers were 16-bit at the time, but because a bigger space was being worked on, this convention uses Unsigned32 with no range restriction so it can hold the larger numbers too ✨
4. Usage Hints ✨
okay bestie, so the InetAddressType and InetAddress textual conventions exist so we don't over-constrain an object by using the IpAddress SMI base type, which is IPv4-only 🙄. An InetAddressType/InetAddress pair can represent IP addresses in all kinds of formats 🦋
The InetAddressType and InetAddress objects SHOULD NOT be sub-typed in object definitions 🚫. Sub-typing locks the MIB module to specific address formats, and that can cause serious problems if new address formats ever need to be introduced 💀. You can still write compliance statements saying only a subset of the defined address types must be implemented to be compliant, so you're not totally stuck ✨
Every usage of the InetAddress or InetAddressPrefixLength textual conventions must specify which InetAddressType object gives the context for interpreting them 🎀
It's suggested that the InetAddressType object gets logically registered before the object(s) that use the InetAddress or InetAddressPrefixLength textual convention 💅 An InetAddressType object counts as logically registered before an InetAddress or InetAddressPrefixLength object if it shows up before that object in the conceptual row (index objects included) 🧚 This is the rule that lets tools like MIB compilers find the InetAddressType for a given InetAddress or InetAddressPrefixLength object by searching backwards for the nearest InetAddressType object 🔍
4.1 Table Indexing
When a generic Internet address is used as an index, both the InetAddressType and InetAddress objects MUST be used 🙌 The InetAddressType object MUST be listed before the InetAddress object in the INDEX clause 📋
The IMPLIED keyword MUST NOT be used for an object of type InetAddress in an INDEX clause 🙅♀️ Instance sub-identifiers then look like T.N.O1.O2...On, where T is the value of the InetAddressType object, O1...On are the octets in the InetAddress object, and N is the number of those octets 🔢
Tables indexed this way have a meaningful lexicographical ordering, and that's honestly so iconic 😭 Command generator applications can look up specific addresses of a known type and value, issue GetNext requests for addresses of a single type, or issue GetNext requests for a specific type and address prefix 🌈
4.2 Uniqueness of Addresses
IPv4 addresses were intended to be globally unique, even though that's not how things are used today 🥲 IPv6 addresses were architected to have different scopes and hence uniqueness [19] 🌸 Specifically, IPv6 "link-local" and "site-local" addresses are not guaranteed to be unique on any particular node 🙈 In those cases, the duplicate addresses must be configured on different interfaces 🫶 So the combination of an IPv6 address and a zone index is what's unique [21] 💖
The InetAddressIPv6 textual convention is there to represent global IPv6 addresses and non-global IPv6 addresses where no zone index is needed (for example, on end hosts with a single interface) ✨ The InetAddressIPv6z textual convention is there to represent non-global IPv6 addresses where a zone index is needed (for example, a router connecting multiple zones) 👑 So MIB designers using InetAddressType/InetAddress pairs don't have to define extra objects to support non-global addresses on nodes that connect multiple zones 🙌
InetAddressIPv4z is meant for MIBs like the TCP-MIB 🦋 Those MIBs report addresses in the address family used on the wire, but the instrumented entity gets those addresses from applications or administrators in a form that includes a zone index, like v4-mapped IPv6 addresses 🧚
The size of the zone index was picked to stay consistent with (i) the numerical zone index defined in [21] and (ii) the sin6_scope_id field of the sockaddr_in6 structure defined in RFC 2553 [20] 🎀 Consistency is everything, periodt 💅
4.3 Multiple Addresses per Host
A single host system may be configured with multiple addresses (IPv4 or IPv6), and possibly with multiple DNS names 🌐 So a single host system can be reachable through multiple InetAddressType/InetAddress pairs 🍓
If this could be an implementation or usage issue, the DESCRIPTION clause of the relevant objects must fully describe which address is reported in a given InetAddressType/InetAddress pair 📝 Be clear, bestie 🫶
4.4 Resolving DNS Names
DNS names MUST be resolved to IP addresses when communication with the named host is required 🔎 This creates a timing question for MIB objects whose value is a DNS name: when does the name get translated into an address? ⏰
For example, say an object is defined to indicate a forwarding destination, and its value is a DNS name 🧭 When does the forwarding entity resolve that name? Every time forwarding happens, or just once when the object was instantiated? 🤔
The DESCRIPTION clause of such objects SHOULD precisely define how and when any required name-to-address resolution gets done 📖
Similarly, the DESCRIPTION clause of such objects SHOULD precisely define how and when a reverse lookup happens, in case an agent has accessed instrumentation that knows about an IP address and the MIB module or implementation needs to map that IP address to a DNS name 🔄 Spell it out, no vibes-only descriptions 💅
5. Table Indexing Example 🎀
This example shows a table listing communication peers that are identified by an IPv4 address, an IPv6 address, or a DNS name 🦋 The table definition also prohibits entries with an empty address (whose type would be "unknown") 🙅♀️ The size of a DNS name is limited to 64 characters so it fits within OID length constraints 🔢
peerTable OBJECT-TYPE
SYNTAX SEQUENCE OF PeerEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of communication peers."
::= { somewhere 1 }
peerEntry OBJECT-TYPE
SYNTAX PeerEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry containing information about a particular peer."
INDEX { peerAddressType, peerAddress }
::= { peerTable 1 }
PeerEntry ::= SEQUENCE {
peerAddressType InetAddressType,
peerAddress InetAddress,
peerStatus INTEGER
}
peerAddressType OBJECT-TYPE
SYNTAX InetAddressType
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The type of Internet address by which the peer
is reachable."
::= { peerEntry 1 }
peerAddress OBJECT-TYPE
SYNTAX InetAddress (SIZE (1..64))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The Internet address for the peer. The type of this
address is determined by the value of the peerAddressType
object. Note that implementations must limit themselves
to a single entry in this table per reachable peer.
The peerAddress may not be empty due to the SIZE
restriction.
If a row is created administratively by an SNMP
operation and the address type value is dns(16), then
the agent stores the DNS name internally. A DNS name
lookup must be performed on the internally stored DNS
name whenever it is being used to contact the peer.
If a row is created by the managed entity itself and
the address type value is dns(16), then the agent
stores the IP address internally. A DNS reverse lookup
must be performed on the internally stored IP address
whenever the value is retrieved via SNMP."
::= { peerEntry 2 }The following compliance statement says compliant implementations only need to support IPv4/IPv6 addresses without zone indices 🧁 Support for DNS names, or for IPv4/IPv6 addresses with zone indices, is not required 🙅♀️
peerCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement of the peer MIB."
MODULE -- this module
MANDATORY-GROUPS { peerGroup }
OBJECT peerAddressType
SYNTAX InetAddressType { ipv4(1), ipv6(2) }
DESCRIPTION
"An implementation is only required to support IPv4
and IPv6 addresses without zone indices."
::= { somewhere 2 }Note that SMIv2 doesn't permit not-accessible objects to be included in an object group (see section 3.1 in STD 58, RFC 2580 [8]) 🙃 So it isn't possible to formally refine the syntax of auxiliary objects that are not-accessible 😭 In that case, it's suggested to express the refinement informally in the DESCRIPTION clause of the MODULE-COMPLIANCE macro invocation 📝
6. Security Considerations 🔐
This module doesn't define any management objects 🙅♀️ Instead, it defines a set of textual conventions that other MIB modules can use to define management objects 📦
Meaningful security considerations can only be written in the MIB modules that define management objects 🛡️ This document therefore has no impact on the security of the Internet 🌍
Okay, real talk for a sec: the security stuff lives in the MIB modules that actually define the objects, not here. Go check those, bestie 🫶
7. Acknowledgments 💜
This document was produced by the Operations and Management Area "IPv6MIB" design team 🧚 The authors would like to thank Fred Baker, Randy Bush, Richard Draves, Mark Ellison, Bill Fenner, Jun-ichiro Hagino, Mike Heard, Tim Jenkins, Glenn Mansfield, Keith McCloghrie, Thomas Narten, Erik Nordmark, Peder Chr. Norgaard, Randy Presuhn, Andrew Smith, Dave Thaler, Kenneth White, Bert Wijnen, and Brian Zill for their comments and suggestions 🙌 Thank you all, you're literally the reason this is good 💖
8. Intellectual Property Notice ⚖️
The IETF takes no position on the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document, or on the extent to which any license under such rights might or might not be available 📜 It also doesn't represent that it has made any effort to identify any such rights 🔍 Information on the IETF's procedures for rights in standards-track and standards-related documentation can be found in BCP 11 📖 Copies of claims of rights made available for publication, any assurances of licenses to be made available, or the result of an attempt to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat 🗂️
The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard 🦋 Please send that information to the IETF Executive Director 💌
9. Changes from RFC 2851 ✨
okay, glow-up log time 💅 these are all the changes relative to RFC 2851:
- Added the new textual conventions
InetAddressPrefixLength,InetPortNumber, andInetAutonomousSystemNumber🎀 - Rewrote the intro to say clearly that, in general, you should define MIB tables that work with all versions of IP 🫶 The other approach of multiple tables for different IP versions is strongly discouraged 🙅
- Added text to the
InetAddressTypeandInetAddressdescriptions saying implementations must reject set operations with aninconsistentValueerror if they lead to inconsistencies 🚫 - Removed the strict ordering constraints ✂️ Description clauses now must explain which
InetAddressTypeobject provides the context for anInetAddressorInetAddressPrefixLengthobject 🧚 - Aligned the wording with the IPv6 scoping architecture document 💜
- Split the
InetAddressIPv6textual convention into two (InetAddressIPv6andInetAddressIPv6z) and introduced a brand new textual convention,InetAddressIPv4z🦋 Added theipv4z(3)andipv6z(4)named numbers to theInetAddressTypeenumeration. And why did we do all this? Four very good reasons 👑- (i) enable the introduction of textual conventions for non-global IPv4 addresses
- (ii) alignment with the textual conventions for transport addresses
- (iii) simpler compliance statements in cases where support for IPv6 addresses with zone indices is not required
- (iv) simpler implementations for host systems that will never have to report zone indices
References
Here's the reading list, bestie 📚🧚
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[2] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for Describing SNMP Management Frameworks", RFC 2571, April 1999.
[3] Rose, M. and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", STD 16, RFC 1155, May 1990.
[4] Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16, RFC 1212, March 1991.
[5] Rose, M., "A Convention for Defining Traps for use with the SNMP", RFC 1215, March 1991.
[6] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
[7] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999.
[8] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Conformance Statements for SMIv2", STD 58, RFC 2580, April 1999.
[9] Case, J., Fedor, M., Schoffstall, M. and J. Davin, "A Simple Network Management Protocol (SNMP)", STD 15, RFC 1157, May 1990.
[10] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Introduction to Community-based SNMPv2", RFC 1901, January 1996.
[11] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport Mappings for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1906, January 1996.
[12] Case, J., Harrington, D., Presuhn, R. and B. Wijnen, "Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)", RFC 2572, April 1999.
[13] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", RFC 2574, April 1999.
[14] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Protocol Operations for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1905, January 1996.
[15] Levi, D., Meyer, P. and B. Stewart, "SNMP Applications", RFC 2573, April 1999.
[16] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", RFC 2575, April 1999.
[17] Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction to Version 3 of the Internet-standard Network Management Framework", RFC 2570, April 1999.
[18] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB", RFC 2863, June 2000.
[19] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 2373, July 1998.
[20] Gilligan, R., Thomson, S., Bound, J. and W. Stevens, "Basic Socket Interface Extensions for IPv6", RFC 2553, March 1999.
[21] Deering, S., Haberman, B., Jinmei, T., Nordmark, E., Onoe, A. and B. Zill, "IPv6 Scoped Address Architecture", Work in Progress.
Authors' Addresses
Meet the squad 🌸
Mike Daniele
Consultant
19 Pinewood Rd
Hudson, NH 03051
USA
Phone: +1 603 883-6365
EMail: md@world.std.com
Brian Haberman
Phone: +1 919 949-4828
EMail: bkhabs@nc.rr.com
Shawn A. Routhier
Wind River Systems, Inc.
500 Wind River Way
Alameda, CA 94501
USA
Phone: +1 510 749 2095
EMail: sar@epilogue.com
Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Phone: +49 531 391-3289
EMail: schoenw@ibr.cs.tu-bs.deFull Copyright Statement
Now the legal stuff, which we keep exactly as written 🙏⚖️
Copyright (C) The Internet Society (2002). All Rights Reserved.
This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.
The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgement
Funding for the RFC Editor function is currently provided by the Internet Society. 🫶
📦 where this page comes from
- ietf: rfc3291 2002-05
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms