Internet DRAFT - draft-ietf-snmp-mib-table
draft-ietf-snmp-mib-table
T. Pusateri
INTERNET DRAFT Consultant
Expiration date: September 1993 June 1993
Managed Objects for the IP Multicast Forwarding Table
1. 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 the IP Multicast Forwarding
Table. IP Multicast Extensions are defined in RFC 1112 [1].
2. Status of this Memo
This document will be submitted to the RFC editor as an extension to the
SNMP MIB. Distribution of this memo is unlimited. Please send comments
to the authors.
This document is an Internet Draft. Internet Drafts are working
documents of the Internet Engineering Task Force (IETF), its Areas, and
its Working Groups. Note that other groups may also distribute working
documents as Internet Drafts.
Internet Drafts are draft documents valid for a maximum of six months.
Internet Drafts may be updated, replaced, or obsoleted by other
documents at any time. It is not appropriate to use Internet Drafts as
reference material or to cite them other than as a "working draft" or
"work in progress."
Please check the I-D abstract listing contained in each Internet Draft
directory to learn the current status of this or any other Internet
Draft.
3. The Network Management Framework
The Internet-standard Network Management Framework consists of three
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components. They are:
RFC 1155 [2]
which defines the SMI, the mechanisms used for describing and
naming objects for the purpose of management. RFC 1212 [3] 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. RFC 1213 [5], defines MIB-II, an
evolution of MIB-I based on implementation experience and new
operational requirements.
RFC 1157 [6]
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.
4. 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 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
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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.
Format of Definitions
Section 6 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 RFC1212.
5. Overview
The IP multicast forwarding mib is intended to provide a protocol
independent method to monitor the IP multicast forwarding cache.
Protocol dependent information (such as tunnels) should be stored in a
protocol specific mib pointed to by ipMulticastForwardInfo.
Each forwarding cache entry is identified by a Group Address, Source
Network pair. The Source Network is described by the
ipMulticastForwardSourceNet and ipMulticastForwardSourceMask variables.
Each entry is also indexed by ipMulticastForwardPolicy to allow for
different TOS requirements.
For each entry there is an upstream interface and (downstream interface,
TTL) pairs. This requires that the table be indexed by
ipMultiDownstreamIfIndex to allow for forwarding the multicast datagram
out multiple interfaces if they lie on the shortest path multicast tree.
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6. Definitions
IPMULTI-FORWARDING-MIB DEFINITIONS ::= BEGIN
IMPORTS
IpAddress, Counter, Gauge, experimental
FROM RFC1155-SMI
OBJECT-TYPE
FROM RFC-1212;
-- This MIB module defines an information base for the
-- IP Multicast Forwarding Table.
-- It is based on the specification found in RFC 1112.
-- Please send any comments to Tom Pusateri (pusateri@cs.duke.edu).
-- Thanks to John Moy and Greg Minshall for their review and comments.
-- $Id: ipmultiforward.mib,v 1.5 1993/06/23 02:19:47 pusateri Exp $
ipMulticastForward OBJECT IDENTIFIER ::= { experimental xxx }
ipMulticastForwarding OBJECT-TYPE
SYNTAX INTEGER {
forwarding(1), -- acting as a multicast router
not-forwarding(2) -- NOT acting as a multicast router
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The indication of whether this entity is acting as
an IP Multicast gateway in respect to the forwarding
of CLASS D datagrams received by this entity."
::= { ipMulticastForward 1 }
ipMulticastForwardNumber OBJECT-TYPE
SYNTAX Gauge
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of current ipMulticastForwardTable entries
that are not invalid."
::= { ipMulticastForward 2 }
-- IP Multicast Forwarding Table
ipMulticastForwardTable OBJECT-TYPE
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SYNTAX SEQUENCE OF IpMulticastForwardEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"This entity's IP Multicast forwarding table."
::= { ipMulticastForward 3 }
ipMulticastForwardEntry OBJECT-TYPE
SYNTAX IpMulticastForwardEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A forwarding entry based on source network/destination
group under a particular policy."
INDEX {
ipMulticastForwardGroup,
ipMulticastForwardSourceNet,
ipMulticastForwardSourceMask,
ipMulticastForwardPolicy,
ipMultiDownstreamIfIndex
}
::= { ipMulticastForwardTable 1 }
IpMulticastForwardEntry ::=
SEQUENCE {
ipMulticastForwardGroup
IpAddress,
ipMulticastForwardSourceNet
IpAddress,
ipMulticastForwardSourceMask
IpAddress,
ipMultiUpstreamIfIndex
INTEGER,
ipMultiDownstreamIfIndex
INTEGER,
ipMultiDownstreamTTL
INTEGER,
ipMulticastForwardProto
INTEGER,
ipMulticastForwardPolicy
INTEGER,
ipMulticastForwardAge
INTEGER,
ipMulticastForwardedDatagrams
Counter,
ipMulticastForwardInfo
OBJECT IDENTIFIER
}
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ipMulticastForwardGroup OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The destination IP Multicast Group Address. The
range of this address is defined in RFC 1112. It
is also referred to as a Class D address."
::= { ipMulticastForwardEntry 1 }
ipMulticastForwardSourceNet OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The source address of the IP Mulicast datagram.
This is required for Multicast Routing Protocol
performing Reverse Path Forwarding."
::= { ipMulticastForwardEntry 2 }
ipMulticastForwardSourceMask OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The source network mask of the IP Mulicast datagram.
This is required for Multicast Routing Protocol
performing Reverse Path Forwarding to uniquely
identify the source network."
::= { ipMulticastForwardEntry 3 }
ipMultiUpstreamIfIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"This value is a unique integer for each interface as
identified by the same value of IfIndex. It specifies
the interface an IP Multicast datagram is required to
be received on in order to be forwarded to the
downstream interface in the same entry of this table."
::= { ipMulticastForwardEntry 4 }
ipMultiDownstreamIfIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
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"This value is a unique integer for each interface as
identified by the same value of IfIndex. It specifies
the interface an IP Multicast datagram should be
forwarded out of given that it was received on the
upstream interface in the same entry of this table.
Before forwarding occurs, the datagram's TTL field
must also be greater than or equal to the TTL field
in the same entry of this table."
::= { ipMulticastForwardEntry 5 }
ipMultiDownstreamTTL OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The required minimum TTL for an IP Multicast Datagram
to reach the closest group member. If the TTL value
in the IP header of the IP Multicast datagram is not
at least this large, there is no reason to further
forward the datagram. This field is frequently used
for locating resources using the expanding ring search."
::= { ipMulticastForwardEntry 6 }
ipMulticastForwardProto OBJECT-TYPE
SYNTAX INTEGER {
other (1), -- not specified
local (2), -- local interface
netmgmt (3), -- static route
dvmrp (4), -- Distance Vector Multicast Routing
mospf (5) -- Multicast Open Shortest Path First
}
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The routing mechanism via which this route was
learned."
::= { ipMulticastForwardEntry 7 }
ipMulticastForwardPolicy OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The general set of conditions that would cause
the selection of one multipath route (set of
next hops for a given destination) is referred
to as 'policy'.
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Unless the mechanism indicated by ipForwardProto
specifies otherwise, the policy specifier is the
IP TOS Field. The encoding of IP TOS is as
specified by the following convention. Zero
indicates the default path if no more specific
policy applies.
+-----+-----+-----+-----+-----+-----+-----+-----+
| | | |
| PRECEDENCE | TYPE OF SERVICE | 0 |
| | | |
+-----+-----+-----+-----+-----+-----+-----+-----+
IP TOS IP TOS
Field Policy Field Policy
Contents Code Contents Code
0 0 0 0 ==> 0 0 0 0 1 ==> 2
0 0 1 0 ==> 4 0 0 1 1 ==> 6
0 1 0 0 ==> 8 0 1 0 1 ==> 10
0 1 1 0 ==> 12 0 1 1 1 ==> 14
1 0 0 0 ==> 16 1 0 0 1 ==> 18
1 0 1 0 ==> 20 1 0 1 1 ==> 22
1 1 0 0 ==> 24 1 1 0 1 ==> 26
1 1 1 0 ==> 28 1 1 1 1 ==> 30
Protocols defining 'policy' otherwise must either
define a set of values which are valid for this
object or must implement an integer-instanced
policy table for which this object's value acts
as an index."
::= { ipMulticastForwardEntry 8 }
ipMulticastForwardAge OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of seconds since this route was
last updated or otherwise determined to be
correct. Note that no semantics of `too old'
can be implied except through knowledge of the
routing protocol by which the route was
learned."
DEFVAL { 0 }
::= { ipMulticastForwardEntry 9 }
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ipMulticastForwardedDatagrams OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of IP Multicast datagrams that have
been forwarded from the upstream interface listed
in this entry to the downstream interface listed
in this entry. Note that because there could be
multiple downstream interfaces in this table for
the same (source network, destination group), this
number may not be the same as the number of
IP multicast datagrams received on the upstream
interface for a particular (source network, destination
group)."
::= { ipMulticastForwardEntry 10 }
ipMulticastForwardInfo OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"A reference to MIB definitions specific to the
particular routing protocol which is responsible
for this route, as determined by the value specified
in the route's ipMulticastForwardProto value. If
this information is not present, its value
should be set to the OBJECT IDENTIFIER { 0 0 },
which is a syntactically valid object identifier,
and any implementation conforming to ASN.1
and the Basic Encoding Rules must be able to
generate and recognize this value."
DEFVAL { { 0 0 } } -- 0.0
::= { ipMulticastForwardEntry 11 }
END
7. Acknowledgments
The author would like to thank John Moy and Greg Minshall for their
review and constructive comments.
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Author's Address:
Thomas J. Pusateri
Consultant
11820 Edgewater Ct.
Raleigh, NC 27614
pusateri@cs.duke.edu
8.0 References
[1] S. Deering, Host Extensions for IP Multicasting, Internet Working
Group Request for Comments 1112. Network Information Center, SRI
International, Menlo Park, California, (Aug, 1989).
[2] M.T. Rose and K. McCloghrie, Structure and Identification of
Management Information for TCP/IP-based internets, Internet Working
Group Request for Comments 1155. Network Information Center, SRI
International, Menlo Park, California, (May, 1990).
[3] M.T. Rose, Concise MIB definitions Internet Working Group Request
for Comments 1212. Network Information Center, SRI International,
Menlo Park, California, (March, 1991).
[4] K. McCloghrie and M.T. Rose, Management Information Base for
Network Management of TCP/IP-based internets, Internet Working
Group Request for Comments 1156. Network Information Center, SRI
International, Menlo Park, California, (May, 1990).
[5] M.T. Rose (editor), Management Information Base for Network
Management of TCP/IP-based internets, Internet Working Group
Request for Comments 1213. Network Information Center, SRI
International, Menlo Park, California, (March, 1991).
[6] J.D. Case, M.S. Fedor, M.L. Schoffstall, and J.R. Davin, Simple
Network Management Protocol, Internet Working Group Request for
Comments 1157. Network Information Center, SRI International,
Menlo Park, California, (May, 1990).
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[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).
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