Network Working Group N. Brownlee
Request for Comments: 2720 The University of AUCkland
Obsoletes: 2064 October 1999
Category: Standards Track
Traffic Flow Measurement: Meter MIB
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1999). All Rights Reserved.
Abstract
The RTFM Traffic Measurement Architecture provides a general
framework for describing and measuring network traffic flows. Flows
are defined in terms of their Address Attribute values and measured
by a 'Traffic Meter'.
This document defines a Management Information Base (MIB) for use in
controlling an RTFM Traffic Meter, in particular for specifying the
flows to be measured. It also provides an efficient mechanism for
retrieving flow data from the meter using SNMP. Security issues
concerning the operation of traffic meters are summarised.
Table of Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 The SNMP Management Framework . . . . . . . . . . . . . . . . 2
3 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1 Scope of Definitions, Textual Conventions . . . . . . . . . 4
3.2 Usage of the MIB variables . . . . . . . . . . . . . . . . 4
4 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 Security Considerations . . . . . . . . . . . . . . . . . . . . 46
5.1 SNMP Concerns . . . . . . . . . . . . . . . . . . . . . . 46
5.2 Traffic Meter Concerns . . . . . . . . . . . . . . . . . . 46
6 IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 48
7 Appendix A: Changes Introduced Since RFC2064 . . . . . . . . . 49
8 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 50
9 Intellectual Property Notice . . . . . . . . . . . . . . . . . 50
10 References . . . . . . . . . . . . . . . . . . . . . . . . . . 50
11 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 53
12 Full Copyright Statement . . . . . . . . . . . . . . . . . . . 54
1 Introduction
This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols in the Internet community.
In particular, it describes objects for managing and collecting data
from network Realtime Traffic Flow Meters, as described in [RTFM-
ARC].
The MIB is 'basic' in the sense that it provides more than enough
information for everyday traffic measurment. Furthermore, it can be
easily extended by adding new attributes as required. The RTFM
Working group is actively pursuing the development of the meter in
this way.
2 The SNMP Management Framework
The SNMP Management Framework presently consists of five major
components:
- An overall architecture, described in RFC2571 [RFC2571].
- 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 described in STD
16, RFC1155 [RFC1155], STD 16, RFC1212 [RFC1212] and RFC1215
[RFC1215]. The second version, called SMIv2, is described in STD
58, RFC2578 [RFC2578], RFC2579 [RFC2579] and RFC2580 [RFC2580].
- Message protocols for transferring management information. The
first version of the SNMP message protocol is called SNMPv1 and
described in STD 15, RFC1157 [RFC1157]. A second version of the
SNMP message protocol, which is not an Internet standards track
protocol, is called SNMPv2c and described in RFC1901 [RFC1901] and
RFC1906 [RFC1906]. The third version of the message protocol is
called SNMPv3 and described in RFC1906 [RFC1906], RFC2572
[RFC2572] and RFC2574 [RFC2574].
- Protocol operations for Accessing management information. The
first set of protocol operations and associated PDU formats is
described in STD 15, RFC1157 [RFC1157]. A second set of protocol
operations and associated PDU formats is described in RFC1905
[RFC1905].
- A set of fundamental applications described in RFC2573 [RFC2573]
and the view-based access control mechanism described in RFC2575
[RFC2575].
A more detailed introduction to the current SNMP Management Framework
can be found in [RFC2570].
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 Overview
Traffic Flow Measurement seeks to provide a well-defined method for
gathering traffic flow information from networks and internetworks.
The background for this is given in "Internet Accounting Background"
[ACT-BKG]. The Realtime Traffic Flow Measurement (rtfm) Working Group
has produced a measurement architecture to achieve this goal; this is
documented in "Traffic Flow Measurement: Architecture" [RTFM-ARC].
The architecture defines three entities:
- METERS, which observe network traffic flows and build up a table of
flow data records for them,
- METER READERS, which collect traffic flow data from meters, and
- MANAGERS, which oversee the operation of meters and meter readers.
This memo defines the SNMP management information for a Traffic Flow
Meter (TFM). Work in this field was begun by the Internet Accounting
Working Group. It has been further developed and eXPanded by the
Realtime Traffic Flow Measurement Working Group.
3.1 Scope of Definitions, Textual Conventions
All objects defined in this memo are registered in a single suBTree
within the mib-2 namespace [MIB-II, RFC2578], and are for use in
network devices which may perform a PDU forwarding or monitoring
function. For these devices, this MIB defines a group of objects
with an SMI Network Management MGMT Code [ASG-NBR] of 40, i.e.
flowMIB OBJECT IDENTIFIER ::= mib-2 40
as defined below.
The RTFM Meter MIB was first produced and tested using SNMPv1. It
was converted into SNMPv2 following the guidelines in [RFC1908].
3.2 Usage of the MIB variables
The MIB is organised in four parts - control, data, rules and
conformance statements.
The rules implement the set of packet-matching actions, as described
in the "Traffic Flow Measurment: Architecture" document [RTFM-ARC].
In addition they provide for BASIC-style subroutines, allowing a
network manager to dramatically reduce the number of rules required
to monitor a large network.
Traffic flows are identified by a set of attributes for each of their
end-points. Attributes include network addresses for each layer of
the network protocol stack, and 'subscriber ids', which may be used
to identify an accountable entity for the flow.
The conformance statements are set out as defined in [RFC2580]. They
explain what must be implemented in a meter which claims to conform
to this MIB.
To retrieve flow data one could simply do a linear scan of the flow
table. This would certainly work, but would require a lot of
protocol exchanges. To reduce the overhead in retrieving flow data
the flow table uses a TimeFilter variable, defined as a Textual
Convention in the RMON2 MIB [RMON2-MIB].
As an alternative method of reading flow data, the MIB provides a
view of the flow table called the flowDataPackageTable. This is
(logically) a four-dimensional array, subscripted by package
selector, RuleSet, activity time and starting flow number. The
package selector is a sequence of bytes which specifies a list of
flow attributes.
A data package (as returned by the meter) is a sequence of values for
the attributes specified in its selector, encoded using the Basic
Encoding Rules [ASN-BER]. It allows a meter reader to retrieve all
the attribute values it requires in a single MIB object. This, when
used together with SNMPv2's GetBulk request, allows a meter reader to
scan the flow table and upload a specified set of attribute values
for flows which have changed since the last reading, and which were
created by a specified rule set.
One ASPect of data collection which needs emphasis is that all the
MIB variables are set up to allow multiple independent meter readers
to work properly, i.e. the flow table indexes are stateless. An
alternative approach would have been to 'snapshot' the flow table,
which would mean that the meter readers would have to be
synchronized. The stateless approach does mean that two meter
readers will never return exactly the same set of traffic counts, but
over long periods (e.g. 15-minute collections over a day) the
discrepancies are acceptable. If one really needs a snapshot, this
can be achieved by switching to an identical rule set with a
different RuleSet number, hence asynchronous collections may be
regarded as a useful generalisation of synchronised ones.
The control variables are the minimum set required for a meter
reader. Their number has been whittled down as experience has been
gained with the MIB implementation. A few of them are 'general',
i.e. they control the overall behaviour of the meter. These are set
by a single 'master' manager, and no other manager should attempt to
change their values. The decision as to which manager is the '
master' must be made by the network operations personnel responsible;
this MIB does not attempt to define any interaction between managers.
There are three other groups of control variables, arranged into
tables in the same way as in the RMON2 MIB [RMON2-MIB]. They are used
as follows:
- RULE SET INFO: Before attempting to download a RuleSet, a manager
must create a row in the flowRuleSetInfoTable and set its
flowRuleInfoSize to a value large enough to hold the RuleSet. When
the rule set is ready the manager must set flowRuleInfoRulesReady
to 'true', indicating that the rule set is ready for use (but not
yet 'running').
- METER READER INFO: Any meter reader wishing to collect data
reliably for all flows from a RuleSet should first create a row in
the flowReaderInfoTable with flowReaderRuleSet set to that
RuleSet's index in the flowRuleSetInfoTable. It should write that
row's flowReaderLastTime object each time it starts a collection
pass through the flow table. The meter will not recover a flow's
memory until every meter reader holding a row for that flow's
RuleSet has collected the flow's data.
- MANAGER INFO: Any manager wishing to run a RuleSet in the meter
must create a row in the flowManagerInfo table, specifying the
desired RuleSet to run and its corresponding 'standby' RuleSet (if
one is desired). A current RuleSet is 'running' if its
flowManagerRunningStandby value is false(2), similarly a standby
RuleSet is 'running' if flowManagerRunningStandby is true(1).
Times within the meter are in terms of its Uptime, i.e. centiseconds
since the meter started. For meters implemented as self-contained
SNMP agents this will be the same as sysUptime, but this may not be
true for meters implemented as subagents. Managers can read the
meter's Uptime when neccessary (e.g. to set a TimeFilter value) by
setting flowReaderLastTime, then reading its new value.
4 Definitions
FLOW-METER-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE,
Counter32, Counter64, Integer32, mib-2
FROM SNMPv2-SMI
TEXTUAL-CONVENTION, RowStatus, TimeStamp, TruthValue
FROM SNMPv2-TC
OBJECT-GROUP, MODULE-COMPLIANCE
FROM SNMPv2-CONF
ifIndex
FROM IF-MIB
TimeFilter
FROM RMON2-MIB;
flowMIB MODULE-IDENTITY
LAST-UPDATED "9910250000Z" -- October 25, 1999
ORGANIZATION "IETF Realtime Traffic Flow Measurement Working Group"
CONTACT-INFO
"Nevil Brownlee, The University of Auckland
Postal: Information Technology Sytems & Services
The University of Auckland
Private Bag 92-019
Auckland, New Zealand
Phone: +64 9 373 7599 x8941
E-mail: n.brownlee@auckland.ac.nz"
DESCRIPTION
"MIB for the RTFM Traffic Flow Meter."
REVISION "9910250000Z"
DESCRIPTION
"Initial Version, published as RFC2720."
REVISION "9908301250Z"
DESCRIPTION
"UTF8OwnerString Textual Convention added, and used to
replace OwnerString. Conceptually the same as OwnerString,
but facilitating internationalisation by using UTF-8
encoding for its characters rather than US-ASCII."
REVISION "9908191010Z"
DESCRIPTION
"Changes to SIZE specification for two variables:
- flowRuleInfoName SIZE specified as (0..127)
- flowRuleIndex SIZE increased to (1..2147483647)"
REVISION "9712230937Z"
DESCRIPTION
"Two further variables deprecated:
- flowRuleInfoRulesReady (use flowRuleInfoStatus intead)
- flowDataStatus (contains no useful information)"
REVISION "9707071715Z"
DESCRIPTION
"Significant changes since RFC2064 include:
- flowDataPackageTable added
- flowColumnActivityTable deprecated
- flowManagerCounterWrap deprecated"
REVISION "9603080208Z"
DESCRIPTION
"Initial version of this MIB (RFC2064)"
::= { mib-2 40 }
flowControl OBJECT IDENTIFIER ::= { flowMIB 1 }
flowData OBJECT IDENTIFIER ::= { flowMIB 2 }
flowRules OBJECT IDENTIFIER ::= { flowMIB 3 }
flowMIBConformance OBJECT IDENTIFIER ::= { flowMIB 4 }
-- Textual Conventions
UTF8OwnerString ::= TEXTUAL-CONVENTION
DISPLAY-HINT "127t"
STATUS current
DESCRIPTION
"An administratively assigned name for the owner of a
resource, conceptually the same as OwnerString in the RMON
MIB [RMON-MIB].
To facilitate internationalisation, this name information
is represented using the ISO/IEC IS 10646-1 character set,
encoded as an octet string using the UTF-8 transformation
format described in the UTF-8 standard [UTF-8]."
SYNTAX OCTET STRING (SIZE (0..127))
PeerType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Indicates the type of a PeerAddress (see below). The values
used are from the 'Address Family Numbers' section of the
Assigned Numbers RFC[ASG-NBR]. Peer types from other address
families may also be used, provided only that they are
identified by their assigned Address Family numbers."
SYNTAX INTEGER {
ipv4(1),
ipv6(2),
nsap(3),
ipx(11),
appletalk(12),
decnet(13) }
PeerAddress ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Specifies the value of a peer address for various network
protocols. Address format depends on the actual protocol,
as indicated below:
IPv4: ipv4(1)
4-octet IpAddress (defined in the SNMPv2 SMI [RFC2578])
IPv6: ipv6(2)
16-octet IpAddress (defined in the
IPv6 Addressing RFC[V6-ADDR])
CLNS: nsap(3)
NsapAddress (defined in the SNMPv2 SMI [RFC2578])
Novell: ipx(11)
4-octet Network number,
6-octet Host number (MAC address)
AppleTalk: appletalk(12)
2-octet Network number (sixteen bits),
1-octet Host number (eight bits)
DECnet: decnet(13)
1-octet Area number (in low-order six bits),
2-octet Host number (in low-order ten bits)
"
SYNTAX OCTET STRING (SIZE (3..20))
AdjacentType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Indicates the type of an adjacent address. May be a medium
type or (if metering is taking place inside a tunnel) a
PeerType (see above).
The values used for IEEE 802 medium types are from the 'Network
Management Parameters (ifType definitions)' section of the
Assigned Numbers RFC[ASG-NBR]. Other medium types may also
be used, provided only that they are identified by their
assigned ifType numbers."
SYNTAX INTEGER {
ip(1),
nsap(3),
ethernet(7), -- ethernet-like [ENET-OBJ],
-- includes ethernet-csmacd(6)
tokenring(9),
ipx(11),
appletalk(12),
decnet(13),
fddi(15) }
AdjacentAddress ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Specifies the value of an adjacent address. May be a Medium
Access Control (MAC) address or (if metering is taking place
inside a tunnel) a PeerAddress (see above).
MAC Address format depends on the actual medium, as follows:
Ethernet: ethernet(7)
6-octet 802.3 MAC address in 'canonical' order
Token Ring: tokenring(9)
6-octet 802.5 MAC address in 'canonical' order
FDDI: fddi(15)
FddiMACLongAddress, i.e. a 6-octet MAC address
in 'canonical' order (defined in [FDDI-MIB])
"
SYNTAX OCTET STRING (SIZE (3..20))
TransportType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Indicates the type of a TransportAddress (see below). Values
will depend on the actual protocol; for IP they will be those
given in the 'Protocol Numbers' section of the Assigned Numbers
RFC[ASG-NBR], including icmp(1), tcp(6) and udp(17)."
SYNTAX Integer32 (1..255)
TransportAddress ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Specifies the value of a transport address for various
network protocols. Format as follows:
IP:
2-octet UDP or TCP port number
Other protocols:
2-octet port number
"
SYNTAX OCTET STRING (SIZE (2))
RuleAddress ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Specifies the value of an address. Is a superset of
MediumAddress, PeerAddress and TransportAddress."
SYNTAX OCTET STRING (SIZE (2..20))
FlowAttributeNumber ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Uniquely identifies an attribute within a flow data record."
SYNTAX INTEGER {
flowIndex(1),
flowStatus(2),
flowTimeMark(3),
sourceInterface(4),
sourceAdjacentType(5),
sourceAdjacentAddress(6),
sourceAdjacentMask(7),
sourcePeerType(8),
sourcePeerAddress(9),
sourcePeerMask(10),
sourceTransType(11),
sourceTransAddress(12),
sourceTransMask(13),
destInterface(14),
destAdjacentType(15),
destAdjacentAddress(16),
destAdjacentMask(17),
destPeerType(18),
destPeerAddress(19),
destPeerMask(20),
destTransType(21),
destTransAddress(22),
destTransMask(23),
pduScale(24),
octetScale(25),
ruleSet(26),
toOctets(27), -- Source-to-Dest
toPDUs(28),
fromOctets(29), -- Dest-to-Source
fromPDUs(30),
firstTime(31), -- Activity times
lastActiveTime(32),
sourceSubscriberID(33), -- Subscriber ID
destSubscriberID(34),
sessionID(35),
sourceClass(36), -- Computed attributes
destClass(37),
flowClass(38),
sourceKind(39),
destKind(40),
flowKind(41) }
RuleAttributeNumber ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Uniquely identifies an attribute which may be tested in
a rule. These include attributes whose values come directly
from (or are computed from) the flow's packets, and the five
'meter' variables used to hold an Attribute Number."
SYNTAX INTEGER {
null(0),
sourceInterface(4), -- Source Address
sourceAdjacentType(5),
sourceAdjacentAddress(6),
sourcePeerType(8),
sourcePeerAddress(9),
sourceTransType(11),
sourceTransAddress(12),
destInterface(14), -- Dest Address
destAdjacentType(15),
destAdjacentAddress(16),
destPeerType(18),
destPeerAddress(19),
destTransType(21),
destTransAddress(22),
sourceSubscriberID(33), -- Subscriber ID
destSubscriberID(34),
sessionID(35),
sourceClass(36), -- Computed attributes
destClass(37),
flowClass(38),
sourceKind(39),
destKind(40),
flowKind(41),
matchingStoD(50), -- Packet matching
v1(51), -- Meter variables
v2(52),
v3(53),
v4(54),
v5(55) }
ActionNumber ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Uniquely identifies the action of a rule, i.e. the Pattern
Matching Engine's opcode number. Details of the opcodes
are given in the 'Traffic Flow Measurement: Architecture'
document [RTFM-ARC]."
SYNTAX INTEGER {
ignore(1),
noMatch(2),
count(3),
countPkt(4),
return(5),
gosub(6),
gosubAct(7),
assign(8),
assignAct(9),
goto(10),
gotoAct(11),
pushRuleTo(12),
pushRuleToAct(13),
pushPktTo(14),
pushPktToAct(15),
popTo(16),
popToAct(17) }
--
-- Control Group: RuleSet Info Table
--
flowRuleSetInfoTable OBJECT-TYPE
SYNTAX SEQUENCE OF FlowRuleSetInfoEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An array of information about the RuleSets held in the
meter.
Any manager may configure a new RuleSet for the meter by
creating a row in this table with status active(1), and setting
values for all the objects in its rules. At this stage the new
RuleSet is available but not 'running', i.e. it is not being
used by the meter to produce entries in the flow table.
To actually 'run' a RuleSet a manager must create a row in
the flowManagerInfoTable, set it's flowManagerStatus to
active(1), and set either its CurrentRuleSet or StandbyRuleSet
to point to the RuleSet to be run.
Once a RuleSet is running a manager may not change any of the
objects within the RuleSet itself. Any attempt to do so should
result in a notWritable(17) SNMP error-status for such objects.
A manager may stop a RuleSet running by removing all
references to it in the flowManagerInfoTable (i.e. by setting
CurrentRuleSet and StandbyRuleSet values to 0). This provides
a way to stop RuleSets left running if a manager fails.
For example, when a manager is started, it could search the
meter's flowManager table and stop all RuleSets having a
specified value of flowRuleInfoOwner.
To prevent a manager from interfering with variables belonging
to another manager, the meter should use MIB views [RFC2575] so
as to limit each manager's access to the meter's variables,
effectively dividing the single meter into several virtual
meters, one for each independent manager."
::= { flowControl 1 }
flowRuleSetInfoEntry OBJECT-TYPE
SYNTAX FlowRuleSetInfoEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Information about a particular RuleSet."
INDEX { flowRuleInfoIndex }
::= { flowRuleSetInfoTable 1 }
FlowRuleSetInfoEntry ::= SEQUENCE {
flowRuleInfoIndex Integer32,
flowRuleInfoSize Integer32,
flowRuleInfoOwner UTF8OwnerString,
flowRuleInfoTimeStamp TimeStamp,
flowRuleInfoStatus RowStatus,
flowRuleInfoName OCTET STRING,
flowRuleInfoRulesReady TruthValue,
flowRuleInfoFlowRecords Integer32
}
flowRuleInfoIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index which selects an entry in the flowRuleSetInfoTable.
Each such entry contains control information for a particular
RuleSet which the meter may run."
::= { flowRuleSetInfoEntry 1 }
flowRuleInfoSize OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Number of rules in this RuleSet. Setting this variable will
cause the meter to allocate space for these rules."
::= { flowRuleSetInfoEntry 2 }
flowRuleInfoOwner OBJECT-TYPE
SYNTAX UTF8OwnerString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Identifies the manager which 'owns' this RuleSet. A manager
must set this variable when creating a row in this table."
::= { flowRuleSetInfoEntry 3 }
flowRuleInfoTimeStamp OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Time this row's associated RuleSet was last changed."
::= { flowRuleSetInfoEntry 4 }
flowRuleInfoStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this flowRuleSetInfoEntry. If this value is
not active(1) the meter must not attempt to use the row's
associated RuleSet. Once its value has been set to active(1)
a manager may not change any of the other variables in the
row, nor the contents of the associated RuleSet. Any attempt
to do so should result in a notWritable(17) SNMP error-status
for such variables or objects.
To download a RuleSet, a manger could:
- Locate an open slot in the RuleSetInfoTable.
- Create a RuleSetInfoEntry by setting the status for this
open slot to createAndWait(5).
- Set flowRuleInfoSize and flowRuleInfoName as required.
- Download the rules into the row's rule table.
- Set flowRuleInfoStatus to active(1).
The RuleSet would then be ready to run. The manager is not
allowed to change the value of flowRuleInfoStatus from
active(1) if the associated RuleSet is being referenced by any
of the entries in the flowManagerInfoTable.
Setting RuleInfoStatus to destroy(6) destroys the associated
RuleSet together with any flow data collected by it."
::= { flowRuleSetInfoEntry 5 }
flowRuleInfoName OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (0..127))
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An alphanumeric identifier used by managers and readers to
identify a RuleSet. For example, a manager wishing to run a
RuleSet named WWW-FLOWS could search the flowRuleSetInfoTable
to see whether the WWW-FLOWS RuleSet is already available on
the meter.
Note that references to RuleSets in the flowManagerInfoTable
use indexes for their flowRuleSetInfoTable entries. These may
be different each time the RuleSet is loaded into a meter."
::= { flowRuleSetInfoEntry 6 }
flowRuleInfoRulesReady OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-create
STATUS deprecated
DESCRIPTION
"Indicates whether the rules for this row's associated RuleSet
are ready for use. The meter will refuse to 'run' the RuleSet
unless this variable has been set to true(1).
While RulesReady is false(2), the manager may modify the
RuleSet, for example by downloading rules into it."
::= { flowRuleSetInfoEntry 7 }
flowRuleInfoFlowRecords OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of entries in the flow table for this RuleSet.
These may be current (waiting for collection by one or more
meter readers) or idle (waiting for the meter to recover
their memory)."
::= { flowRuleSetInfoEntry 8 }
--
-- Control Group: Interface Info Table
--
flowInterfaceTable OBJECT-TYPE
SYNTAX SEQUENCE OF FlowInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An array of information specific to each meter interface."
::= { flowControl 2 }
flowInterfaceEntry OBJECT-TYPE
SYNTAX FlowInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Information about a particular interface."
INDEX { ifIndex }
::= { flowInterfaceTable 1 }
FlowInterfaceEntry ::= SEQUENCE {
flowInterfaceSampleRate Integer32,
flowInterfaceLostPackets Counter32
}
flowInterfaceSampleRate OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The parameter N for statistical counting on this interface.
Set to N to count 1/Nth of the packets appearing at this
interface. A sampling rate of 1 counts all packets.
A sampling rate of 0 results in the interface being ignored
by the meter.
A meter should choose its own algorithm to introduce variance
into the sampling so that exactly every Nth packet is counted.
The IPPM Working Group's RFC'Framework for IP Performance
Metrics' [IPPM-FRM] explains why this should be done, and sets
out an algorithm for doing it."
DEFVAL { 1 }
::= { flowInterfaceEntry 1 }
flowInterfaceLostPackets OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of packets the meter has lost for this interface.
Such losses may occur because the meter has been unable to
keep up with the traffic volume."
::= { flowInterfaceEntry 2 }
--
-- Control Group: Meter Reader Info Table
--
-- Any meter reader wishing to collect data reliably for flows
-- should first create a row in this table. It should write that
-- row's flowReaderLastTime object each time it starts a collection
-- pass through the flow table.
-- If a meter reader (MR) does not create a row in this table, e.g.
-- because its MIB view [RFC2575] did not allow MR create access to
-- flowReaderStatus, collection can still proceed but the meter will
-- not be aware of meter reader MR. This could lead the meter to
-- recover flows before they have been collected by MR.
flowReaderInfoTable OBJECT-TYPE
SYNTAX SEQUENCE OF FlowReaderInfoEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An array of information about meter readers which have
registered their intent to collect flow data from this meter."
::= { flowControl 3 }
flowReaderInfoEntry OBJECT-TYPE
SYNTAX FlowReaderInfoEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Information about a particular meter reader."
INDEX { flowReaderIndex }
::= { flowReaderInfoTable 1 }
FlowReaderInfoEntry ::= SEQUENCE {
flowReaderIndex Integer32,
flowReaderTimeout Integer32,
flowReaderOwner UTF8OwnerString,
flowReaderLastTime TimeStamp,
flowReaderPreviousTime TimeStamp,
flowReaderStatus RowStatus,
flowReaderRuleSet Integer32
}
flowReaderIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index which selects an entry in the flowReaderInfoTable."
::= { flowReaderInfoEntry 1 }
flowReaderTimeout OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Specifies the maximum time (in seconds) between flow data
collections for this meter reader. If this time elapses
without a collection, the meter should assume that this meter
reader has stopped collecting, and delete this row from the
table. A value of zero indicates that this row should not be
timed out."
::= { flowReaderInfoEntry 2 }
flowReaderOwner OBJECT-TYPE
SYNTAX UTF8OwnerString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Identifies the meter reader which created this row."
::= { flowReaderInfoEntry 3 }
flowReaderLastTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Time this meter reader began its most recent data collection.
This variable should be written by a meter reader as its first
step in reading flow data. The meter will set this LastTime
value to its current Uptime, and set its PreviousTime value
(below) to the old LastTime. This allows the meter to
recover flows which have been inactive since PreviousTime,
for these have been collected at least once.
If the meter reader fails to write flowLastReadTime, collection
may still proceed but the meter may not be able to recover
inactive flows until the flowReaderTimeout has been reached
for this entry."
::= { flowReaderInfoEntry 4 }
flowReaderPreviousTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Time this meter reader began the collection before last."
::= { flowReaderInfoEntry 5 }
flowReaderStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this FlowReaderInfoEntry. A value of active(1)
implies that the associated reader should be collecting data
from the meter. Once this variable has been set to active(1)
a manager may only change this row's flowReaderLastTime and
flowReaderTimeout variables."
::= { flowReaderInfoEntry 6 }
flowReaderRuleSet OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An index to the array of RuleSets. Specifies a set of rules
of interest to this meter reader. The reader will attempt to
collect any data generated by the meter for this RuleSet, and
the meter will not recover the memory of any of the RuleSet's
flows until this collection has taken place. Note that a
reader may have entries in this table for several RuleSets."
::= { flowReaderInfoEntry 7 }
--
-- Control Group: Manager Info Table
--
-- Any manager wishing to run a RuleSet must create a row in this
-- table. Once it has a table row, the manager may set the control
-- variables in its row so as to cause the meter to run any valid
-- RuleSet held by the meter.
-- A single manager may run several RuleSets; it must create a row
-- in this table for each of them. In short, each row of this table
-- describes (and controls) a 'task' which the meter is executing.
flowManagerInfoTable OBJECT-TYPE
SYNTAX SEQUENCE OF FlowManagerInfoEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An array of information about managers which have
registered their intent to run RuleSets on this meter."
::= { flowControl 4 }
flowManagerInfoEntry OBJECT-TYPE
SYNTAX FlowManagerInfoEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Information about a particular meter 'task.' By creating
an entry in this table and activating it, a manager requests
that the meter 'run' the indicated RuleSet.
The entry also specifies a HighWaterMark and a StandbyRuleSet.
If the meter's flow table usage exceeds this task's
HighWaterMark the meter will stop running the task's
CurrentRuleSet and switch to its StandbyRuleSet.
If the value of the task's StandbyRuleSet is 0 when its
HighWaterMark is exceeded, the meter simply stops running the
task's CurrentRuleSet. By careful selection of HighWaterMarks
for the various tasks a manager can ensure that the most
critical RuleSets are the last to stop running as the number
of flows increases.
When a manager has determined that the demand for flow table
space has abated, it may cause the task to switch back to its
CurrentRuleSet by setting its flowManagerRunningStandby
variable to false(2)."
INDEX { flowManagerIndex }
::= { flowManagerInfoTable 1 }
FlowManagerInfoEntry ::= SEQUENCE {
flowManagerIndex Integer32,
flowManagerCurrentRuleSet Integer32,
flowManagerStandbyRuleSet Integer32,
flowManagerHighWaterMark Integer32,
flowManagerCounterWrap INTEGER,
flowManagerOwner UTF8OwnerString,
flowManagerTimeStamp TimeStamp,
flowManagerStatus RowStatus,
flowManagerRunningStandby TruthValue
}
flowManagerIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index which selects an entry in the flowManagerInfoTable."
::= { flowManagerInfoEntry 1 }
flowManagerCurrentRuleSet OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Index to the array of RuleSets. Specifies which set of
rules is the 'current' one for this task. The meter will
be 'running' the current RuleSet if this row's
flowManagerRunningStandby value is false(2).
When the manager sets this variable the meter will stop using
the task's old current RuleSet and start using the new one.
Specifying RuleSet 0 (the empty set) stops flow measurement
for this task."
::= { flowManagerInfoEntry 2 }
flowManagerStandbyRuleSet OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Index to the array of RuleSets. After reaching HighWaterMark
(see below) the manager will switch to using the task's
StandbyRuleSet in place of its CurrentRuleSet. For this to be
effective the designated StandbyRuleSet should have a coarser
reporting granularity then the CurrentRuleSet. The manager may
also need to decrease the meter reading interval so that the
meter can recover flows measured by this task's CurrentRuleSet."
DEFVAL { 0 } -- No standby
::= { flowManagerInfoEntry 3 }
flowManagerHighWaterMark OBJECT-TYPE
SYNTAX Integer32 (0..100)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"A value expressed as a percentage, interpreted by the meter
as an indication of how full the flow table should be before
it should switch to the standby RuleSet (if one has been
specified) for this task. Values of 0% or 100% disable the
checking represented by this variable."
::= { flowManagerInfoEntry 4 }
flowManagerCounterWrap OBJECT-TYPE
SYNTAX INTEGER { wrap(1), scale(2) }
MAX-ACCESS read-create
STATUS deprecated
DESCRIPTION
"Specifies whether PDU and octet counters should wrap when
they reach the top of their range (normal behaviour for
Counter64 objects), or whether their scale factors should
be used instead. The combination of counter and scale
factor allows counts to be returned as non-negative binary
floating point numbers, with 64-bit mantissas and 8-bit
exponents."
DEFVAL { wrap }
::= { flowManagerInfoEntry 5 }
flowManagerOwner OBJECT-TYPE
SYNTAX UTF8OwnerString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Identifies the manager which created this row."
::= { flowManagerInfoEntry 6 }
flowManagerTimeStamp OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Time this row was last changed by its manager."
::= { flowManagerInfoEntry 7 }
flowManagerStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this row in the flowManagerInfoTable. A value
of active(1) implies that this task may be activated, by
setting its CurrentRuleSet and StandbyRuleSet variables.
Its HighWaterMark and RunningStandby variables may also be
changed."
::= { flowManagerInfoEntry 8 }
flowManagerRunningStandby OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Set to true(1) by the meter to indicate that it has switched
to runnning this task's StandbyRuleSet in place of its
CurrentRuleSet. To switch back to the CurrentRuleSet, the
manager may simply set this variable to false(2)."
DEFVAL { false }
::= { flowManagerInfoEntry 9 }
--
-- Control Group: General Meter Control Variables
--
flowFloodMark OBJECT-TYPE
SYNTAX Integer32 (0..100)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"A value expressed as a percentage, interpreted by the meter
as an indication of how full the flow table should be before
it should take some action to avoid running out of resources
to handle new flows, as discussed in section 4.6 (Handling
Increasing Traffic Levels) of the RTFM Architecture RFC
[RTFM-ARC].
Values of 0% or 100% disable the checking represented by
this variable."
DEFVAL { 95 } -- Enabled by default.
::= { flowControl 5 }
flowInactivityTimeout OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The time in seconds since the last packet seen, after which
a flow becomes 'idle.' Note that although a flow may be
idle, it will not be discarded (and its memory recovered)
until after its data has been collected by all the meter
readers registered for its RuleSet."
DEFVAL { 600 } -- 10 minutes
::= { flowControl 6 }
flowActiveFlows OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of flows which are currently in use."
::= { flowControl 7 }
flowMaxFlows OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The maximum number of flows allowed in the meter's
flow table. At present this is determined when the meter
is first started up."
::= { flowControl 8 }
flowFloodMode OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Indicates that the meter has passed its FloodMark and is
not running in its normal mode.
When the manager notices this it should take action to remedy
the problem which caused the flooding. It should then monitor
flowActiveFlows so as to determine when the flood has receded.
At that point the manager may set flowFloodMode to false(2) to
resume normal operation."
::= { flowControl 9 }
--
-- The Flow Table
--
-- This is a table kept by a meter, with one flow data entry for every
-- flow being measured. Each flow data entry stores the attribute
-- values for a traffic flow. Details of flows and their attributes
-- are given in the 'Traffic Flow Measurement: Architecture'
-- document [RTFM-ARC].
-- From time to time a meter reader may sweep the flow table so as
-- to read counts. This is most effectively achieved by using the
-- TimeMark variable together with successive GetBulk requests to
-- retrieve the values of the desired flow attribute variables.
-- This scheme allows multiple meter readers to independently use the
-- same meter; the meter readers do not have to be synchronised and
-- they may use different collection intervals.
-- If identical sets of counts are required from a meter, a manager
-- could achieve this using two identical copies of a RuleSet in that
-- meter and switching back and forth between them. This is discussed
-- further in the RTFM Architecture document [RTFM-ARC].
flowDataTable OBJECT-TYPE
SYNTAX SEQUENCE OF FlowDataEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The list of all flows being measured."
::= { flowData 1 }
flowDataEntry OBJECT-TYPE
SYNTAX FlowDataEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The flow data record for a particular flow."
INDEX { flowDataRuleSet, flowDataTimeMark, flowDataIndex }
::= { flowDataTable 1 }
FlowDataEntry ::= SEQUENCE {
flowDataIndex Integer32,
flowDataTimeMark TimeFilter,
flowDataStatus INTEGER,
flowDataSourceInterface Integer32,
flowDataSourceAdjacentType AdjacentType,
flowDataSourceAdjacentAddress AdjacentAddress,
flowDataSourceAdjacentMask AdjacentAddress,
flowDataSourcePeerType PeerType,
flowDataSourcePeerAddress PeerAddress,
flowDataSourcePeerMask PeerAddress,
flowDataSourceTransType TransportType,
flowDataSourceTransAddress TransportAddress,
flowDataSourceTransMask TransportAddress,
flowDataDestInterface Integer32,
flowDataDestAdjacentType AdjacentType,
flowDataDestAdjacentAddress AdjacentAddress,
flowDataDestAdjacentMask AdjacentAddress,
flowDataDestPeerType PeerType,
flowDataDestPeerAddress PeerAddress,
flowDataDestPeerMask PeerAddress,
flowDataDestTransType TransportType,
flowDataDestTransAddress TransportAddress,
flowDataDestTransMask TransportAddress,
flowDataPDUScale Integer32,
flowDataOctetScale Integer32,
flowDataRuleSet Integer32,
flowDataToOctets Counter64, -- Source->Dest
flowDataToPDUs Counter64,
flowDataFromOctets Counter64, -- Dest->Source
flowDataFromPDUs Counter64,
flowDataFirstTime TimeStamp, -- Activity times
flowDataLastActiveTime TimeStamp,
flowDataSourceSubscriberID OCTET STRING,
flowDataDestSubscriberID OCTET STRING,
flowDataSessionID OCTET STRING,
flowDataSourceClass Integer32,
flowDataDestClass Integer32,
flowDataClass Integer32,
flowDataSourceKind Integer32,
flowDataDestKind Integer32,
flowDataKind Integer32
}
flowDataIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Value of this flow data record's index within the meter's
flow table."
::= { flowDataEntry 1 }
flowDataTimeMark OBJECT-TYPE
SYNTAX TimeFilter
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A TimeFilter for this entry. Allows GetNext and GetBulk
to find flow table rows which have changed since a specified
value of the meter's Uptime."
::= { flowDataEntry 2 }
flowDataStatus OBJECT-TYPE
SYNTAX INTEGER { inactive(1), current(2) }
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"Status of this flow data record."
::= { flowDataEntry 3 }
flowDataSourceInterface OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Index of the interface associated with the source address
for this flow. It's value is one of those contained in the
ifIndex field of the meter's interfaces table."
::= { flowDataEntry 4 }
flowDataSourceAdjacentType OBJECT-TYPE
SYNTAX AdjacentType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Adjacent address type of the source for this flow.
If metering is being performed at the network level,
AdjacentType will indicate the medium for the interface on
which the flow was observed and AdjacentAddress will be the
MAC address for that interface. This is the usual case.
If traffic is being metered inside a tunnel, AdjacentType will
be the peer type of the host at the end of the tunnel and
AdjacentAddress will be the peer address for that host."
::= { flowDataEntry 5 }
flowDataSourceAdjacentAddress OBJECT-TYPE
SYNTAX AdjacentAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Address of the adjacent device on the path for the source
for this flow."
::= { flowDataEntry 6 }
flowDataSourceAdjacentMask OBJECT-TYPE
SYNTAX AdjacentAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"1-bits in this mask indicate which bits must match when
comparing the adjacent source address for this flow."
::= { flowDataEntry 7 }
flowDataSourcePeerType OBJECT-TYPE
SYNTAX PeerType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Peer address type of the source for this flow."
::= { flowDataEntry 8 }
flowDataSourcePeerAddress OBJECT-TYPE
SYNTAX PeerAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Address of the peer device for the source of this flow."
::= { flowDataEntry 9 }
flowDataSourcePeerMask OBJECT-TYPE
SYNTAX PeerAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"1-bits in this mask indicate which bits must match when
comparing the source peer address for this flow."
::= { flowDataEntry 10 }
flowDataSourceTransType OBJECT-TYPE
SYNTAX TransportType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Transport address type of the source for this flow. The
value of this attribute will depend on the peer address type."
::= { flowDataEntry 11 }
flowDataSourceTransAddress OBJECT-TYPE
SYNTAX TransportAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Transport address for the source of this flow."
::= { flowDataEntry 12 }
flowDataSourceTransMask OBJECT-TYPE
SYNTAX TransportAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"1-bits in this mask indicate which bits must match when
comparing the transport source address for this flow."
::= { flowDataEntry 13 }
flowDataDestInterface OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Index of the interface associated with the dest address for
this flow. This value is one of the values contained in the
ifIndex field of the interfaces table."
::= { flowDataEntry 14 }
flowDataDestAdjacentType OBJECT-TYPE
SYNTAX AdjacentType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Adjacent address type of the destination for this flow."
::= { flowDataEntry 15 }
flowDataDestAdjacentAddress OBJECT-TYPE
SYNTAX AdjacentAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Address of the adjacent device on the path for the
destination for this flow."
::= { flowDataEntry 16 }
flowDataDestAdjacentMask OBJECT-TYPE
SYNTAX AdjacentAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"1-bits in this mask indicate which bits must match when
comparing the adjacent destination address for this flow."
::= { flowDataEntry 17 }
flowDataDestPeerType OBJECT-TYPE
SYNTAX PeerType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Peer address type of the destination for this flow."
::= { flowDataEntry 18 }
flowDataDestPeerAddress OBJECT-TYPE
SYNTAX PeerAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Address of the peer device for the destination of this flow."
::= { flowDataEntry 19 }
flowDataDestPeerMask OBJECT-TYPE
SYNTAX PeerAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"1-bits in this mask indicate which bits must match when
comparing the destination peer type for this flow."
::= { flowDataEntry 20 }
flowDataDestTransType OBJECT-TYPE
SYNTAX TransportType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Transport address type of the destination for this flow. The
value of this attribute will depend on the peer address type."
::= { flowDataEntry 21 }
flowDataDestTransAddress OBJECT-TYPE
SYNTAX TransportAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Transport address for the destination of this flow."
::= { flowDataEntry 22 }
flowDataDestTransMask OBJECT-TYPE
SYNTAX TransportAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"1-bits in this mask indicate which bits must match when
comparing the transport destination address for this flow."
::= { flowDataEntry 23 }
flowDataPDUScale OBJECT-TYPE
SYNTAX Integer32 (0..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The scale factor applied to this particular flow. Indicates
the number of bits the PDU counter values should be moved left
to obtain the actual values."
::= { flowDataEntry 24 }
flowDataOctetScale OBJECT-TYPE
SYNTAX Integer32 (0..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The scale factor applied to this particular flow. Indicates
the number of bits the octet counter values should be moved
left to obtain the actual values."
::= { flowDataEntry 25 }
flowDataRuleSet OBJECT-TYPE
SYNTAX Integer32 (1..255)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The RuleSet number of the RuleSet which created this flow.
Allows a manager to use GetNext or GetBulk requests to find
flows belonging to a particular RuleSet."
::= { flowDataEntry 26 }
flowDataToOctets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The count of octets flowing from source to destination
for this flow."
::= { flowDataEntry 27 }
flowDataToPDUs OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The count of packets flowing from source to destination
for this flow."
::= { flowDataEntry 28 }
flowDataFromOctets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The count of octets flowing from destination to source
for this flow."
::= { flowDataEntry 29 }
flowDataFromPDUs OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The count of packets flowing from destination to source
for this flow."
::= { flowDataEntry 30 }
flowDataFirstTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time at which this flow was first entered in the table"
::= { flowDataEntry 31 }
flowDataLastActiveTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The last time this flow had activity, i.e. the time of
arrival of the most recent PDU belonging to this flow."
::= { flowDataEntry 32 }
flowDataSourceSubscriberID OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (4..20))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Subscriber ID associated with the source address for this
flow. A Subscriber ID is an unspecified text string, used
to ascribe traffic flows to individual users. At this time
the means by which a Subscriber ID may be associated with a
flow is unspecified."
::= { flowDataEntry 33 }
flowDataDestSubscriberID OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (4..20))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Subscriber ID associated with the destination address for
this flow. A Subscriber ID is an unspecified text string,
used to ascribe traffic flows to individual users. At this
time the means by which a Subscriber ID may be associated
with a flow is unspecified."
::= { flowDataEntry 34 }
flowDataSessionID OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (4..10))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Session ID for this flow. Such an ID might be allocated
by a network access server to distinguish a series of sessions
between the same pair of addresses, which would otherwise
appear to be parts of the same accounting flow."
::= { flowDataEntry 35 }
flowDataSourceClass OBJECT-TYPE
SYNTAX Integer32 (1..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Source class for this flow. Determined by the rules, set by
a PushRule action when this flow was entered in the table."
::= { flowDataEntry 36 }
flowDataDestClass OBJECT-TYPE
SYNTAX Integer32 (1..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Destination class for this flow. Determined by the rules, set
by a PushRule action when this flow was entered in the table."
::= { flowDataEntry 37 }
flowDataClass OBJECT-TYPE
SYNTAX Integer32 (1..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Class for this flow. Determined by the rules, set by a
PushRule action when this flow was entered in the table."
::= { flowDataEntry 38 }
flowDataSourceKind OBJECT-TYPE
SYNTAX Integer32 (1..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Source kind for this flow. Determined by the rules, set by
a PushRule action when this flow was entered in the table."
::= { flowDataEntry 39 }
flowDataDestKind OBJECT-TYPE
SYNTAX Integer32 (1..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Destination kind for this flow. Determined by the rules, set
by a PushRule action when this flow was entered in the table."
::= { flowDataEntry 40 }
flowDataKind OBJECT-TYPE
SYNTAX Integer32 (1..255)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Class for this flow. Determined by the rules, set by a
PushRule action when this flow was entered in the table."
::= { flowDataEntry 41 }
--
-- The Activity Column Table
--
flowColumnActivityTable OBJECT-TYPE
SYNTAX SEQUENCE OF FlowColumnActivityEntry
MAX-ACCESS not-accessible
STATUS deprecated
DESCRIPTION
"Index into the Flow Table. Allows a meter reader to retrieve
a list containing the flow table indexes of flows which were
last active at or after a given time, together with the values
of a specified attribute for each such flow."
::= { flowData 2 }
flowColumnActivityEntry OBJECT-TYPE
SYNTAX FlowColumnActivityEntry
MAX-ACCESS not-accessible
STATUS deprecated
DESCRIPTION
"The Column Activity Entry for a particular attribute,
activity time and flow."
INDEX { flowColumnActivityAttribute, flowColumnActivityTime,
flowColumnActivityIndex }
::= { flowColumnActivityTable 1 }
FlowColumnActivityEntry ::= SEQUENCE {
flowColumnActivityAttribute FlowAttributeNumber,
flowColumnActivityTime TimeFilter,
flowColumnActivityIndex Integer32,
flowColumnActivityData OCTET STRING
}
flowColumnActivityAttribute OBJECT-TYPE
SYNTAX FlowAttributeNumber
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"Specifies the attribute for which values are required from
active flows."
::= { flowColumnActivityEntry 1 }
flowColumnActivityTime OBJECT-TYPE
SYNTAX TimeFilter
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"This variable is a copy of flowDataLastActiveTime in the
flow data record identified by the flowColumnActivityIndex
value of this flowColumnActivityTable entry."
::= { flowColumnActivityEntry 2 }
flowColumnActivityIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"Index of a flow table entry which was active at or after
a specified flowColumnActivityTime."
::= { flowColumnActivityEntry 3 }
flowColumnActivityData OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (3..1000))
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"Collection of attribute data for flows active after
flowColumnActivityTime. Within the OCTET STRING is a
sequence of { flow index, attribute value } pairs, one for
each active flow. The end of the sequence is marked by a
flow index value of 0, indicating that there are no more
rows in this column.
The format of objects inside flowColumnFlowData is as follows.
All numbers are unsigned. Numbers and strings appear with
their high-order bytes leading. Numbers are fixed size, as
specified by their SYNTAX in the flow table (above), i.e. one
octet for flowAddressType and small constants, and four octets
for Counter and TimeStamp. Strings are variable-length, with
the length given in a single leading octet.
The following is an attempt at an ASN.1 definition of
flowColumnActivityData:
flowColumnActivityData ::= SEQUENCE flowRowItemEntry
flowRowItemEntry ::= SEQUENCE {
flowRowNumber Integer32 (1..65535),
-- 0 indicates the end of this column
flowDataValue flowDataType -- Choice depends on attribute
}
flowDataType ::= CHOICE {
flowByteValue Integer32 (1..255),
flowShortValue Integer32 (1..65535),
flowLongValue Integer32,
flowStringValue OCTET STRING -- Length (n) in first byte,
-- n+1 bytes total length, trailing zeroes truncated
}"
::= { flowColumnActivityEntry 4 }
--
-- The Data Package Table
--
flowDataPackageTable OBJECT-TYPE
SYNTAX SEQUENCE OF FlowDataPackageEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Index into the Flow Table. Allows a meter reader to retrieve
a sequence containing the values of a specified set of
attributes for a flow which came from a specified RuleSet and
which was last active at or after a given time."
::= { flowData 3 }
flowDataPackageEntry OBJECT-TYPE
SYNTAX FlowDataPackageEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The data package containing selected variables from
active rows in the flow table."
INDEX { flowPackageSelector,
flowPackageRuleSet, flowPackageTime, flowPackageIndex }
::= { flowDataPackageTable 1 }
FlowDataPackageEntry ::= SEQUENCE {
flowPackageSelector OCTET STRING,
flowPackageRuleSet Integer32,
flowPackageTime TimeFilter,
flowPackageIndex Integer32,
flowPackageData OCTET STRING
}
flowPackageSelector OBJECT-TYPE
SYNTAX OCTET STRING
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Specifies the attributes for which values are required from
an active flow. These are encoded as a sequence of octets
each containing a FlowAttribute number, preceded by an octet
giving the length of the sequence (not including the length
octet). For a flowPackageSelector to be valid, it must
contain at least one attribute."
::= { flowDataPackageEntry 1 }
flowPackageRuleSet OBJECT-TYPE
SYNTAX Integer32 (1..255)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Specifies the index (in the flowRuleSetInfoTable) of the rule
set which produced the required flow."
::= { flowDataPackageEntry 2 }
flowPackageTime OBJECT-TYPE
SYNTAX TimeFilter
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This variable is a copy of flowDataLastActiveTime in the
flow data record identified by the flowPackageIndex
value of this flowPackageTable entry."
::= { flowDataPackageEntry 3 }
flowPackageIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Index of a flow table entry which was active at or after
a specified flowPackageTime."
::= { flowDataPackageEntry 4 }
flowPackageData OBJECT-TYPE
SYNTAX OCTET STRING
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A collection of attribute values for a single flow, as
specified by this row's indexes. The attribute values are
contained within a BER-encoded sequence [ASN-1, ASN-BER],
in the order they appear in their flowPackageSelector.
For example, to retrieve a flowPackage containing values for
attributes 11, 18 and 29, for a flow in RuleSet 7, with flow
index 3447, one would GET the package whose Object Identifier
(OID) is
flowPackageData . 3.11.18.29 . 7. 0 . 3447
To get a package for the next such flow which had been
active since time 12345 one would GETNEXT the package whose
Object Identifier (OID) is
flowPackageData . 3.11.18.29 . 7. 12345 . 3447"
::= { flowDataPackageEntry 5 }
--
-- The Rule Table
--
-- This is an array of RuleSets; the 'running' ones are indicated
-- by the entries in the meter's flowManagerInfoTable. Several
-- RuleSets can be held in a meter so that the manager can change the
-- running RuleSets easily, for example with time of day. Note that
-- a manager may not change the rules in any RuleSet currently
-- referenced within the flowManagerInfoTable (either as 'current' or
-- 'standby')! See the 'Traffic Flow Measurement: Architecture'
-- document [RTFM-ARC] for details of rules and how they are used.
-- Space for a RuleSet is allocated by setting the value of
-- flowRuleInfoSize in the rule table's flowRuleSetInfoTable row.
-- Values for each row in the RuleSet (Selector, Mask, MatchedValue,
-- Action and Parameter) can then be set by the meter.
-- Although an individual rule within a RuleSet could be modified,
-- it is much safer to simply download a complete new RuleSet.
flowRuleTable OBJECT-TYPE
SYNTAX SEQUENCE OF FlowRuleEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Contains all the RuleSets which may be used by the meter."
::= { flowRules 1 }
flowRuleEntry OBJECT-TYPE
SYNTAX FlowRuleEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The rule record itself."
INDEX { flowRuleSet, flowRuleIndex }
::= { flowRuleTable 1 }
FlowRuleEntry ::= SEQUENCE {
flowRuleSet Integer32,
flowRuleIndex Integer32,
flowRuleSelector RuleAttributeNumber,
flowRuleMask RuleAddress,
flowRuleMatchedValue RuleAddress,
flowRuleAction ActionNumber,
flowRuleParameter Integer32
}
flowRuleSet OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Selects a RuleSet from the array of RuleSets."
::= { flowRuleEntry 1 }
flowRuleIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The index into the Rule table. N.B: These values will
normally be consecutive, given the fall-through semantics
of processing the table."
::= { flowRuleEntry 2 }
flowRuleSelector OBJECT-TYPE
SYNTAX RuleAttributeNumber
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Indicates the attribute to be matched.
null(0) is a special case; null rules always succeed.
matchingStoD(50) is set by the meter's Packet Matching Engine.
Its value is true(1) if the PME is attempting to match the
packet with its addresses in Source-to-Destination order (i.e.
as they appear in the packet), and false(2) otherwise.
Details of how packets are matched are given in the 'Traffic
Flow Measurement: Architecture' document [RTFM-ARC].
v1(51), v2(52), v3(53), v4(54) and v5(55) select meter
variables, each of which can hold the name (i.e. selector
value) of an address attribute. When one of these is used
as a selector, its value specifies the attribute to be
tested. Variable values are set by an Assign action."
::= { flowRuleEntry 3 }
flowRuleMask OBJECT-TYPE
SYNTAX RuleAddress
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The initial mask used to compute the desired value. If the
mask is zero the rule's test will always succeed."
::= { flowRuleEntry 4 }
flowRuleMatchedValue OBJECT-TYPE
SYNTAX RuleAddress
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The resulting value to be matched for equality.
Specifically, if the attribute chosen by the flowRuleSelector
logically ANDed with the mask specified by the flowRuleMask
equals the value specified in the flowRuleMatchedValue, then
continue processing the table entry based on the action
specified by the flowRuleAction entry. Otherwise, proceed to
the next entry in the rule table."
::= { flowRuleEntry 5 }
flowRuleAction OBJECT-TYPE
SYNTAX ActionNumber
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The action to be taken if this rule's test succeeds, or if
the meter's 'test' flag is off. Actions are opcodes for the
meter's Packet Matching Engine; details are given in the
'Traffic Flow Measurement: Architecture' document [RTFM-ARC]."
::= { flowRuleEntry 6 }
flowRuleParameter OBJECT-TYPE
SYNTAX Integer32 (1..65535)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"A parameter value providing extra information for this rule's
action. Most of the actions use the parameter value to specify
which rule to execute after this rule's test has failed; details
are given in the 'Traffic Flow Measurement: Architecture'
document [RTFM-ARC]."
::= { flowRuleEntry 7 }
--
-- Traffic Flow Meter conformance statement
--
flowMIBCompliances
OBJECT IDENTIFIER ::= { flowMIBConformance 1 }
flowMIBGroups
OBJECT IDENTIFIER ::= { flowMIBConformance 2 }
flowControlGroup OBJECT-GROUP
OBJECTS {
flowRuleInfoSize, flowRuleInfoOwner,
flowRuleInfoTimeStamp, flowRuleInfoStatus,
flowRuleInfoName,
flowRuleInfoRulesReady,
flowRuleInfoFlowRecords,
flowInterfaceSampleRate,
flowInterfaceLostPackets,
flowReaderTimeout, flowReaderOwner,
flowReaderLastTime, flowReaderPreviousTime,
flowReaderStatus, flowReaderRuleSet,
flowManagerCurrentRuleSet, flowManagerStandbyRuleSet,
flowManagerHighWaterMark,
flowManagerCounterWrap,
flowManagerOwner, flowManagerTimeStamp,
flowManagerStatus, flowManagerRunningStandby,
flowFloodMark,
flowInactivityTimeout, flowActiveFlows,
flowMaxFlows, flowFloodMode }
STATUS deprecated
DESCRIPTION
"The control group defines objects which are used to control
an accounting meter."
::= {flowMIBGroups 1 }
flowDataTableGroup OBJECT-GROUP
OBJECTS {
-- flowDataIndex, <- INDEX, not-accessible
flowDataStatus,
flowDataSourceInterface,
flowDataSourceAdjacentType,
flowDataSourceAdjacentAddress, flowDataSourceAdjacentMask,
flowDataSourcePeerType,
flowDataSourcePeerAddress, flowDataSourcePeerMask,
flowDataSourceTransType,
flowDataSourceTransAddress, flowDataSourceTransMask,
flowDataDestInterface,
flowDataDestAdjacentType,
flowDataDestAdjacentAddress, flowDataDestAdjacentMask,
flowDataDestPeerType,
flowDataDestPeerAddress, flowDataDestPeerMask,
flowDataDestTransType,
flowDataDestTransAddress, flowDataDestTransMask,
-- flowDataRuleSet, <- INDEX, not-accessible
flowDataToOctets, flowDataToPDUs,
flowDataFromOctets, flowDataFromPDUs,
flowDataFirstTime, flowDataLastActiveTime,
flowDataSourceClass, flowDataDestClass, flowDataClass,
flowDataSourceKind, flowDataDestKind, flowDataKind
}
STATUS deprecated
DESCRIPTION
"The flow table group defines objects which provide the
structure for the flow table, including the creation time
and activity time indexes into it. In addition it defines
objects which provide a base set of flow attributes for the
adjacent, peer and transport layers, together with a flow's
counters and times. Finally it defines a flow's class and
kind attributes, which are set by rule actions."
::= {flowMIBGroups 2 }
flowDataScaleGroup OBJECT-GROUP
OBJECTS {
flowManagerCounterWrap,
flowDataPDUScale, flowDataOctetScale
}
STATUS deprecated
DESCRIPTION
"The flow scale group defines objects which specify scale
factors for counters."
::= {flowMIBGroups 3 }
flowDataSubscriberGroup OBJECT-GROUP
OBJECTS {
flowDataSourceSubscriberID, flowDataDestSubscriberID,
flowDataSessionID
}
STATUS current
DESCRIPTION
"The flow subscriber group defines objects which may be used
to identify the end point(s) of a flow."
::= {flowMIBGroups 4 }
flowDataColumnTableGroup OBJECT-GROUP
OBJECTS {
flowColumnActivityAttribute,
flowColumnActivityIndex,
flowColumnActivityTime,
flowColumnActivityData
}
STATUS deprecated
DESCRIPTION
"The flow column table group defines objects which can be used
to collect part of a column of attribute values from the flow
table."
::= {flowMIBGroups 5 }
flowDataPackageGroup OBJECT-GROUP
OBJECTS {
flowPackageData
}
STATUS current
DESCRIPTION
"The data package group defines objects which can be used
to collect a specified set of attribute values from a row of
the flow table."
::= {flowMIBGroups 6 }
flowRuleTableGroup OBJECT-GROUP
OBJECTS {
flowRuleSelector,
flowRuleMask, flowRuleMatchedValue,
flowRuleAction, flowRuleParameter
}
STATUS current
DESCRIPTION
"The rule table group defines objects which hold the set(s)
of rules specifying which traffic flows are to be accounted
for."
::= {flowMIBGroups 7 }
flowDataScaleGroup2 OBJECT-GROUP
OBJECTS {
-- flowManagerCounterWrap, <- Deprecated
flowDataPDUScale, flowDataOctetScale
}
STATUS current
DESCRIPTION
"The flow scale group defines objects which specify scale
factors for counters. This group replaces the earlier
version of flowDataScaleGroup above (now deprecated)."
::= {flowMIBGroups 8}
flowControlGroup2 OBJECT-GROUP
OBJECTS {
flowRuleInfoSize, flowRuleInfoOwner,
flowRuleInfoTimeStamp, flowRuleInfoStatus,
flowRuleInfoName,
-- flowRuleInfoRulesReady, <- Deprecated
flowRuleInfoFlowRecords,
flowInterfaceSampleRate,
flowInterfaceLostPackets,
flowReaderTimeout, flowReaderOwner,
flowReaderLastTime, flowReaderPreviousTime,
flowReaderStatus, flowReaderRuleSet,
flowManagerCurrentRuleSet, flowManagerStandbyRuleSet,
flowManagerHighWaterMark,
-- flowManagerCounterWrap, <- Moved to DataScaleGroup
flowManagerOwner, flowManagerTimeStamp,
flowManagerStatus, flowManagerRunningStandby,
flowFloodMark,
flowInactivityTimeout, flowActiveFlows,
flowMaxFlows, flowFloodMode }
STATUS current
DESCRIPTION
"The control group defines objects which are used to control
an accounting meter. It replaces the earlier version of
flowControlGroup above (now deprecated)."
::= {flowMIBGroups 9 }
flowMIBCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for a Traffic Flow Meter."
MODULE
MANDATORY-GROUPS {
flowControlGroup2,
flowDataTableGroup,
flowDataPackageGroup,
flowRuleTableGroup
}
::= { flowMIBCompliances 1 }
END
5 Security Considerations
5.1 SNMP Concerns
There are a number of management objects defined in this MIB that
have a MAX-ACCESS clause of read-write and/or read-create. Such
objects may be considered sensitive or vulnerable in some network
environments. The support for SET operations in a non-secure
environment without proper protection can have a negative effect on
network operations.
There are a number of managed objects in this MIB that may contain
sensitive information. These include all the objects in the Control
Group (since they control access to meter resources by Managers and
Meter Readers) and those in the Flow Table (since they hold the
collected traffic flow data).
It is thus important to control even GET access to these objects and
possibly to even encrypt the values of these object when sending them
over the network via SNMP. Not all versions of SNMP provide features
for such a secure environment.
SNMPv1 by itself is not a secure environment. Even if the network
itself is secure (for example by using IPSec), even then, there is no
control as to who on the secure network is allowed to access and
GET/SET (read/change/create/delete) the objects in this MIB.
It is recommended that the implementers consider the security
features as provided by the SNMPv3 framework. Specifically, the use
of the User-based Security Model [RFC2574] and the View-based Access
Control Model [RFC2575] is recommended.
It is then a customer/user responsibility to ensure that the SNMP
entity giving access to an instance of this MIB is properly
configured to give access to the objects only to those principals
(users) that have legitimate rights to indeed GET or SET
(change/create/delete) them.
5.2 Traffic Meter Concerns
This MIB describes how an RTFM traffic meter is controlled, and
provides a way for traffic flow data to be retrieved from it by a
meter reader. This is essentially an application using SNMP as a
method of communication between co-operating hosts; it does not - in
itself - have any inherent security risks.
Since, however, the traffic flow data can be extremely valuable for
network management purposes it is vital that sensible precautions be
taken to keep the meter and its data secure. In particular, an
attacker must not be permitted to write any of the meter's variables!
This requires that access to the meter for control purposes (e.g.
loading RuleSets and reading flow data) be restricted. Such
restriction could be achieved in many ways, for example:
- Physical Separation. Meter(s) and meter reader(s) could be
deployed so that control capabilities are kept within a separate
network, access to which is carefully controlled.
- Application-layer Security. A minimal level of security for SNMP
can be provided by using 'community' strings (which are essentially
clear-text passWords) with SNMPv2C [RFC1157]. Where stronger
security is needed, users should consider using the User-based
Security Model [RFC2574] and the View-based Access Control Model
[RFC2575].
- Lower-layer Security. Access to the meter can be protected using
encryption at the network layer. For example, one could run SNMP
to the meter through an encrypted TCP tunnel.
When implementing a meter it may be sensible to use separate network
interfaces for control and for metering. If this is done the control
network can be set up so that it doesn't carry any 'user' traffic,
and the metering interfaces can ignore any user attempts to take
control of the meter.
Users should also consider how they will address attempts to
circumvent a meter, i.e. to prevent it from measuring flows. Such
attempts are essentially denial-of-service attacks on the metering
interfaces. For example
- Port Scan attacks. The attacker sends packets to each of a very
large number of IP (Address : Port) pairs. Each of these packets
creates a new flow in the meter; if there are enough of them the
meter will recognise a 'flood' condition, and will probably stop
creating new flows. As a minimum, users (and implementors) should
ensure that meters can recover from flood conditions as soon as
possible after they occur.
- Counter Wrap attacks: The attacker sends enough packets to cause
the counters in a flow to wrap several times between meter
readings, thus causing the counts to be artificially low. The
change to using 64-bit counters in this MIB reduces this problem
significantly.
Users can reduce the severity of both the above attacks by ensuring
that their meters are read often enough to prevent them being
flooded. The resulting flow data will contain a record of the
attacking packets, which may well be useful in determining where any
attack came from.
6 IANA Considerations
The RTFM Architecture document [RTFM-ARC], has two sets of assigned
numbers: Opcodes for the PME (Pattern Matching Engine) and RTFM
Attribute numbers. All the assigned numbers used in the Meter MIB
appear in Textual Conventions. The numbers they use are derived as
follows:
The MIB's 'Type' textual conventions use names and numbers from the
Assigned Numbers RFC[ASG-NBR]:
MediumType Uses ifType Definitions
PeerType Uses Address Family Numbers
TransportType Uses Protocol Numbers
The MIB's 'AttributeNumber' textual conventions use RTFM Attribute
names and numbers from the RTFM Architecture document [RTFM-ARC], or
other numbers allocated according to that document's IANA
Considerations section:
FlowAttributeNumber Have values stored in a flow table row
RuleAttributeNumber May be tested in a rule
The MIB's ActionNumber textual convention uses RTFM PME Opcode names
and numbers from the RTFM Architecture document [RTFM-ARC], or other
numbers allocated according to that document's IANA Considerations
section.
7 Appendix A: Changes Introduced Since RFC2064
The first version of the Meter MIB was published as RFC2064 in
January 1997. The most significant changes since then are summarised
below.
- TEXTUAL CONVENTIONS: Greater use is made of textual conventions to
describe the various types of addresses used by the meter.
- PACKET MATCHING ATTRIBUTES: Computed attributes (e.g. FlowClass and
FlowKind) may now be tested. This allows one to use these
variables to store information during packet matching.
A new attribute, MatchingStoD, has been added. Its value is 1
while a packet is being matched with its adresses in 'wire'
(source-to-destination) order.
- FLOOD MODE: This is now a read-write variable. Setting it to
false(2) switches the meter out of flood mode and back to normal
operation.
- CONTROL TABLES: Several variables have been added to the RuleSet,
Reader and Manager tables to provide more effective control of the
meter's activities.
- FLOW TABLE: 64-bit counters are used for octet and PDU counts.
This reduces the problems caused by the wrap-around of 32-bit
counters in earlier versions.
flowDataRuleSet is now used as an index to the flow table. This
allows a meter reader to collect only those flow table rows created
by a specified RuleSet.
- DATA PACKAGES: This is a new table, allowing a meter reader to
retrieve values for a list of attributes from a flow as a single
object (a BER-encoded sequence [ASN-1, ASN-BER]). It provides an
efficient way to recover flow data, particularly when used with
SNMP GetBulk requests.
Earlier versions had a 'Column Activity Table'; using this it was
difficult to collect all data for a flow efficiently in a single
SNMP request.
8 Acknowledgements
An early draft of this document was produced under the auspices of
the IETF's Accounting Working Group with assistance from the SNMP
Working Group and the Security Area Advisory Group. Particular
thanks are due to Jim Barnes, Sig Handelman and Stephen Stibler for
their support and their assistance with checking early versions of
the MIB.
Stephen Stibler shared the development workload of producing the MIB
changes summarized in chapter 5 (above).
9 Intellectual Property Notice
The IETF takes no position regarding 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 the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such
proprietary rights by implementers 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 address the information to the IETF Executive
Director.
10 References
[ACT-BKG] Mills, C., Hirsch, G. and G. Ruth, "Internet Accounting
Background", RFC1272, November 1991.
[ASG-NBR] Reynolds, J. and J. Postel, "Assigned Numbers", STD 2,
RFC1700, ISI, October 1994.
[ASN-1] Information processing systems - Open Systems
Interconnection - Specification of Abstract Syntax
Notation One (ASN.1), International Organization for
Standardization, International Standard 8824, December
1987.
[ASN-BER] 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.
[ENET-OBJ] Kastenholz, F., "Definitions of Managed Objects for the
Ethernet-like Interface Types", RFC1643, July 1994.
[FDDI-MIB] Case, J. and A. Rijsinghani, "FDDI Management Information
Base", RFC1512, September 1993.
[IPPM-FRM] Paxson, V., Almes, G., Mahdavi, J. and M. Mathis,
"Framework for IP Performance Metrics", RFC2330, May
1998.
[MIB-II] McCloghrie, K. and M. Rose, "Management Information Base
for Network Management of TCP/IP-based internets: MIB-
II", STD 17, RFC1213, March 1991.
[RFC1155] Rose, M., and K. McCloghrie, "Structure and
Identification of Management Information for TCP/IP-based
Internets", STD 16, RFC1155, May 1990
[RFC1157] Case, J., Fedor, M., Schoffstall, M. and J. Davin,
"Simple Network Management Protocol", STD 15, RFC1157,
May 1990.
[RFC1212] Rose, M. and K. McCloghrie, "Concise MIB Definitions",
STD 16, RFC1212, March 1991.
[RFC1215] Rose, M., "A Convention for Defining Traps for use with
the SNMP", RFC1215, March 1991
[RFC1901] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Introduction to Community-based SNMPv2", RFC1901,
January 1996.
[RFC1905] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Protocol Operations for Version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC1905, January 1996.
[RFC1906] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Transport Mappings for Version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC1906, January 1996.
[RFC1908] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Coexistence between version 1 and version 2 of the
Internet-standard Network Management Framework", RFC
1908, January 1996.
[RFC2570] Case, J., Mundy, R., Partain, D. and B. Stewart,
"Introduction to Version 3 of the Internet-standard
Network Management Framework", RFC2570, April 1999.
[RFC2571] Harrington, D., Presuhn, R. and B. Wijnen, "An
Architecture for Describing SNMP Management Frameworks",
RFC2571, April 1999.
[RFC2572] Case, J., Harrington D., Presuhn R. and B. Wijnen,
"Message Processing and Dispatching for the Simple
Network Management Protocol (SNMP)", RFC2572, April
1999.
[RFC2573] Levi, D., Meyer, P. and B. Stewart, "SNMPv3
Applications", RFC2573, April 1999.
[RFC2574] Blumenthal, U. and B. Wijnen, "User-based Security Model
(USM) for version 3 of the Simple Network Management
Protocol (SNMPv3)", RFC2574, April 1999.
[RFC2575] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based
Access Control Model (VACM) for the Simple Network
Management Protocol (SNMP)", RFC2575, April 1999.
[RFC2578] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M. and S. Waldbusser, "Structure of Management
Information Version 2 (SMIv2)", STD 58, RFC2578, April
1999.
[RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M. and S. Waldbusser, "Textual Conventions for
SMIv2", STD 58, RFC2579, April 1999.
[RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M. and S. Waldbusser, "Conformance Statements for
SMIv2", STD 58, RFC2580, April 1999.
[RMON-MIB] Waldbusser, S., "Remote Network Monitoring Management
Information Base", RFC1757, February 1995.
[RMON2-MIB] Waldbusser, S., "Remote Network Monitoring Management
Information Base Version 2 using SMIv2", RFC2021,
January 1997.
[RTFM-ARC] Brownlee, N., Mills, C. and Ruth, G., "Traffic Flow
Measurement: Architecture", RFC722, October 1999.
[UTF-8] Yergeau, F., "UTF-8, a transformation format of ISO
10646", RFC2279, January 1998.
[V6-ADDR] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC2373, July 1998.
11 Author's Address
Nevil Brownlee
Information Technology Systems & Services
The University of Auckland
Private Bag 92-019
Auckland, New Zealand
Phone: +64 9 373 7599 x8941
EMail: n.brownlee@auckland.ac.nz
12 Full Copyright Statement
Copyright (C) The Internet Society (1999). 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 RFCEditor function is currently provided by the
Internet Society.
