Network Working Group F. Strauss
Internet-Draft J. Schoenwaelder
Expires: January 18, 2002 TU Braunschweig
July 20, 2001
SMIng Internet Protocol Core Modules
draft-ietf-sming-inet-modules-02
Status of this Memo
This document is an Internet-Draft and is in full conformance with
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Copyright Notice
Copyright (C) The Internet Society (2001). All Rights Reserved.
Abstract
This memo presents SMIng modules that introduce commonly used
Internet Protocol specific data definitions. They are provided so
that other SMIng modules that would otherwise define their own
representations can import them from a common place.
The IETF-INET module defines types and classes for representing
Internet Protocol specific information. It builds on RFC 2851 and
extends it in several ways.
The IETF-INET-FILTER module extends the IETF-INET module by providing
generic definitions for typical IP packet filters.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. IETF-INET . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. IETF-INET-FILTER . . . . . . . . . . . . . . . . . . . . . . . 9
4. Usage Examples . . . . . . . . . . . . . . . . . . . . . . . . 11
5. Security Considerations . . . . . . . . . . . . . . . . . . . 13
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13
References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 13
A. OPEN ISSUES . . . . . . . . . . . . . . . . . . . . . . . . . 14
Full Copyright Statement . . . . . . . . . . . . . . . . . . . 15
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1. Introduction
SMIng [1] modules frequently need to represent Internet Protocol
specific information such as IP addresses. This memo contains SMIng
modules which define a core set of SMIng types and classes to be
imported by other SMIng modules.
The IETF-INET module provides core SMIng data definitions for the
Internet Protocol suite. This module is derived from [3].
The IETF-INET-FILTER module provides SMIng data definitions that
model Internet Protocol filters and components thereof.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [2].
2. IETF-INET
module IETF-INET {
organization "IETF Next Generation Structure of
Management Information Working Group (SMING)";
contact "Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Phone: +49 531 391-3289
EMail: schoenw@ibr.cs.tu-bs.de";
description "This module defines core types and classes for
the Internet Protocol suite. This document builds
upon RFC 2851 and extends it in various ways.";
revision {
date "2001-03-02";
description "Initial revision, published as RFC &rfc.number;.";
};
//
// Core type definitions for the Internet Protocol suite.
//
typedef InetPortNumber {
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type Unsigned32 (0..65535);
description
"Represents a 16 bit port number of an Internet
transport layer protocol. Port numbers are assigned by
IANA. A list of all assignments is available from
<http://www.iana.org/>.
The value zero is object-specific and must be defined as
part of the description of any object which uses this
syntax. Examples of the usage of zero might include
situations where a port number is unknown, or when the
value zero is used as a wildcard in a filter.";
reference
"STD 6 (RFC 768), STD 7 (RFC 793) and RFC 2960";
};
typedef InetProtocolNumber {
type Unsigned32 (0..255);
description
"Represents an 8 bit protocol number which indicates the
next upper-layer protocol used in the data portion of an
Internet datagram. Protocol numbers are assigned by
IANA. A list of all assignments is available at the
from <http://www.iana.org/>".;
reference
"STD 5 (RFC 791) Section 3.1 and RFC 2460 Section 3.";
};
typedef InetDiffServCodePoint {
type Unsigned32 (-1, 0..63);
description
"Represents a 6 bit Differentiated Services Code Point
(DSCP). The special value -1 may be used to indicate
e.g. a wildnot in a filter.";
reference
"RFC 2474";
};
typedef InetAddress {
type OctetString;
description
"Represents a generic IP version neutral Internet address.";
};
typedef InetAddressPrefixLength {
type Unsigned32;
description
"Denotes the length of a generic Internet network address
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prefix. A value of n corresponds to an IP address mask
which has n contiguous 1-bits from the most significant
bit (MSB) and all other bits set to 0.
InetAddressPrefixLength values that are larger than
the maximum length of an IP address for a specific
InetAddressType are treated as the maximum significant
value applicable for the InetAddressType. The maximum
significant value is 32 for the InetAddressType
'ipv4(1)' and 128 for the InetAddressType 'ipv6(2)'.
The maximum significant value for the InetAddressType
'dns(16)' is 0.
The value zero is object-specific and must be defined as
part of the description of any object which uses this
syntax. Examples of the usage of zero might include
situations where the Internet network address prefix
is unknown or does not apply.";
};
typedef InetAutonomousSystemNumber {
type Unsigned32;
description
"Represents an autonomous system number which identifies an
Autonomous System (AS). An AS is a set of routers under a
single technical administration, using an interior gateway
protocol and common metrics to route packets within the AS,
and using an exterior gateway protocol to route packets to
other ASs'. IANA maintains the AS number space and has
delegated large parts to the regional registries.
Autonomous system numbers are currently limited to 16 bits
(0..65535). There is however work in progress to enlarge the
autonomous system number space to 32 bits. This textual
convention therefore uses an Unsigned32 value without a
range restriction in order to support a larger autonomous
system number space.";
reference
"RFC 1771, RFC 1930";
};
//
// Internet Protocol address types for specific IP versions.
//
typedef InetAddressType {
type Enumeration (unknown(0), ipv4(1), ipv6(2),
dns(16));
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description
"A value that represents a type of Internet address.
unknown(0) An unknown address type. This value MUST
be used if the value of the corresponding
address attribute is a zero-length string.
It may also be used to indicate an IP address
which is not in one of the formats defined
below.
ipv4(1) An IPv4 address as defined by the
InetAddressIPv4 type.
ipv6(2) An IPv6 address as defined by the
InetAddressIPv6 type.
dns(16) A DNS domain name as defined by the
InetAddressDNS type.
The type SHOULD NOT be subtyped to support future
extensions. It MAY be subtyped in compliance statements
in order to require only a subset of these address types
for a compliant implementation.";
};
typedef InetAddressIPv4 {
type InetAddress (4);
format "1d.1d.1d.1d";
description
"Represents a 32 bit IP version 4 (IPv4) network address:
octets contents encoding
1-4 IPv4 address network-byte order
If there is a corresponding InetAddressType attribute,
its value MUST be ipv4(1).";
reference
"STD 5 (RFC 791)";
};
typedef InetAddressIPv6 {
type InetAddress (16 | 20);
format "2x:2x:2x:2x:2x:2x:2x:2x%4d";
description
"Represents a 128 bit IPv6 network address plus an
optional 32 bit scope identifier:
octets contents encoding
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1-16 IPv6 address network-byte order
17-20 scope identifier network-byte order
If there is a corresponding InetAddressType attribute,
its value MUST be ipv6(2).
The scope identifier (bytes 17-20) MUST NOT be present
for global IPv6 addresses. For non-global IPv6 addresses
(e.g. link-local or site-local addresses), the scope
identifier MUST always be present. It contains a link
identifier for link-local and a site identifier for
site-local IPv6 addresses.
The scope identifier MUST disambiguate identical address
values. For link-local addresses, the scope identifier will
typically be the interface index (ifIndex as defined in the
IF-MIB, RFC 2233) of the interface on which the address is
configured.
The scope identifier may contain the special value 0
which refers to the default scope. The default scope
may be used in cases where the valid scope identifier
is not known (e.g., a management application needs to
write a site-local InetAddressIPv6 address without
knowing the site identifier value). The default scope
SHOULD NOT be used as an easy way out in cases where
the scope identifier for a non-global IPv6 address is
known.";
reference
"RFC 2373";
};
typedef InetAddressDNS {
type InetAddress (1..255);
format "255a";
description
"Represents a DNS domain name. The name SHOULD be
fully qualified whenever possible.
If there is a corresponding InetAddressType attribute,
its value MUST be dns(16).
The descriptions of attributes of this type must fully
describe how (and when) such names are to be resolved
to IP addresses.";
};
//
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// Core class definitions for the Internet Protocol suite.
//
class InetNetworkEndpoint {
attribute InetAddressType type {
access readwrite;
description
"The type of this Internet Protocol endpoint.";
};
attribute InetAddress address {
typemap type {
map ipv4 InetAddressIPv4;
map ipv6 InetAddressIPv6;
map dns InetAddressDNS;
};
access readwrite;
description
"The address of this Internet Protocol endpoint.
An address value is always interpreted within the
context of the type value. The type attribute defines
the context.";
};
description
"This class defines a generic Internet Protocol endpoint
at the network layer.";
};
class InetTransportEndpoint {
attribute InetNetworkEndpoint address {
description
"The network layer endpoint.";
};
attribute InetPortNumber port {
description
"The transport layer port number.";
};
description
"This class defines a generic transport layer endpoint for
the Internet Protocol suite.";
};
class InetSubnet {
attribute InetNetworkEndpoint endpoint {
description
"A network layer endpoint within the Internet
Protocol subnet.";
}
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attribute InetAddressPrefixLength prefix {
description
"The address prefix which identifies the subnet
portion of the address of the network layer
endpoint.";
};
description
"This class defines a generic Internet Protocol subnet.";
};
class InetPortNumberRange {
attribute InetPortNumber start {
access readwrite;
description
"The first port number in the port range.";
};
attribute InetPortNumber end {
access readwrite;
description
"The last port number in the port range.";
};
description
"This class represents a range of consecutive Internet
transport layer port numbers. The start and end port
numbers are included in the range of consecutive port
numbers.";
};
};
3. IETF-INET-FILTER
module IETF-INET-FILTER {
import IETF-INET (InetProtocolNumber,
InetDiffServCodePoint,
InetPortNumberRange,
InetSubnet);
import IETF-SMING (Counter64,
DisplayString255);
organization "IETF Next Generation Structure of
Management Information Working Group (SMING)";
contact "Juergen Schoenwaelder
TU Braunschweig
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Bueltenweg 74/75
38106 Braunschweig
Germany
Phone: +49 531 391-3289
EMail: schoenw@ibr.cs.tu-bs.de";
description "This module defines core filter classes for
the Internet protocol suite.";
revision {
date "2001-03-02";
description "Initial revision, published as RFC &rfc.number;.";
};
class Filter {
attribute DisplayString255 name {
access readwrite;
description
"The administratively assigned name of the filter.";
};
attribute Counter64 packets {
access readonly;
units "packets";
"The number of packets matching this filter.";
};
attribute Counter64 bytes {
access readonly;
units "bytes";
description
"The number of bytes contained in packets matching
this filter.";
};
description
"A generic filter. Classes derived from this generic filter
must introduce additional attributes which define the
filter parameters.";
};
class InetFilter : Filter {
attribute InetSubnet srcSubNet {
description
"The subnet to match against the packet's
source address.";
};
attribute InetSubnet dstSubNet {
description
"The subnet to match against the packet's
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destination address.";
};
attribute InetPortRange srcPortRange {
description
"The port range to match against the packet's
source port."
};
attribute InetPortRange dstPortRange {
description
"The port range to match against the packet's
destination port.";
};
attribute InetProtocolNumber protocol {
access readwrite;
description
"The protocol number to match against the packet's
Internet Protocol version. A value of zero
matches any IP version.";
};
attribute InetDiffServCodePoint dscp {
access readwrite;
description
"The value that the DSCP in the packet must have to
match this entry. A value of -1 indicates that a
specific DSCP value has not been defined and thus all
DSCP values are considered a match.";
}
description
"This class represents a generic Internet Protocol filter.
Classes derived from this class may add attributes which
define further filter criteria.";
};
};
4. Usage Examples
The following example shows how a TCP connection might be modelled.
The class definition below could be used to derive an IP version
independent MIB for representing open TCP connections.
module IETF-TCP {
import IETF-INET (InetTransportEndpoint);
// ...
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typedef TcpConnectionState {
type Enumeration (closed(1), listen(2), synSent(3),
synReceived(4), established(5),
finWait1(6), finWait2(7), closeWait(8),
lastAck(9), closing(10), timeWait(11));
description
"The state of a TCP connection.";
reference
"STD 7 (RFC 793)";
};
typedef TcpConnectionCtrl {
type Enumeration (none(0), delete(1));
description
"The enumerated numbers defined by this type allow to control
TCP connections. The value none(0) will be reported whenever
an attribute of this type is read.
The only value which may be written is delete(1). If a
management station writes the value delete(1), then this
has the effect of deleting the TCB (as defined in RFC 793)
of the corresponding connection on the managed node,
resulting in immediate termination of the connection.
As an implementation-specific option, a RST segment may be
sent from the managed node to the other TCP endpoint (note
however that RST segments are not sent reliably).";
};
class TcpConnection {
attribute InetTransportEndpoint local {
description
"The local endpoint of the TCP connection.";
};
attribute InetTransportEndpoint remote {
description
"The remote endpoint of the TCP connection.";
};
attribute TcpConnectionState state {
access readonly;
description
"The current state of the TCP connection.";
};
attribute TcpConnectionCtrl ctrl {
access readwrite;
description
"A control which allows to change the state of the
TCP connection.";
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};
description
"This class contains information about a particular current
TCP connection.";
};
};
5. Security Considerations
This module does not define any management objects. Instead, it
defines a set of SMIng types and classes which may be used by other
SMIng modules to define management objects. These data definitions
have no security impact on the Internet.
6. Acknowledgments
Some definitions in this document are derived from RFC 2851 [3],
which was written by M. Daniele, B. Haberman, S. Routhier and J.
Schoenwaelder.
References
[1] Strauss, F. and J. Schoenwaelder, "SMIng - Next Generation
Structure of Management Information", draft-ietf-sming-02.txt,
July 2001.
[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", RFC 2119, BCP 14, March 1997.
[3] Daniele, M., Haberman, B., Routhier, S. and J. Schoenwaelder,
"Textual Conventions for Internet Network Addresses", RFC 2851,
June 2000.
Authors' Addresses
Frank Strauss
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Phone: +49 531 391-3266
EMail: strauss@ibr.cs.tu-bs.de
URI: http://www.ibr.cs.tu-bs.de/
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Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Phone: +49 531 391-3289
EMail: schoenw@ibr.cs.tu-bs.de
URI: http://www.ibr.cs.tu-bs.de/
Appendix A. OPEN ISSUES
What else is missing? - There might be more core type or class
definitions that should go into the IETF-SMING-INET module.
Are the filters sufficiently flexible? - The filters probably need
more work to cover more cases. Should the IETF-INET-FILTER module
become a separate document?
More examples needed? - Is it useful to include more examples, e.g.
on the usage of filters or subnets?
Dscp Definition - Does the InetDiffServCodePoint type definition
really belong into this module?
InetAddressDNS Format - 255a or 255t? Length restriction?
Usage of the terms Endpoint and Address - Check the attribute
identifiers and descriptions of InetTransportEndpoint and
InetSubnet: when should the term endpoint be used, and when
address?
InetProtocolNumber and InetTransportEndpoint - Should an
InetProtocolNumber attribute be added to the
InetTransportEndpoint?
Undocumented typemap keyword - This feature needs more work. We
either define such a type casting mechanism or we add a real
discriminated union to the SMIng type system.
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Full Copyright Statement
Copyright (C) The Internet Society (2001). All Rights Reserved.
This document and translations of it may be copied and furnished to
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or assist in its implementation may be prepared, copied, published
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Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
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