Network management
Ohud92
Ch4--myslides.ppt
Chapter 4
SNMPv1 Network Management:
Organization and Information Models
Chapter 4 SNMPv1 Network Management: Organization and Information Models
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Network Management: Principles and Practice
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Objectives
- IETF SNMP standard
History
RFC, STD, and FYI
- Organization Model
2- and 3-tier models
Manager and agent
- Management messages
- Structure of management information, SMI
- Object type and instance
- Scalar and aggregate managed objects
- Management information base, MIB
- NMS physical and virtual databases
- IETF MIB-2 standard
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- AT&T Network Management Centers
- Network Control Centers
- Network Operations Center
- CNN World Headquarters
- Centralized troubleshooting of NIC
- Performance degradation due to NMS
- Bell Operating company procedure
Case Histories
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Several visits show how big corporations and institutions manage their big networks
- Automated network monitoring with network and status shown on large screen
- Automated Recovery from failure for a wide range of failures
- alarms for unrecoverable failures
- remote tests for network parts
- ………
A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter, and by similar terms
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Managed LAN: example
- NMS on subnet 192.168.252.1 manages the router and the hubs on subnet 172.16.46.1 across the backbone network
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
The NMS, whose IP address is 192.168.252.110, is physically and logically located remotely from the 172.16.46.1 LAN. It is configured on the LAN 192.168.252.1 and is connected to the backbone network.
A backbone is a larger transmission line that carries data gathered from smaller lines that interconnect with it.
A backbone is a larger transmission line that carries data gathered from smaller lines that interconnect with it.
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- Information obtained by querying the hub
- Data truly reflects what is stored in the hub
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Title: System Information: 172.16.46.2
Name or IP Address: 172.16.46.2
System Name:
System Description: 3Com LinkBuilder FMS, SW version:3.02
System Contact:
System Location:
System Object ID: iso.org.dod.internet.private.enterprises.43.1.8.5
System Up Time: (2475380437) 286 days, 12:03:24.37
Figure 4.2(a) System Information on 172.16.46.2 Hub
Managed Router (router 2):
System Information
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Title: System Information: router1.gatech.edu
Name or IP Address: 172.16.252.1
System Name : router1.gatech.edu
System Description : Cisco Internetwork Operating System Software
: IOS (tm) 7000 Software (C7000-JS-M), Version : 11.2(6),RELEASE SOFTWARE (ge1)
: Copyright (c) 1986-1997 by Cisco Systems, Inc.
: Compiled Tue 06-May-97 19:11 by kuong
System Contact
System Location :
System Object ID : iso.org.dod.internet.private.enterprises.cisco.ciscoProducts.
cisco 7000
System Up Time : (315131795) 36 days, 11:21:57.95
Figure 4.2(c) System Information on Router
- Information acquired by the NMS on hub interfaces
- Index refers to the interface on the hub
- Link address is the MAC address
- The second row data is a serial link (serial port hub)
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Index
Interface
IP address
Network Mask
Network Address
Link Address
1
3Com
172.16.46.2
255.255.255.0
172.16 46.0
0x08004E07C25C
2
3Com
192.168.101.1
255.255.255.0
192.168.101.0
<none>
it is often referred to as hardware or physical address. MAC addresses are 6-byte (48-bits) in length, and are written in MM:MM:MM:SS:SS:SS format. The first 3-bytes are ID number of the manufacturer, which is assigned by an Internet standards body. The second 3-bytes are serial number assigned by the manufacturer.
MAC layer represents layer 2 of the TCP/IP (adopted from OSI Reference Model), where IP represents layer 3. MAC address can be thought of as supporting hardware implementation whereas IP address supports software implementation. MAC addresses are permanently burned into hardware by hardware manufacturer, but IP addresses are assigned to the network devices by a network administrator. DHCP relies on MAC address to assign IP addresses to network devices.
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- Information acquired by NMS on the router interfaces
- Index refers to the interface on the router
- LEC is the LAN emulation card (for interface with ATM networks)
- Ethernet 2/0 interface refers to the interface card 2 and port 0 in that card
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Index
Interface
IP address
Network Mask
Network Address
Link Address
23
LEC.1.0
192.168.3.1
255.255.255.0
192.168.3.0
0x00000C3920B4
25
LEC.3.9
192.168.252.15
255.255.255.0
192.168.252.0
0x00000C3920B4
13
Ethernet2/0
172.16..46.1
255.255.255.0
172.16..46.0
0x00000C3920AC
16
Ethernet2/3
172.16.49.1
255.255.255.0
172.16.49.0
0x00000C3920AF
17
Ethernet2/4
172.16.52.1
255.255.255.0
172.16.52.0
0x00000C3920B0
9
Ethernet1/2
172.16.55.1
255.255.255.0
172.16.55.0
0x00000C3920A6
2
Ethernet 0/1
172.16.56.1
255.255.255.0
172.16.56.0
0x00000C39209D
15
Ethernet2/2
172.16.57.1
255.255.255.0
172.16.57.0
0x00000C3920AE
8
Ethernet1/1
172.16.58.1
255.255.255.0
172.16.58.0
0x00000C3920A5
14
Ethernet2/1
172.16.60.1
255.255.255.0
172.16.60.0
0x00000C3920AD
LAN emulation (LANE) is a group of software components that allows ATM to work with legacy networks and applications. With LAN emulation, you can run your traditional LAN-aware applications and protocols on an ATM network without modification.
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History of Internet SNMP Management
- 1970s Advanced Research Project Agency Network
(ARPANET) Internet Control Message Protocol (ICMP) - Internet Engineering Task Force (IETF)
- 1990 SNMPv1
- 1995 SNMPv2
- 1998 SNMPv3
- Internet documents:
- Request for Comments (RFC)
- IETF STD Internet Standard: (standards)
- FYI For Your Information: documents overviews and introductory topics
- Source for RFCs
- ftp://nic.mil/rfc
- ftp://ftp.internic.net/rfc
- http://nic/internet.net/
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
SNMPv1 & SNMPv2
Documents
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Figure 4.4 SNMP Document Evolution
SNMP Model
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
- Organization Model
- Relationship between network element, agent, and manager
- Hierarchical architecture
- Information Model
- Uses ASN.1 syntax
- SMI (Structure of Management Information)
- MIB ( Management Information Base)
- Communication Model
- Transfer syntax
- SNMP over TCP/IP
- Communication services addressed by messages
- Security framework community-based model
- Functional model
- Fault management
- Configuration management
- Account management
- Performance management
- Security management
Two-Tier Organization Model
- Any host that could query an agent is a manager.
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
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Figure 4.5 Two-Tier Organization Model
Three-Tier Organization Model:
RMON
- Managed object comprises network element and management agent
- RMON acts as an agent and a manager
- RMON (Remote Monitoring ) probe gathers data from MO, analyses the data, and stores the data
- Communicates the statistics to the manager
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
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Figure 4.6 Three-Tier Organization Model
heyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
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Three-Tier Organization Model:
Proxy Server
- Proxy server converts non-SNMP data from non-SNMP objects to SNMP compatible objects and messages
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Figure 4.7 Proxy Server Organization Model
Management System Architecture
- Messages between manager and agent
- Direction of messages - 3 from manager and
2 from agent
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
The Management System Architecture shows the types of Messages between manager and agent
The Management System Architecture shows the types of Messages between manager and agent
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Information model
- Information model deals with:
- Structure of Management Information (SMI) (RFC 1155)
- Specifies the structure of management information (Syntax and semantics) using a subset of ASN.1
- Management Information Base (RFC 1213)
- Specifies organization of management information in a hierarchical tree-like structure
- Each object in the MIB (node of the tree) is addressed through an object identifier (OID).
- RFCs can be downloaded from ftp.internic.net/rfc
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
For information to be efficiently exchanged between managers and agents, there has to be common understanding for both syntax and semantics
- Managed Object
- Scalar
- Aggregate or tabular object
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Notes
Management Information Base (MIB)
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- Information base contains information about objects
- Organized by grouping of related objects
- Defines relationship between objects
- It is NOT a physical database. It is a virtual database that is compiled into management module
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
MIB View and Access of an Object
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- A managed object has many attributes which compose its management information base
- There are several operations that can be performed on the objects
- A user (manager) can view and perform only certain operations on the object by invoking the management agent
- The view of the object attributes that the agent perceives is the MIB view
- The operation that a user can perform is the MIB access
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Managed Object
- Object type and data type are synonymous
- Object identifier is data type, not instance
- Object instance IP address (See Figure 4.2)
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
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Managed Object: Multiple Instances
- All 3 Com hubs of the same version have identical identifier; they are distinguished by the IP address.
- Each IP address is an instance of the object IP address.
- Basic Encoding Rules
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Name
Uniquely defined by
- DESCRIPTOR AND
- OBJECT IDENTIFIER
Example of name: ipAddrTable ip 20
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
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Internet as an organization has an object name and only one instance:
Watch the case
OSI Management Information Tree
The managed objects are uniquely defined by a tree structure specified by the OSI model
Change “standard” by “org” in the left list of addresses.
internet OBJECT IDENTIFIER ::=
{iso org(3) dod(6) 1 }.
internet OBJECT IDENTIFIER ::= {iso(1) standard(3) dod(6) internet(1)}
internet OBJECT IDENTIFIER ::= {1 3 6 1}
internet OBJECT IDENTIFIER ::= {iso standard dod internet } internet OBJECT IDENTIFIER ::= { iso standard dod(6) internet(1) }
internet OBJECT IDENTIFIER ::= { iso(1) standard(3) 6 1 }
Mnemonic=a device such as a pattern of letters, ideas, or associations that assists in remembering something.
OSI Management Information Tree is nearly the equivqlent of the MIB tree for snmp
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Internet Subnodes
- directory OBJECT IDENTIFIER ::= {internet 1}
mgmt OBJECT IDENTIFIER ::= {internet 2}
experimental OBJECT IDENTIFIER ::= {internet 3}
private OBJECT IDENTIFIER ::= {internet 4}
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Private MIB Example
- private MIB intended for vendor equipment
- IANA (Internet Assigned Numbers Authority)
assigns identifiers
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Notes
Notes
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Chapter 3 Basic Foundations: Standards, Models, and Language
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- ASN.1 is more than a syntax; it’s a language Addresses both syntax and semantics
- Two types of syntax
- Abstract syntax: set of rules that specify data type and structure for information storage
- Transfer syntax: set of rules for communicating information between systems
- Makes application layer protocols independent of lower layer protocols
- Can generate machine-readable code: Basic Encoding Rules (BER) is used in management modules
ASN.1 defines the abstract syntax of information but does not restrict the way the information is encoded
ASN.1 facilitates the exchange of structured data especially between application programs over networks by describing data structures in a way that is independent of machine architecture and implementation language.
In the previous sections, we discussed the information model and the communication model, a communication language is needed to specify syntax and semantics of the communication: formats and semantics for data transfer
ASN.1 is a formal language
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SNMP ASN.1 Data Type
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In general data types are defined basied on structure and tag
Primitive Data Types
- get-request message has NULL for value fields
and get-response from agent has the values filled
in subtype: - INTEGER (0..255)
- OCTET STRING (SIZE 0..255)
- OCTET STRING (SIZE 8)
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Notes
|
Structure |
Data Type |
Comments |
|
Primitive types |
INTEGER |
Subtype INTEGER (n1..nN) Special case: Enumerated INTEGER type |
|
|
OCTET STRING |
8-bit bytes binary and textual data Subtypes can be specified by either range or fixed |
|
|
OBJECT IDENTIFIER |
Object position in MIB |
|
|
NULL |
Placeholder |
octet
noun oc·tet \äk-ˈtet\
: a song or piece of music performed by eight singers or musicians
: a group of eight singers or musicians who perform an octet
48 words to make in SCRABBLE ® with Q and no U »
Full Definition of OCTET
1
: a musical composition for eight instruments or voices
2
: a group or set of eight: as
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Enumerated
- noError NULL by convention
- Special case of INTEGER data type
- Example:
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error-status INTEGER {
noError(0)
tooBig(1)
genErr(5)
authorizationError(16)
}
Defined or Application Data Type
- Defined data types are simple or base types
- Opaque is used to create data types based on
previously defined data types
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These are the defined or application datatype each one has a specification, read and remember them
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Constructor or Structured Data Type: SEQUENCE
- List maker
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If=interface
ipAdEntReasmMaxsize = maximum size for packets reassembling
SEQUENCE { <type1>, <type2>,…, <typeN> }
Object
OBJECT IDENTIFIER
ObjectSyntax
1
ipAdEntAddr
{ipAddrEntry 1}
IpAddress
2
ipAdEntIfIndex
{ipAddrEntry 2}
INTEGER
3
ipAdEntNetMask
{ipAddrEntry 3}
IpAddress
4
ipAdEntBcastAddr
{ipAddrEntry 4}
INTEGER
5
ipAdEntReasmMaxSize
{ipAddrEntry 5}
INTEGER
6
ipAddrEntry
{ipAddrTable 1}
SEQUENCE
List: IpAddrEntry ::=
SEQUENCE {
ipAdEntAddr IpAddress
ipAdEntIfIndex INTEGER
ipAdEntNetMask IpAddress
ipAdEntBcastAddr INTEGER
ipAdEntReasmMaxSize INTEGER (0..65535)
}
Managed Object IpAddrEntry as a list
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Constructor or Structured Data Type: SEQUENCE OF
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Allows to create a table = “rows of lists”
Columnar Objects
Object Name
OBJECT IDENTIFIER
Syntax
7
ipAddrTable
{ip 20}
SEQUENCE OF
Table: IpAddrTable ::=
SEQUENCE OF IpAddrEntry
Managed Object ipAddrTable as a table
SEQUENCE OF Example
- The above example (Figure 4.3) uses part of the IP MIB discussed for SEQUENCE OF construct.
- Each row of the table is a sequence of (index, interface, Ip address, net mask, net address, link address )
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Title: System Information : router1.gatech.edu
Name or IP Address: 172.16252.1
Index
Interface
IP address
Network Mask
Network Address
Link Address
23
LEC.1.0
192.168.3.1
255.255.255.0
192.168.3.0
0x00000C3920B4
25
LEC.3.9
192.168.252.15
255.255.255.0
192.168.252.0
0x00000C3920B4
13
Ethernet2/0
172.16..46.1
255.255.255.0
172.16..46.0
0x00000C3920AC
16
Ethernet2/3
172.16.49.1
255.255.255.0
172.16.49.0
0x00000C3920AF
17
Ethernet2/4
172.16.52.1
255.255.255.0
172.16.52.0
0x00000C3920B0
9
Ethernet1/2
172.16.55.1
255.255.255.0
172.16.55.0
0x00000C3920A6
2
Ethernet 0/1
172.16.56.1
255.255.255.0
172.16.56.0
0x00000C39209D
15
Ethernet2/2
172.16.57.1
255.255.255.0
172.16.57.0
0x00000C3920AE
8
Ethernet1/1
172.16.58.1
255.255.255.0
172.16.58.0
0x00000C3920A5
14
Ethernet2/1
172.16.60.1
255.255.255.0
172.16.60.0
0x00000C3920AD
Encoding
- SNMP Data Types and Tags
Type Tag
OBJECT IDENTIFIER UNIVERSAL 6
SEQUENCE UNIVERSAL 16
IpAddress APPLICATION 0
Counter APPLICATION 1
Gauge APPLICATION 2
TimeTicks APPLICATION 3
Opaque APPLICATION 4
- Basic Encoding Rules (BER)
- Type, Length, and Value (TLV)
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- TLV Type, length, and value are components of the structure
P=primitive\c=construct
In computers, encoding is the process of putting a sequence of characters (letters, numbers, punctuation, and certain symbols) into a specialized format for efficient transmission or storage.
Class
8th bit
7th bit
Universal
0
0
Application
0
1
Context-specific
1
0
Private
1
1
Basic encoding rules (BER)
In computers, encoding is the process of putting a sequence of characters (letters, numbers, punctuation, and certain symbols) into a specialized format for efficient transmission or storage.
Decoding is the opposite process -- the conversion of an encoded format back into the original sequence of characters. Encoding and decoding are used in data communications, networking, and storage
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Encoding
- Basic Encoding Rules (BER)
- Type, Length, and Value (TLV)
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Notes
Within data communication protocols, optional information may be encoded as a type-length-value or TLV element inside a protocol. TLV is also known as tag-length value.
The type and length are fixed in size (typically 1-4 bytes), and the value field is of variable size. These fields are used as follows:
- Type
A binary code, often simply alphanumeric, which indicates the kind of field that this part of the message represents;
- Length
The size of the value field (typically in bytes);
- Value
Variable-sized series of bytes which contains data for this part of the message.
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Managed Object: Structure
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OBJECT: sysDescr: { system 1 } Syntax: OCTET STRING Definition: "A textual description of the entity. This value should include the full name and version identification of the system's hardware type, software operating-system, and networking software. It is mandatory that this only contain printable ASCII characters." Access: read-only Status: mandatory
Figure 4.17 Specifications for System Description
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Managed Object: Macro
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OBJECT-TYPE MACRO ::=
BEGIN
TYPE NOTATION ::= “SYNTAX” type(TYPE ObjectSyntax)
“ACCESS” Access
“STATUS” Status
VALUE NOTATION ::= value(VALUE ObjectName)
Access ::= “read-only” | “read-write” | “write-only” | “not-accessible”
Status ::= “mandatory” | “optional” | “obsolete”
END
Figure 4.18(a) OBJECT-TYPE Macro [RFC 1155]
sysDescr OBJECT-TYPE
SYNTAX DisplayString (SIZE (0..255))
ACCESS read-only
STATUS mandatory
DESCRIPTION
“A textual description of the entity. This value should include the full name and version identification of the system’s hardware type, software operating-system, and networking software. It is mandatory that this only contain printable ASCII characters.”
::= {system 1 }
Figure 4.18(b) Scalar or Single Instance Macro: sysDescr
[RFC 1213]
Defined as
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- A group of objects
- Also called tabular objects
- Can be represented by a table with
- Columns of objects
- Rows of instances
- Example: IP address table
- table Consists of objects:
- IP address
- Interface
- Subnet mask (which subnet this address belongs to)
- Broadcast address (value of l.s.b. in IP broadcast address)
- Largest IP datagram that can be assembled
- Multiple instances of these objects associated with the node
Table of Objects
List of Objects
Objects
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A table is a sequence of lists of objects
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Aggregate M.O. Macro: Table Object
ipAddrTable OBJECT-TYPE
::= {ip 20}
ipAddrEntry OBJECT-TYPE
::= {ipAddrTable 1}
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- The ipAddrTable corresponds to the node 20 under the node ip.
- The ipAddrEntry is a node under the node of its table
ipAddrTable OBJECT-TYPE
SYNTAX SEQUENCE OF IpAddrEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"The table of addressing information relevant to this entity's IP addresses."
::= {ip 20}
Aggregate M.O. Macro: Entry Object
- Index ipAdEntAddr uniquely identifies an instance
- May require more than one object in the instance to
uniquely identify it
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ipAddrEntry OBJECT-TYPE
SYNTAX IpAddrEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"The addressing information for one of this entity's IP addresses."
INDEX { ipAdEntAddr }
::= { ipAddrTable 1 }
IpAddrEntry ::=
SEQUENCE {
ipAdEntAddr
IpAddress,
ipAdEntIfIndex
INTEGER,
ipAdEntNetMask
IpAddress,
ipAdEntBcastAddr
INTEGER,
ipAdEntReasmMaxSize
INTEGER (0..65535)
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Aggregate M.O. Macro: Columnar Objects
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- Members of the ipAddrEntry are defined sa nodes under the node of its ipAddrEntry
ipAdEntAddr OBJECT-TYPE
SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The IP address to which this entry's addressing information pertains."
::= { ipAddrEntry 1 }
ipAdEntReasmMaxSize OBJECT-TYPE
SYNTAX INTEGER (0..65535)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The size of the largest IP datagram which this entity can re-assemble from incoming IP fragmented datagrams received on this interface."
::= { ipAddrEntry 5 }
Tabular Representation of Aggregate Object
- The objects TABLE T and ENTRY E are objects
that are logical objects. They define the
grouping and are not accessible. - Columnar objects are objects that represent the
attributes and hence are accessible. - Each instance of E is a row of columnar objects
1 through 5. - Multiple instances of E are represented by
multiple rows.
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Aggregate Object have a Tabular Representation
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Tabular Representation of
Aggregate Object (cont.)
- Notice that the column-row numeric designation
is reverse of what we are used to as row-column
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Multiple Instances of Aggregate Managed Object
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ipAddrTable {1.3.6.1.2.1.4.20}
ipAddrEntry (1)
ipAdEntAddr (1)
ipAdEntIfIndex (2)
ipAdEntNetMask (3)
ipAdEntBcastAddr (4)
ipAdEntReasmMaxSize (5)
Columnar object ID of ipAdEntBcastAddr is (1.3.6.1.2.1.4.20.1.4):
iso org dod internet mgmt mib ip ipAddrTable ipAddrEntry ipAdEntBcastAddr
1 3 6 1 2 1 4 20 1 4
Figure 4.23(a) Columnar objects under ipAddrEntry
|
Row |
ipAdEntAddr |
ipAdEntIfIndex |
IpAdEntNetMask |
IpAdEntBcastAddr |
IpAdEntReasmMaxSize
|
|
1 |
123.45.2.1 |
1 |
255.255.255.0 |
0 |
12000 |
|
2 |
123.45.3.4 |
3 |
255.255.0.0 |
1 |
12000 |
|
3 |
165.8.9.25 |
2 |
255.255.255.0 |
0 |
10000 |
|
4 |
9.96.8.138 |
4 |
255.255.255.0 |
0 |
15000 |
Figure 4.23(b) Object instances of ipAddrTable (1.3.6.1.2.1.4.20)
|
Columnar Object |
Row # in (b)
|
Object Identifier |
|
ipAdEntAddr 1.3.6.1.2.1.4.20.1.1 |
2 |
{1.3.6.1.2.1.4.20.1.1.123.45.3.4} |
|
ipAdEntIfIndex 1.3.6.1.2.1.4.20.1.2 |
3 |
{1.3.6.1.2.1.4.20.1.2.165.8.9.25} |
|
ipAdEntBcastAddr 1.3.6.1.2.1.4.20.1.4 |
1 |
{1.3.6.1.2.1.4.20.1.4.123.45.2.1} |
|
IpAdEntReasmMaxSize 1.3.6.1.2.1.4.20.1.5 |
4 |
{1.3.6.1.2.1.4.20.1.5.9.96.8.138} |
Figure 4.23(c) Object Id for specific instance
*
SMI Definition STD 16 / 1155 RFC
- EXPORTS identifies the objects that any other module could import.
Network Management: Principles and Practice
© Mani Subramanian 2010
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
The formalized definitions of SMI as presented in STD 16/RFC 1155 is shown here.
In addition to the definition of the object type macro, it also specifies the exports of names and object types, as well as the Internet MIB, which is addressed in the next section.
RFC1155-SMI DEFINITIONS ::= BEGIN
EXPORTS -- EVERYTHING
internet, directory, mgmt, experimental, private, enterprises,
OBJECT-TYPE, ObjectName, ObjectSyntax, SimpleSyntax,
ApplicationSyntax, NetworkAddress, IpAddress, Counter, Gauge,
TimeTicks, Opaque;
-- the path to the root
internet OBJECT IDENTIFIER ::= { iso org(3) dod(6) 1 }
directory OBJECT IDENTIFIER ::= { internet 1 }
mgmt OBJECT IDENTIFIER ::= { internet 2 }
experimental OBJECT IDENTIFIER ::= { internet 3 }
private OBJECT IDENTIFIER ::= { internet 4 }
enterprises OBJECT IDENTIFIER ::= { private 1 }
SMI Definition STD 16 / 1155 RFC (cont.)
Network Management: Principles and Practice
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*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
-- definition of object types
OBJECT-TYPE MACRO ::=
BEGIN
TYPE NOTATION ::= "SYNTAX" type (TYPE ObjectSyntax)
"ACCESS" Access
"STATUS" Status
VALUE NOTATION ::= value (VALUE ObjectName)
Access ::= "read-only" | "read-write" | "write-only" | "not-accessible"
Status ::= "mandatory" | "optional" | "obsolete"
END
SMI Definition STD 16 / 1155 RFC (cont.)
Network Management: Principles and Practice
© Mani Subramanian 2010
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
-- names of objects in the MIB
ObjectName ::=
OBJECT IDENTIFIER
-- syntax of objects in the MIB
ObjectSyntax ::=
CHOICE {
simple
SimpleSyntax,
application-wide
ApplicationSyntax
}
SMI Definition STD 16 / 1155 RFC (cont.)
Network Management: Principles and Practice
© Mani Subramanian 2010
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
SimpleSyntax ::=
CHOICE {
number
INTEGER,
string
OCTET STRING,
object
OBJECT IDENTIFIER,
empty
NULL
}
ApplicationSyntax ::=
CHOICE {
address
NetworkAddress,
counter
Counter,
gauge
Gauge,
ticks
TimeTicks,
arbitrary
Opaque
-- other application-wide types, as they are defined, will be added here
}
SMI Definition STD 16 / 1155 RFC (cont.)
Network Management: Principles and Practice
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
-- application-wide types
NetworkAddress ::=
CHOICE {
internet
IpAddress
}
IpAddress ::=
[APPLICATION 0] -- in network-byte order
IMPLICIT OCTET STRING (SIZE (4))
Counter ::=
[APPLICATION 1]
IMPLICIT INTEGER (0..4294967295)
Gauge ::=
[APPLICATION 2]
IMPLICIT INTEGER (0..4294967295)
TimeTicks ::=
[APPLICATION 3]
IMPLICIT INTEGER (0..4294967295)
Opaque ::=
[APPLICATION 4] -- arbitrary ASN.1 value,
IMPLICIT OCTET STRING -- "double-wrapped"
END
MIB
- MIB-II (RFC 1213) is superset of MIB-I.
- Objects that are related grouped into object groups.
- MIB module comprises module name, imports from
other modules, and definitions of current module. - RFC 1213 defines eleven groups; expanded later.
Network Management: Principles and Practice
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*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
MIB
Network Management: Principles and Practice
© Mani Subramanian 2010
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
System Group
Network Management: Principles and Practice
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*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Entity
OID
Description (brief)
sysDescr XE "sysDescr"
system 1
Textual description
sysObjectID XE "sysObjectID"
system 2
OBJECT IDENTIFIER of the entity
sysUpTime XE "sysUpTime"
system 3
Time (in hundredths of a second since last reset)
sysContact XE "sysContact"
system 4
Contact person for the node
sysName
system 5
Administrative name of the system
sysLocation XE "sysLocation"
system 6
Physical location of the node
sysServices XE "sysServices"
system 7
Value designating the layer services provided by the entity
sysServices
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*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
sysServices OBJECT-TYPE
SYNTAX INTEGER (0..127)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A value which indicates the set of services that
this entity primarily offers.
The value is a sum. This sum initially takes the
value zero, Then, for each layer, L, in the range
1 through 7, that this node performs transactions
for, 2 raised to (L - 1) is added to the sum. For
example, a node which performs primarily routing
functions would have a value of 4 (2^(3-1)). In
contrast, a node which is a host offering
application services would have a value of 72
(2^(4-1) + 2^(7-1)). Note that in the context of
the Internet suite of protocols, values should be
calculated accordingly:
layer functionality
1 physical (e.g., repeaters)
2 datalink/subnetwork (e.g., bridges)
3 internet (e.g., IP gateways)
4 end-to-end (e.g., IP hosts)
7 applications (e.g., mail relays)
For systems including OSI protocols, layers 5 and
6 may also be counted."
::= { system 7 }
Interfaces Group
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Extension to Interfaces MIB
Network Management: Principles and Practice
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- Interfaces MIB limited by maximum number of physical ports
- A physical port may have several conceptual ports
e.g., channels in cable access network - ifMIB {mib-2 31} created to extend interfaces MIB
- ifMIB speicifies extension in generic manner
- Specific technology related MIBs supplement details on the
conceptual ports - ifIndex in interfaces MIB can exceed the maximum number of
physical ports - ifStack definition accommodates interface sublayers
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Interface Sublayers
Network Management: Principles and Practice
© Mani Subramanian 2010
Figure 4.29 Interface Sublayers
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
DLL can be visualized, in general, as comprising several sublayers. These can either be horizontally
stacked or vertically sliced (or “stacked”), as shown in Figures 4.29(a) and (b), respectively. An example
of the former is an interface with PPP running over a High data rate Digital Subscriber Line (HDLC)
link, which uses an RS232-like connector. An example of the latter is a cable access link with a down-
stream channel and several upstream channels.
ifEntry
- ifEntry specifies the objects in a row in the ifTable.
- Each interface is defined as a row in the table.
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
IfEntry OBJECT-TYPE
SYNTAX IfEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"An interface entry containing objects at the subnetwork layer and below for a particular interface."
INDEX {ifIndex}
::= {ifTable 1}
ifType
- Type of interface below the network layer defined
as enumerated integer.
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
ifType OBJECT-TYPE
SYNTAX INTEGER {
other(1), -- none of the following
regular1822(2),
hdh1822(3),
ddn-x25(4),
rfc877-x25(5),
ethernet-csmacd(6),
iso88023-csmacd(7),
iso88024-tokenBus(8),
iso88025-tokenRing(9),
iso88026-man(10),
starLan(11),
proteon-10Mbit(12),
proteon-80Mbit(13),
hyperchannel(14),
fddi(15),
lapb(16),
sdlc(17),
ds1(18), -- T-1
e1(19), -- european equiv. of T-1
basicISDN(20),
primaryISDN(21), -- proprietary serial
propPointToPointSerial(22),
ppp(23),
……….
IP Group
- ipForwarding: Gateway(1) and Router(2)
- IP Address Table contains table of IP addresses
- IP Route Table contains an entry for each route
- IP Network-to-Media Table is address translation table
mapping IP addresses to physical addresses
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
IP Address Table
Network Management: Principles and Practice
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Entity
OID
Description (brief)
ipAddrTable
ip 20
Table of IP addresses
ipAddrEntry
IpAddrTable 1
One of the entries in the IP address table
ipAdEntAddr
IpAddrEntry 1
The IP address to which this entry's addressing information pertains
ipAdEntIfIndex
IpAddrEntry 2
Index value of the entry, same as ifIndex
ipAdEntNetMask
IpAddrEntry 3
Subnet mask for the IP address of the entry
ipAdEntBcastAddr
IpAddrEntry 4
Broadcast address indicator bit
ipAdEntReasmMaxSize
IpAddrEntry 5
Largest IP datagram that can be reassembled on this interface
IP Routing Table
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Entity
OID
Description (brief)
ipRouteTable
ip 21
IP routing table
ipRouteEntry
ipRouteTable 1
Route to a particular destination
ipRouteDest
ipRouteEntry 1
Destination IP address of this route
ipRouteIfIndex
ipRouteEntry 2
Index of interface, same as ifIndex
ipRouteMetric1
ipRouteEntry 3
Primary routing metric for this route
ipRouteMetric2
ipRouteEntry 4
An alternative routing metric for this route
ipRouteMetric3
ipRouteEntry 5
An alternative routing metric for this route
ipRouteMetric4
ipRouteEntry 6
An alternative routing metric for this route
ipRouteNextHop
ipRouteEntry 7
IP address of the next hop
ipRouteType
ipRouteEntry 8
Type of route
ipRouteProto
ipRouteEntry 9
Routing mechanism by which this route was learned
ipRouteAge
ipRouteEntry 10
Number of seconds since routing was last updated
ipRouteMask
ipRouteEntry 11
Mask to be logically ANDed with the destination address before comparing with the ipRouteDest field
ipRouteMetric5
ipRouteEntry 12
An alternative metric for this route
ipRouteInfo
ipRouteEntry 13
Reference to MIB definition specific to the routing protocol
IP Address Translation Table
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Entity
OID
Description (brief)
ipNetToMediaTable
ip 22
Table mapping IP addresses to physical addresses
ipNetToMediaEntry
IpNetToMediaTable 1
IP address to physical address for the particular interface
ipNetToMediaIfIndex
IpNetToMediaEntry 1
Interfaces on which this entry's equivalence is effective; same as ifIndex
ipNetToMediaPhysAddress
IpNetToMediaEntry 2
Media dependent physical address
ipNetToMediaNetAddress
IpNetToMediaEntry 3
IP address
ipNetToMediaType
IpNetToMediaEntry 4
Type of mapping
ICMP Group
- Objects associated with ping
- icmpOutEchos # ICMP echo messages sent
- icmpInEchoReps # ICMP echo reply messages
received - Objects associated with traceroute/tracert
- icmpInTimeExcs # ICMP time exceeded messages received
Network Management: Principles and Practice
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Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
TCP Group
- Connection-oriented transport protocol group
- Has one table
Network Management: Principles and Practice
© Mani Subramanian 2010
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
TCP Connection Table
Network Management: Principles and Practice
© Mani Subramanian 2010
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Entity
OID
Description (brief)
tcpConnTable
tcp 13
TCO connection table
tcpconnEntry
TcpConnTable 1
Information about a particular TCP connection
tcpConnState
TcpConnEntry 1
State of the TCP connection
tcpConnLocalAddress
TcpConnEntry 2
Local IP address
tcpConnLocalPort
TcpConnEntry 3
Local port number
tcpConnRemAddress
TcpConnEntry 4
Remote IP address
tcpConnRemPort
TcpConnEntry 5
Remote port number
UDP Group
- Connectionless transport protocol group
- Has one table, UDP table
Network Management: Principles and Practice
© Mani Subramanian 2010
*
Chapter 4 SNMPv1 Network Management: Organization and Information Models
Notes
Entity
OID
Description (brief)
udpInDatagrams
udp 1
Total number of datagrams delivered to the users
udpNoPorts
udp 2
Total number of received datagrams for which there is no application
udpInErrors
udp 3
Number of received datagrams with errors
udpOutDatagrams
udp 4
Total number of datagrams sent
udpTable
udp 5
UDP Listener table
udpEntry
udpTable 1
Information about a particular connection or UDP listener
udpLocalAddress
udpEntry 1
Local IP address
udpLocalPort
udpEntry 2
Local UDP port
*
A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter, and by similar terms
*
A backbone is a larger transmission line that carries data gathered from smaller lines that interconnect with it.
*
it is often referred to as hardware or physical address. MAC addresses are 6-byte (48-bits) in length, and are written in MM:MM:MM:SS:SS:SS format. The first 3-bytes are ID number of the manufacturer, which is assigned by an Internet standards body. The second 3-bytes are serial number assigned by the manufacturer.
MAC layer represents layer 2 of the TCP/IP (adopted from OSI Reference Model), where IP represents layer 3. MAC address can be thought of as supporting hardware implementation whereas IP address supports software implementation. MAC addresses are permanently burned into hardware by hardware manufacturer, but IP addresses are assigned to the network devices by a network administrator. DHCP relies on MAC address to assign IP addresses to network devices.
*
LAN emulation (LANE) is a group of software components that allows ATM to work with legacy networks and applications. With LAN emulation, you can run your traditional LAN-aware applications and protocols on an ATM network without modification.
*******
*
heyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
*
The Management System Architecture shows the types of Messages between manager and agent
*
- Managed Object
- Scalar
- Aggregate or tabular object
*
Mnemonic=a device such as a pattern of letters, ideas, or associations that assists in remembering something.
OSI Management Information Tree is nearly the equivqlent of the MIB tree for snmp
*
In the previous sections, we discussed the information model and the communication model, a communication language is needed to specify syntax and semantics of the communication: formats and semantics for data transfer
ASN.1 is a formal language
*
octet
noun oc·tet \äk-ˈtet\
: a song or piece of music performed by eight singers or musicians
: a group of eight singers or musicians who perform an octet
48 words to make in SCRABBLE ® with Q and no U »
Full Definition of OCTET
1
: a musical composition for eight instruments or voices
2
: a group or set of eight: as
*
These are the defined or application datatype each one has a specification, read and remember them
*
*
Basic encoding rules (BER)
In computers, encoding is the process of putting a sequence of characters (letters, numbers, punctuation, and certain symbols) into a specialized format for efficient transmission or storage.
Decoding is the opposite process -- the conversion of an encoded format back into the original sequence of characters. Encoding and decoding are used in data communications, networking, and storage
*
*
*
Defined as
*
*
*
Aggregate Object have a Tabular Representation
*
*
172.16.46.1
Backbone Network
Hub 1
172.16.46.2
Hub 2
172.16.46.3
Router 1
172.17.252.1
Router 2
NMS
192.168.252.110
Figure 4.1 Managed LAN Network
Title: System Information: 172.16.46.2
Name or IP Address: 172.16.46.2
System Name:
System Description: 3Com LinkBuilder FMS, SW version:3.02
System Contact:
System Location:
System Object ID: iso.org.dod.internet.private.enterprises.43.1.8.5
System Up Time: (2475380437) 286 days, 12:03:24.37
Figure 4.2(a) System Information on 172.16.46.2 Hub
Title: System Information: router1.gatech.edu
Name or IP Address: 172.16.252.1
System Name : router1.gatech.edu
System Description : Cisco Internetwork Operating System Software
: IOS (tm) 7000 Software (C7000 -JS-M), Version
: 11.2(6),RELEASE SOFTWARE (ge1)
: Copyright (c) 1986-1997 by Cisco Systems, Inc.
: Compiled Tue 06-May-97 19:11 by kuong
System Contact
System Location :
System Object ID : iso.org.dod.internet.private.enterprises.cisco.ciscoProducts.
cisco 7000
System Up Time : (315131795) 36 days, 11:21:57.95
Figure 4.2(c) System Information on Router
Index
Interface
IP address
Network Mask
Network
Address
Link Address
1
3Com
172.16.46.2
255.255.255.0
172.16 46.0
0x08004E07C25C
2
3Com
192.168.101.1
255.255.255.0
192.168.101.0
<none>
Index
Interface
IP address
Network Mask
Network
Address
Link Address
23
LEC.1.0
192.168.3.1
255.255.255.0
192.168.3.0
0x00000C3920B4
25
LEC.3.9
192.168.252.1
5
255.255.255.0
192.168.252.
0
0x00000C3920B4
13
Ethernet2/0
172.16
..46.1
255.255.255.0
172.16
..46.0
0x00000C3920AC
16
Ethernet2/3
172.16.49.1
255.255.255.0
172.16.49.0
0x00000C3920AF
17
Ethernet2/4
172.16.52.1
255.255.255.0
172.16.52.0
0x00000C3920B0
9
Ethernet1/2
172.16.55.1
255.255.255.0
172.16.55.0
0x00000C3920A6
2
Ethernet 0/1
172.16.56.1
255.255.255.0
172.16.56.0
0x00000C39209D
15
Ethernet2/2
172.16.57.1
255.255.255.0
172.16.57.0
0x00000C3920AE
8
Ethernet1/1
172.16.58.1
255.255.255.0
172.16.58.0
0x00000C3920A5
14
Ethernet2/1
172.16.60.1
255.255.255.0
172.16.60.0
0x00000C3920AD
RFC 1067
SNMP
Management
Documents
RFC 1065
SMI
RFC 1155
STD 16
RFC 1066
MIB I
RFC 1156
RFC 1098
SNMPv1
RFC 1157
STD 15
Concise SMI
RFC 1212
STD 16
SNMPv1
Traps
RFC 1215
RFC 1442
RFC 1902
RFC 1443
RFC 1903
RFC 1444
RFC 1904
RFC 1158
MIB II
RFC 1213
STD 17
RFC 1448
RFC 1905
RFC 1449
RFC 1906
RFC 1907
SMIv2
RFC 2578
SMIv2 Txt
Conventions
RFC 2579
SMIv2
Conformances
RFC 2580
MIB II for
SNMPv2
RFC 3418
SNMPv2
Protocol Ops
RFC 3416
SNMPv2
Transport Map.
RFC 3417
Network
Element
SNMPAgent
SNMP
Manager
Network
Element
Network Agent
SNMP
Manager
SNMP
Manager
(a) One Manager-One Agent Model
(b) Multiple Managers-One Agent Model
Manager
Managed objects
Unmanaged objects
Figure 3.2 Two-Tier Network Management Organization Model
Agent process
MDB
MDB Management Database
Managed
Objects
SNMP
Manager
RMON
Probe
Non-SNMP
Managed
Objects
SNMP
Manager
Proxy
Server
SNMP
Managed
Objects
SNMP Manager
Application
Get-Response
Get-Request
GetNext-Request
Set-Request
Trap
SNMP Manager
SNMP
UDP
IP
DLC
PHY
SNMP Agent
Application
Get-Response
Trap
SNMP Agent
SNMP
UDP
IP
DLC
PHY
Physical Medium
Figure 4.9 SNMP Network Management Architecture
Manage-
ment
Data
Get-Request
GetNext-Request
Set-Request
Object
Object
Instance
Object
Type
Encoding:
BER
Syntax:
ASN.1
Name:
OBJECT
IDENTIFIER
Figure 4.10 Managed Object : Type and Instance
Object
Object
Instance 3
Object
Type
Encoding:
BER
Syntax:
ASN.1
Name:
OBJECT
IDENTIFIER
Figure 4.11 Managed Object : Type with Multiple Instances
Object
Instance 2
Object
Instance 1
internet OBJECT IDENTIFIER ::=
{
iso org(3)
dod(6) 1 }.
internet OBJECT IDENTIFIER ::= {
iso(1) standard(3)
dod(6) internet(1)}
internet OBJECT IDENTIFIER ::= {1 3 6 1}
internet OBJECT IDENTIFIER ::= {
iso standard
dod internet }
internet OBJECT IDENTIFIER ::= {
iso standard
dod(6) internet(1) }
internet OBJECT IDENTIFIER ::= {
iso(1) standard(3) 6 1 }
iso-itu
2
itu
0
iso
1
org
3
dod
6
internet
1
Figure 3.8
OSI Management Information Tree
mgmt
(2)
directory
(1)
experimental
(3)
private
(4)
Internet
{1 3 6 1}
Figure 4.13 Subnodes under Internet Node in SNMPv1
enterprises
(1)
private
(4)
hp
(11)
cisco
(9)
3Com
(43)
Cabletron
(52)
Figure 4.14 Private Subtree for Commercial Vendors
internet
{1 3 6 1}
SNMP ASN.1
Data Type
Defined
or
Application
Constructor
or
Structured
Simple
or
Primitive
Number
Tag
Structure
Class
Universal
Application
Context-
specific
Private
Figure 4.15 SNMP ASN.1 Data Type
Structure Data Type Comments
Primitive types INTEGER Subtype INTEGER (n1..nN)
Special case: Enumerated
INTEGER type
OCTET STRING 8-bit bytes binary and textual data
Subtypes can be specified by
either range or fixed
OBJECT IDENTIFIER Object position in MIB
NULL Placeholder
error-status INTEGER {
noError(0)
tooBig(1)
genErr(5)
authorizationError(16)
}
SEQUENCE { <type1>, <type2>,…, <
typeN> }
Object
OBJECT IDENTIFIER
ObjectSyntax
1
ipAdEntAddr
{
ipAddrEntry 1}
IpAddress
2
ipAdEntIfIndex
{
ipAddrEntry 2}
INTEGER
3
ipAdEntNetMask
{
ipAddrEntry 3}
IpAddress
4
ipAdEntBcastAddr
{
ipAddrEntry 4}
INTEGER
5
ipAdEntReasmMaxSize
{
ipAddrEntry 5}
INTEGER
6
ipAddrEntry
{ipAddrTable 1}
SEQUENCE
List:
IpAddrEntry
::=
SEQUENCE
{
ipAdEntAddr
IpAddress
ipAdEntIfIndex
INTEGER
ipAdEntNetMask
IpAddress
ipAdEntBcastAddr
INTEGER
ipAdEntReasmMaxSize
INTEGER (0..65535)
}
Managed Object
IpAddrEntry as a list
Object Name
OBJECT IDENTIFIER
Syntax
7
ipAddrTable
{
ip 20}
SEQUENCE OF
Table:
IpAddrTable ::=
SEQUENCE OF
IpAddrEntry
Managed Object
ipAddrTable as a table
Title: System Information : router1.gatech.edu
Name or IP Address: 172.16252.1
Index
Interface
IP address
Network Mask
Network
Address
Link Address
23
LEC.1.0
192.168.3.1
255.255.255.0
192.168.3.0
0x00000C3920B4
25
LEC.3.9
192.168.252.1
5
255.255.255.0
192.168.252.
0
0x00000C3920B4
13
Ethernet2/0
172.16..46.1
255.255.255.0
172.16..46.0
0x00000C3920AC
16
Ethernet2/3
172.16.49.1
255.255.255.0
172.16.49.0
0x00000C3920AF
17
Ethernet2/4
172.16.52.1
255.255.255.0
172.16.52.0
0x00000C3920B0
9
Ethernet1/2
172.16.55.1
255.255.255.0
172.16.55.0
0x00000C3920A6
2
Ethernet 0/1
172.16.56.1
255.255.255.0
172.16.56.0
0x00000C39209D
15
Ethernet2/2
172.16.57.1
255.255.255.0
172.16.57.0
0x00000C3920AE
8
Ethernet1/1
172.16.58.1
255.255.255.0
172.16.58.0
0x00000C3920A5
14
Ethernet2/1
172.16.60.1
255.255.255.0
172.16.60.0
0x00000C3920AD
Type
Length
Value
Class
(7-8th bits)
P/C
(6th bit)
Tag Number
(1-5th bits)
Class
8
th
bit
7
th
bit
Universal
0
0
Application
0
1
Context-specific
1
0
Private
1
1
OBJECT:
sysDescr: { system 1 }
Syntax: OCTET STRING
Definition: "A textual description of the entity. This value
should include the full name and version
identification of the system's hardware type,
software operating-system, and networking
software. It is mandatory that this only contain
printable ASCII characters."
Access: read-only
Status: mandatory
Figure 4.17 Specifications for System Description
sysServices (7)
sysLocation (6)
sysDescr (1)
system
(mib-2 1)
sysObjectId
(2)
sysUpTime (3)
sysName (5)
sysContact (4)
Figure 4.27 System Group
OBJECT-TYPE MACRO ::=
BEGIN
TYPE NOTATION ::= “SYNTAX” type(TYPE ObjectSyntax)
“ACCESS” Access
“STATUS” Status
VALUE NOTATION ::= value(VALUE ObjectName)
Access ::= “read-only” | “read-write” | “write-only” | “not-accessible”
Status ::= “mandato ry” | “optional” | “obsolete”
END
Figure 4.18(a) OBJECT-TYPE Macro [RFC 1155]
sysDescr OBJECT-TYPE
SYNTAX DisplayString (SIZE (0..255))
ACCESS read-only
STATUS mandatory
DESCRIPTION
“A textual description of the entity. This value should
include the full name and version identification of the
system’s hardware type, software operating-system, and
networking software. It is mandatory that this only
contain printable ASCII characters.”
::= {system 1 }
Figure 4.18(b) Scalar or Single Instance Macro: sysDescr
[RFC 1213]
ipAddrTable OBJECT-TYPE
SYNTAX SEQUENCE OF
IpAddrEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"The table of addressing
information relevant to this entity's IP
addresses."
::= {
ip 20}
ipAddrEntry OBJECT-TYPE
SYNTAX
IpAddrEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"The addressing information for one of this
entity's IP addresses."
INDEX
{
ipAdEntAddr }
::= {
ipAddrTable 1 }
IpAddrEntry
::=
SEQUENCE {
ipAdEntAddr
IpAddress,
ipAdEntIfIndex
INTEGER,
ipAdEntNetMask
IpAddress,
ipAdEntBcastAddr
INTEGER,
ipAdEntReasmMaxSize
INTEGER (0
..65535)
ipAdEntAddr OBJECT-TYPE
SYNTAX
IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The IP address to which this entry's
addressing information pertains."
::= {
ipAddrEntry 1 }
ipAdEntReasmMaxSize OBJECT-TYPE
SYNTAX INTEGER (0..65535)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The size of the largest IP
datagram which this
entity can re-assemble from incoming IP
fragmented
datagrams received on this interface."
::= {
ipAddrEntry 5 }
TABLE
T
ENTRY
E
COLUMNAR
OBJECT 1
COLUMNAR
OBJECT 5
COLUMNAR
OBJECT 2
COLUMNAR
OBJECT 3
COLUMNAR
OBJECT 4
Figure 4.22(a) Multiple Instance Managed Object
T
T.E
T.E.1.1
T.E.5.1
T.E.2.1
T.E.3.1
T.E.4.1
T.E.1.2
T.E.5.2
T.E.2.2
T.E.3.2
T.E.4.2
T.E.1.3
T.E.5.3
T.E.2.3
T.E.3.3
T.E.4.3
T.E.1.4
T.E.5.4
T.E.2.4
T.E.3.4
T.E.4.4
Figure 4.22(b) Example of 5 Columnar Object with 4 Instances (rows)
ipAddrTable {1.3.6.1.2.1.4.20}
ipAddrEntry (1)
ipAdEntAddr (1)
ipAdEntIfIndex (2)
ipAdEntNetMask (3)
ipAdEntBcastAddr (4)
ipAdEntReasmMaxSize (5)
Columnar object ID of ipAdEntBcastAddr is (1.3.6.1.2.1.4.20.1.4):
iso org dod internet mgmt mib ip ipAddrTable ipAddrEntry ipAdEntBcastAddr
1 3 6 1 2 1 4 20 1 4
Figure 4.23(a) Columnar objects under ipAddrEntry
Row
ipAdEntAddr
ipAdEntIfIndex IpAdEntNetMask IpAdEntBcastAddr IpAdEntReasmMaxSize
1
123.45.2.1
1 255.255.255.0 0 12000
2
123.45.3.4
3 255.255.0.0 1 12000
3
165.8.9.25
2 255.255.255.0 0 10000
4
9.96.8.138
4 255.255.255.0 0 15000
Figure 4.23(b) Object instances of ipAddrTable (1.3.6.1.2.1.4.20)
Columnar Object Row # in (b)
Object Identifier
ipAdEntAddr
1.3.6.1.2.1.4.20.1.1
2 {1.3.6.1.2.1.4.20.1.1.123.45.3.4}
ipAdEntIfIndex
1.3.6.1.2.1.4.20.1.2
3 {1.3.6.1.2.1.4.20.1.2.165.8.9.25}
ipAdEntBcastAddr
1.3.6.1.2.1.4.20.1.4
1 {1.3.6.1.2.1.4.20.1.4.12 3.45.2.1}
IpAdEntReasmMaxSize
1.3.6.1.2.1.4.20.1.5
4 {1.3.6.1.2.1.4.20.1.5.9.96.8.138}
Figure 4.23(c) Object Id for specific instance
RFC1155-SMI DEFINITIONS ::= BEGIN
EXPORTS -- EVERYTHING
internet, directory, mgmt, experimental, private, enterprises,
OBJECT-TYPE, ObjectName, ObjectSyntax, SimpleSyntax,
ApplicationSyntax, NetworkAddress, IpAddress, Counter, Gauge,
TimeTicks, Opaque;
-- the path to the root
internet OBJECT IDENTIFIER ::= { iso org(3) dod(6) 1 }
directory OBJECT IDENTIFIER ::= { in ternet 1 }
mgmt OBJECT IDENTIFIER ::= { internet 2 }
experimental OBJECT IDENTIFIER ::= { internet 3 }
private OBJECT IDENTIFIER ::= { internet 4 }
enterprises OBJECT IDENTIFIER ::= { priva te 1 }
-- definition of object types
OBJECT-TYPE MACRO ::=
BEGIN
TYPE NOTATION ::= "SYNTAX" type (TYPE ObjectSyntax)
"ACCESS" Access
"STATUS" Status
VALUE NOTATION ::= value (VALUE ObjectName)
Access ::= "read-only" | "read-write" | "write-only" | "not-accessible"
Status ::= "mandatory" | "optional" | "obsolete"
END
--
names of objects in the MIB
ObjectName
::=
OBJECT IDENTIFIER
--
syntax of objects in the MIB
ObjectSyntax
::=
CHOICE {
simple
SimpleSyntax,
application-wide
ApplicationSyntax
}
SimpleSyntax
::=
CHOICE {
number
INTEGER,
string
OCTET STRING,
object
OBJECT IDENTIFIER,
empty
NULL
}
ApplicationSyntax
::=
CHOICE {
address
NetworkAddress,
counter
Counter,
gauge
Gauge,
ticks
TimeTicks,
arbitrary
Opaque
-- other application-wide types, as they are defined,
will be added here
}
--
application-wide types
NetworkAddress
::=
CHOICE {
internet
IpAddress
}
IpAddress
::=
[APPLICATION 0] -- in network-byte order
IMPLICIT OCTET STRING (SIZE (4))
Counter ::=
[APPLICATION 1]
IMPLICIT INTEGER (0
..4294967295)
Gauge ::=
[APPLICATION 2]
IMPLICIT INTEGER (0
..4294967295)
TimeTicks
::=
[APPLICATION 3]
IMPLICIT INTEGER (0
..4294967295)
Opaque ::=
[APPLICATION 4] -- arbitrary ASN.1 value,
IMPLICIT OCTET STRING -- "double-wrapped"
END
mgmt
(2)
directory
(1)
experimental
(3)
private
(4)
internet
{1 3 6 1}
mib-2
(1)
Figure 4.26 Internet MIB-II Group
system (1)
interfaces (2)
at (3)
ip (4)
icmp (5)
snmp (11)
transmission (10)
cmot (9)
egp (8)
udp (7)
tcp (6)
Entity
OID
Description (brief)
sysDescr
system 1
Textual description
sysObjectID
system 2
OBJECT IDENTIFIER of the entity
sysUpTime
system 3
Time (in hundredths of a second since last reset)
sysContact
system 4
Contact person for the node
sysName
system 5
Administrative name of the system
sysLocation
system 6
Physical location of the node
sysServices
system 7
Value designating the layer services provided by the
entity
sysServices OBJECT-TYPE
SYNTAX INTEGER (0..127)
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A value which indicates the set of services that
this entity primarily offers.
The value is a sum. This sum initially takes the
value zero, Then, for each layer, L, in the range
1 through 7, that this node performs transactions
for, 2 raised to (L - 1) is added to the sum. For
example, a node which performs primarily routing
functions would have a value of 4 (2^(3-1)). In
contrast, a node which is a host offering
application services would have a value of 72
(2^(4-1) + 2^(7-1)). Note that in the context of
the Internet suite of protocols, values should be
calculated accordingly:
layer functionality
1 physical (e.g., repeaters)
2
datalink/
subnetwork (e.g., bridges)
3 internet (e.g., IP gateways)
4 end-to-end (e.g., IP hosts)
7 applications (e.g., mail relays)
For systems including OSI protocols, layers 5 and
6 may also be counted."
::= { system 7 }
Legend:
INDEX in bold
ifTable
(2)
ifNumber
(1)
interfaces
(mib-2 2)
ifEntry
(1)
Figure 4.28 Interfaces Group
ifIndex (1)
ifDescr (2)
ifType (3)
ifMtu (4)
ifSpeed (5)
ifPhysAddress (6)
ifAdminstatus (7)
ifOperStatus (8)
ifLastChange (9)
ifInOctets (10)
ifInUcastPkts (11)
ifSpecific (22)
ifOutQLen (21)
ifOutErrors (20)
ifOutDiscards (19)
ifOutNUcastPkts (18)
ifOutUcastPkts (17)
ifOutOctets (16)
ifUnknownProtos (15)
ifInErrors (14)
ifInDiscards (13)
ifInNUcastPkts (12)
ifMIB
(31)
interfaces
(2)
mib-2
ifMIBObjects
(1)
ifXTable(1)
ifRcvAddressTable (4)
ifStackTable (2)
MAC Layer
interface Sublayer 1
interface Sublayer 2
interface Sublayer 3
Physical Layer
MAC Layer
Physical Layer
interface Sublayer 1
interface Sublayer 2
interface Sublayer 3
(a) Interface Stacked layers
(b) Interface Multiplexed layers
IfEntry
OBJECT-TYPE
SYNTAX
IfEntry
ACCESS
not-accessible
STATUS
mandatory
DESCRIPTION
"An interface entry containing
objects at the
subnetwork layer and
below for a particular interface."
INDEX
{
ifIndex}
::= {
ifTable 1}
ifType OBJECT-TYPE
SYNTAX INTEGER {
other(1), -- none of the following
regular1822(2),
hdh1822(3),
ddn-x25(4),
rfc877-x25(5),
ethernet-csmacd(6),
iso88023-csmacd(7),
iso88024-tokenBus(8),
iso88025-tokenRing(9),
iso88026-man(10),
starLan(11),
proteon-10Mbit(12),
proteon-80Mbit(13),
hyperchannel(14),
fddi(15),
lapb(16),
sdlc(17),
ds1(18), -- T-1
e1(19), --
european equiv. of T-1
basicISDN(20),
primaryISDN(21), -- proprietary serial
propPointToPointSerial(22),
ppp(23),
……….
ipRoutingDiscards (23)
ip
(mib-2 4)
ipForwarding (1)
ipDefaultTTL (2)
ipInReceives (3)
ipInHdrErrors (4)
ipInAddrErrors (5)
ipForwDatagrams (6)
ipInUnknownProtos (7)
ipInDiscards (8)
ipInDelivers (9)
ipOutRequests(10)
ipNetToMediaTable (22)
ipRouteTable (21)
ipAddrTable (20)
ipFragCreates (19)
ipFragFails (18)
ipFragOKs (17)
ipReasmFails (16)
ipReasmOKs (15)
ipReasmReqds (14)
ipOutDiscards (11)
ipReasmTimeout (13)
ipOutNoRoutes (12)
Figure 4.29 IP Group
Entity
OID
Description (brief)
ipAddrTable
ip 20
Table of IP addresses
ipAddrEntry
IpAddrTable 1
One of the entries in the IP address
table
ipAdEntAddr
IpAddrEntry 1
The IP address to which this entry's
addressing information pertains
ipAdEntIfIndex
IpAddrEntry 2
Index value of the entry, same as
ifIndex
ipAdEntNetMask
IpAddrEntry 3
Subnet mask for the IP address of
the entry
ipAdEntBcastAddr
IpAddrEntry 4
Broadcast address indicator bit
ipAdEntReasmMaxSize
IpAddrEntry 5
Largest IP datagram that can be
reassembled on this interface
ipAdEntAddr (1)
ipAddrEntry
(ipAddrTable 1)
ipAdEntReasmMaxSize (5)
ipAdEntBcastAddr (4)
Figure 4.30 IP Address Table
ipAddrTable
(ip 20)
ipAdEntIfIndex (2)
ipAdEntNetMask
(3)
Legend:
INDEX in bold
ipRouteEntry
ipRouteTable (1)
ipRouteDest
(1)
ipRouteIfIndex (2)
ipRouteMetric1 (3)
ipRouteMetric2 (4)
ipRouteMetric3 (5)
ipRouteInfo (13)
ipRouteMetric5
(12)
ipRouteMask 11)
ipRouteAge (10)
ipRouteProto (9)
ipRouteMetric4 (6)
ipRouteType (8)
ipRouteNextHop (7)
Figure 4.31 IP Routing Table
ipRouteTable
(ip 21)
Entity
OID
Description (brief)
ipRouteTable
ip 21
IP routing table
ipRouteEntry
ipRouteTable 1
Route to a particular destination
ipRouteDest
ipRouteEntry 1
Destination IP address of this route
ipRouteIfIndex
ipRouteEntry 2
Index of interface, same as
ifIndex
ipRouteMetric1
ipRouteEntry 3
Primary routing metric for this route
ipRouteMetric2
ipRouteEntry 4
An alternative routing metric for this route
ipRouteMetric3
ipRouteEntry 5
An alternative routing metric for this route
ipRouteMetric4
ipRouteEntry 6
An alternative routing metric for this route
ipRouteNextHop
ipRouteEntry 7
IP address of the next hop
ipRouteType
ipRouteEntry 8
Type of route
ipRouteProto
ipRouteEntry 9
Routing mechanism by which this route was
learned
ipRouteAge
ipRouteEntry 10
Number of seconds since routing was last updated
ipRouteMask
ipRouteEntry 11
Mask to be logically
ANDed with the destination
address before comparing with the
ipRouteDest
field
ipRouteMetric5
ipRouteEntry 12
An alternative metric for this route
ipRouteInfo
ipRouteEntry 13
Reference to MIB definition specific to the routing
protocol
ipNetToMediaTable
(ip 22)
ipNetToMediaEntry (1)
ipNetToMediaType (4)
ipNetToMediaIfIndex (1)
Figure 4.32 IP Address Translation Table
ipNetToMediaPhysAddress (2)
ipNetToMediaNetAddress
(3)
Entity
OID
Description (brief)
ipNetToMediaTable
ip 22
Table mapping IP addresses to
physical addresses
ipNetToMediaEntry
IpNetToMediaTable 1
IP address to physical address
for the particular interface
ipNetToMediaIfIndex
IpNetToMediaEntry 1
Interfaces on which this entry's
equivalence is effective; same
as ifIndex
ipNetToMediaPhysAddress
IpNetToMediaEntry 2
Media dependent physical
address
ipNetToMediaNetAddress
IpNetToMediaEntry 3
IP address
ipNetToMediaType
IpNetToMediaEntry 4
Type of mapping
Figure 4.34 ICMP Group
icmp
(mib-2 5)
icmpInMsgs (1)
icmpInErrors (2)
icmpInDestUnreachs (3)
icmpInTimeExcds (4)
icmpInParmProbe (5)
icmpInSrcQuenchs (6)
icmpInRedirects (7)
icmpInEchos (8)
icmpInEchoReps (9)
icmpInTimestamps (10)
icmpInTimestampReps (11)
icmpOutAddrMaskReps (26)
icmpOutAddrMasks (25)
icmpOutTimestampReps (24)
icmpOutTimestamps (23)
icmpOutEchoReps (22)
icmpOutEchos (21)
icmpOutRedirects (20)
icmpOutSrcQuenchs (19)
icmpOutParmProbe (18)
icmpOutTimeExcds (17)
icmpOutDestUnreachs (16)
icmpInAddrMasks (12)
icmpInAddrMaskReps (13)
icmpOutErrors (15)
icmpInMsgs (14)
tcp
(mib-2 6)
tcpRtoAlgorithm
(1)
tcpRtoMin (2)
tcpRtoMax (3)
tcpMaxConn (4)
tcpActiveOpens (5)
tcpOutRsts (15)
tcpInErrors (14)
tcpConnTable 13)
tcpRetranSegs (12)
tcpOutSegs (11)
tcpPassiveOpens (6)
tcpInSegs (10)
tcpCurrEstab (9)
tcpAttemptFails (7)
tcpEstabResets (8)
Figure 4.35 TCP Group
tcpConnEntry
(1)
tcpConnState (1)
tcpConnLocalAddress (2)
tcpCommRemPort (5)
tcpConnRemAddress(4)
tcpConnLocalPort (3)
tcpConnTable
(tcp 13)
Figure 4.36 TCP Connection Table
Entity
OID
Description (brief)
tcpConnTable
tcp 13
TCO connection table
tcpconnEntry
TcpConnTable 1
Information about a particular TCP
connection
tcpConnState
TcpConnEntry 1
State of the TCP connection
tcpConnLocalAddress
TcpConnEntry 2
Local IP address
tcpConnLocalPort
TcpConnEntry 3
Local port number
tcpConnRemAddress
TcpConnEntry 4
Remote IP address
tcpConnRemPort
TcpConnEntry 5
Remote port number
udpInDatagrams
(1)
udpLocAddress
(1)
Figure 4.37 UDP Group
udpNoPorts
(2)
udpInErrors
(3)
udp
(mib-2 7)
udpOutDatagrams
(4)
udpTable
(5)
udpEntry
(1)
udpLocalPort
(2)
Entity
OID
Description (brief)
udpInDatagrams
udp 1
Total number of datagrams delivered to the
users
udpNoPorts
udp 2
Total number of received datagrams for
which there is no application
udpInErrors
udp 3
Number of received datagrams with errors
udpOutDatagrams
udp 4
Total number of datagrams sent
udpTable
udp 5
UDP Listener table
udpEntry
udpTable 1
Information about a particular connection or
UDP listener
udpLocalAddress
udpEntry 1
Local IP address
udpLocalPort
udpEntry 2
Local UDP port
