Application Layer Protocol and Functionality

7/31/2019 Application Layer Protocol and Functionality

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Application Layer Protocol and

functionality


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WHAT IS LDAP

LDAP IS LIGHT WEIGHT

SUFFICIENT STRAIGHT FORWARD

EASY TO IMPLEMENT AS AGAINST X.500 DAPWHICH IS HEAVY WEIGHT


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LDAP

DIRECTORY BECAUSE DATA IS ORGANISED IN

THE FORM OF TREE MUCH LIKE UNIX FILE

SYSTEM

USES SIMPLIFIED SET OF ENCODING

RUNS DIRECTLY ABOVE TCP/IP

USES STRING TO REPRESENT DATA


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LDAP

LDAP SECURITY MODEL : DEFINES HOW

INFORMATION CAN BE PROTECTED FROM

UNAUTHORISED ACCESS


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LDAP

LDAP API

THERE ARE SEVERAL LDAP API

APPLICATION PROGRAMMING INTERFACE

OLDEST ONES WRITTEN IN C

NOW A DAYS LDAP API S ARE AVAILABLE IN

OTHER PROGRAMMING LANGUAGES LIKE

PERL JAVA


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HOW LDAP WORKS

LDAP DIRECTORY SERVICE IS BASED ON

CLIENT SERVER MODEL

LDAP IS A MESSAGE ORIENTED PROTOCOL

CLIENT CONSTRUCTS AN LDAP MESSAGE

CONTAINING A REQUEST AND SENDS IT TOTHE SERVER


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HOW LDAP WORKS

SERVER PROCESSES THE REQUEST AND

SENDS IT BACK TO THE CLIENT IN THE FORM

OF LDAP MESSAGE


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LDAP BACKENDS

THE BASIC DAEMON PROCESS THAT RUNS

ON THE LDAP SERVER CALLED SLAPD

COMES WITH THREE DIFFERENT BACKEND

DATABASES

WE ASSUME THAT IN OUR CASE WE USE

LDBM THE MOST USED ONE


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HOW LDAP WORKS

LDAP DATABASE WORKS BY ADDING A

COMPACT FOUR BYTE UNIQUE IDENTIFIER

INDEX FILES ARE MAINTAINED FOR

REFERRING TO DATA


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LDAP PROTOCOL OPERATION

INTERROGATION OPERATION : SEARCH

, COMPARE ADD DELETE OPERATOIN : ADD ,

DELETE , MODIFY , MODIFY DN

AUTHENTICATION AND CONTROLOPERATION : BIND ,

UNBIND , ABANDON


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LDAP INFORMATION MODEL

BASIC UNIT IS ENTRY ( A COLLECTION OF

INFORMATION ABOUT AN OBJECT )

AN ENTRY IS COMPOSED OF A SET OF

ATTRIIBUTES


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Definition of MIME

MIME, stand for Multi-purpose Internet mailExtensions, is a freely available specification thatoffers a way to interchange text in languages withdifferent character sets, and multimedia e-mailamong many different computer system that use

Internet mail standards.


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Introduction

MIME extends the format of Internet mail to allow non-US-ASCII textual messages, non-textual messages,multipart message bodies, and non-US-ASCIIinformation in message headers.

MIME provides Internet mail users with functionalitysimilar to that of MS-Mail for LAN-based internal mail.MS-Mail and MIME allow the attachment of files andother objects, as does MIME. Unfortunately,

Microsofts method of handling these attachments isundertaken through a proprietary format and MS-Maildoes not provide compliance with the MIME open

standard.


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What exactly is MIME?

In 1992, a new standard was defined by anInternet engineering task force working group inRFC1521 & 1522 called MIME.

MIME is an extension to the Internet mail standard,known as Simple Mail Transfer Protocol (SMTP)that allows mail messages containing differenttype of multimedia information to be sent acrossthe network this includes, but is not limited to,word-processor documents, spreadsheets,programs, graphics, audio, and motion picturefiles, as well as links that enable users to retrieveinformation from remote databases from within a

mail message.


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Cont

MIME is a specification for enhancing thecapabilities of standard Internet e-mail.

It offers a simple standardized way to representand encode a wide variety of media types oftransmission via Internet mail.

It is defines extensions to SMTP to supportbinary attachments of arbitrary format.

The designers of MIME have learned a lot fromthe old SMTP protocol and its mailers.

MIME is here to stay and it works.


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Cont

When using the MIME standard, messages cancontain the following types:

Text message in US-ASCII

Character set other than US-ASCII

Multiple objects in a single messages

Multimedia; Image, Audio, and Video messages

Multi-front messages

Messages of unlimited length

Binary files


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Cont

MIME is defined to be completely backwardscompatible, yet flexible and open toextensions. Therefore, it builds on the older

standard by defining additional fields for themail message header, that describes newcontent types, and a distinct organization ofthe message body.


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How MIME works?

The developers of MIME found a clever way towork around the limitation. It packages differentdata types into a 7-bit ASCII format. that way, all

e-mail, regardless of the data it contains, appearsas standard e-mail messages to the internetsSMTP servers. The beauty of the solution lies in

the fact that SMTP didnt have to change to

handle such data.


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Cont

Uses a new binary encoding scheme calledBASE 64

New SMTP headers describe the attached

document

User agents read the header to figure out howto interpret the message


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MIME Specific technical definition

New MIME headers

The Content-type headers

The Application-type headers

The Content-transfer-Encoding The Content-ID &Content Description

Multipart Message

Non-ASCII text in mail messages


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The Content-type Header

Content-type sub-type describes what formatthis part of the message is in

Text Image

Message AudioApplication Video

Multipart

The default type is simple ASCII text

MIME-Version : 1.0

Content-type:text/plain;charset=US-ascii


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The Content-type Applications Subtypes:

Postscript

Octet-Stream-Unidentified binarydata

Many other will be added


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The Content-transfer-Encoding

Base64 encoding algorithm is used to encodebinary data in 7bit ASCII data

Quoted-printable is for text-only messages

A few others

7bit No encoding Case insensitive

8bit No encoding

Binary No encodingX-token No encoding

Example


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Summary

MIME has been designed to avoid problemscaused by additional restrictions imposed bysome Internet mail transport mechanisms.

The Multipart and Message content types allowmixing and hierarchical structuring of objects ofdifferent types in a single message. Furthercontent types provide a mechanism for taggingmessages or body parts as audio, image, orother kinds of data.

Finally, a number of useful content types aredefined for general use by consenting useragents, notably Text/Richtext, Message/Partial,and Message/External-Body.


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POP

POP supports simple download-and-delete requirements foraccess to remote mailboxes (termed maildrop in the POPRFC's).

Although most POP clients have an option to leave mail onserver after download, e-mail clients using POP generally

connect, retrieve all messages, store them on the user's PC asnew messages, delete them from the server, and thendisconnect.

POP (POP1) is specified in RFC 918 (1984),

POP2 by RFC 937 (1985).

The original specification of POP3 is RFC 1081 (1988). Itscurrent specification is RFC 1939, updated with an extensionmechanism, RFC 2449 and an authentication mechanism inRFC 1734.
http://www.answers.com/topic/request-for-commentshttp://tools.ietf.org/html/rfc918http://tools.ietf.org/html/rfc937http://tools.ietf.org/html/rfc1939http://tools.ietf.org/html/rfc1081http://tools.ietf.org/html/rfc2449http://tools.ietf.org/html/rfc1939http://tools.ietf.org/html/rfc1734http://tools.ietf.org/html/rfc2449http://tools.ietf.org/html/rfc1734http://tools.ietf.org/html/rfc1734http://tools.ietf.org/html/rfc2449http://tools.ietf.org/html/rfc1939http://tools.ietf.org/html/rfc1081http://tools.ietf.org/html/rfc937http://tools.ietf.org/html/rfc918http://www.answers.com/topic/request-for-comments


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POP

Usually, mailboxes are kept on a dedicatedmachine.

Computer with mailboxes runs POP server.

User runs POP client on local computer. POP client can access and retrieve messages

from mailbox.

Requires authentication (password).

Local computer uses SMTP for outgoing mail.


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POP


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POP and Dialup Access

POP useful for dialup connection. Users computer not always connected.

Can download all mail at once and read off-line.

An alternative to POP:IMAP(Interactive MailAccess Protocol):

Does not copy email to users PC- email always

resides in the mail server. Useful when user uses several computers.


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POP3

Stands for Post Office Protocol Version 3

RFC in 1993

POP3 is intended to permit a workstation todynamically access a maildrop on a server

host in a useful fashion. Usually, this means

that the POP3 protocol is used to allow a

workstation to retrieve mail that the server isholding for it.


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POP3

Doesnt provide extensive mail operations on

the server

Normally mail is downloaded, then deleted

Deletion doesnt really occur until QUIT

Uses port 110


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Minimal POP3 Commands

USER nameusers name

PASS stringusers password

QUIT quits, and updates the mailbox

STAT status LIST [msg]lists the mail messages (#s only)

RETR msg retrieves a mail message

DELE msg deletes a message

NOOP No operation

RSET resets the mail to its original state


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RMON

What is RMON?

RMON is the common abbreviation for Remote Monitoring, a system defined by the IETF thatallows you to monitor the traffic of LANs or VLANs remotely.

RMON (Remote Network Monitoring) provides standard information that a networkadministrator can use to monitor, analyze, and troubleshoot a group of local area networks(LANs) from central location.

Remote Monitoring (RMON) is an extension to the SNMP MIB, and includes two versions RMON and RMON 2.

MIB - A Management Information Base (MIB) is a collection of information that is organizedhierarchically. MIBs are accessed using a network-management protocol such as SNMP. Theyare comprised of managed objects and are identified by object identifiers.


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Goals of RMON

RMON, primary goal is to provide information

relating to network errors and utilization.

RMON data is gathered as part of ten

different monitoring groups.


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RMON

Offline Operation:There are sometimes conditions when a management station willnot be in constant contact with its remote monitoring devices.Probes will perform diagnostics and to collect statisticscontinuously, even when communication with the managementstation may not be possible or efficient

Proactive Monitoring :Continuously run diagnostics and log network performance andnotify the management station of the failure and store historicalstatistical information about the failure.


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RMON

Problem Detection and Reporting :The monitor can be configured to recognize conditions, mostnotably error conditions, and to continuously check for them. Whenone of these conditions occurs, the event may be logged, andmanagement stations may be notified in a number of ways.

Value Added Data :Highlighting those hosts on the network that generate the mosttraffic or errors, the probe can give the management stationprecisely the information it needs to solve a class of problems.


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Version of RMON

RMON was originally developed to address the problem of managing LANsegments and remote sites from a Central Location.

There are two versions of RMON, RMON 1 & RMON 2:

RMON1-It defines 10 MIB groups for basic monitoring.

It allows network monitoring at MAC layer or belowRMON1 was only capable of providing information up to the MAC level,

RMON2-This is an extension of RMON 1 that focuses on higher layers of traffic above theMAC layerIt has an emphasis on IP traffic and application level trafficIt allows network management applications to monitor packets on all network

layers.RMON 2 is capable of monitoring traffic up to the application level.


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Working of RMON

Working of the RMONSetup:FDDI Backbone network with a local Ethernet LAN, two remote LANS, one is a token ring LAN andthe other an FDDI Lan.NMS is on the the local Ethernet LAN

MonitoringEthernet Local LAN is monitored by the Ethernet probe on the LAN.The FDDI backbone is monitored by an FDDI probe via the bridge and Ethernet LAN.

Token Rink is monitored by the token ring probeThe FDDI LAN is monitored by the built in probe on the router.Both the remote LANs communicate with the NMS via the routers, the WAN and the backbonenetwork,

WorkingRMON devices monitors the local network segment & does the necessary analyses and informs theNMS only when there are exceptions or NMS requests for some info.This reduces the traffic especially on the segment in which the NMS resides, as all the monitoringtraffic would otherwise converge there.

Alarm GroupSet thresholds on a variety of items affecting network performanceWhen the thresholds are crossed, events are reported.In general, the values of thresholds are determined according to past experience


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Advantages of RMON

It improves your efficiency -Using RMON probes allows you to remain at one workstation andcollect information from widely dispersed LAN segments or VLANs. This means that the timetaken to reach a problem site, set up equipment, and begin collecting information is largelyeliminated.

It allows you to manage your network in a more proactive manner- If they are configuredcorrectly, RMON probes deliver information before problems occur. This means that you can

take action before they affect users. It reduces the load on the network and the management workstation Traditional network

management involves a management workstation polling network devices at regular intervalsto gather statistics and identify problems or trends. As network sizes and traffic levels grow,this approach places a strain on the management workstation and also generates largeamounts of traffic. An RMON probe, however, autonomously looks at the network on behalfof the management workstation without affecting the characteristics and performance of thenetwork. The probe reports by exception, which means that it only informs the management

workstation when the network has entered an abnormal state. Increases Productivity for administrators.

Permits monitoring on a more frequent basis and hence faster fault diagnosis.

Needs no direct visibility by NMS; more reliable information


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Disadvantages of RMON

The amount of information it provides is insufficient for networkmanagers and administrators who need to solve complex problems,often at a distance.

The mechanism employed for data retrieval to a centralmanagement console are slow and very bandwidth inefficient.

RMON values are stored in 32 bit registers which limit the countvalue to 4,294,967,295. Although a seemingly large value, this isactually quite small. In a 100 Mbps fast Ethernet network running atjust 10% loading, the counters will be reset to zero after just onehour of acitivity.

Full RMON support in hardware typically requires dedicated RISC

processor technology and this is achievable in sub -$1,000 routers,hubs etc.

i l k i


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SNTP-Simple Network Time

Protocol Simple Network Time Protocol (SNTP) is a time-

maintenance application that you can use tosynchronize hardware in a network.

Simple Network Time Protocol (SNTP) is used to keep

device clocks synchronized. By using timestamps thatare kept synchronized, SNTP is useful for trackingprocesses and for interactions between systems.

i5/OS SNTP is based on Request for Comments (RFC)

2030. You can view RFC 2030 by searching for thenumber with the RFC index search engine located onthe RFC editor Web site.

SNTP Cli


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SNTP Client

When Simple Network Time Protocol (SNTP) is configured as a client,the i5/OS operating system retrieves a time value from an externaltime source. You can specify from which sources (up to three) toretrieve the time value. This external time value is compared to thesystem time.

If the system time value does not match the external time source, atime adjustment begins.

The system time is adjusted until the required time value is reached.You can configure the i5/OS operating system as the SNTP client to polla Network Time Protocol (NTP) or an SNTP server to find the time.

The SNTP client updates the system clock. Most applications use thesystem clock as their time source. By updating the system clock,applications reflect the synchronized time obtained from the timeserver.


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SNTP Server

When you configure the i5/OS operating system as an SNTP

server, your system acts as a time server for other devices.

Other SNTP clients check time by polling your SNTP server. If

a clients time values do not match the SNTP server time, a

time adjustment begins.

The clients system time is adjusted until the required time

value is reached. This is useful for maintaining time within a

network.


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Basic tasks that fall under this category are:

What is Network Management?

Fault Management

Dealing with problems and emergencies in the network (router

stops routing, server loses power, etc.)

Performance Management

How smoothly is the network running?

Can it handle the workload it currently has?

Configuration Management

Keeping track of device settings and how they function


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Network Management must be...

The management interface must be...

The management mechanism must be...

Standardized

Extendible

Portable

Inexpensive

Implemented as software only


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Functional Areas of NetworkManagement

Configuration Management- inventory, configuration, provisioning

Fault Management- reactive and proactive network fault management

Performance Management- # of packets dropped, timeouts, collisions, CRC errors

Security Management- SNMP doesnt provide much here

Accounting Management- cost management and chargeback assessment

Asset Management- statistics of equipment, facility, and administration personnel

Planning Management- analysis of trends to help justify a network upgrade orbandwidth increase

SNMP & N t k M t Hi t


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SNMP & Network Management History

1983- TCP/IP replaces ARPANET at U.S. Dept. of Defense, effective birth of Internet

First model for net management - HEMS - High-Level Entity Management System (RFCs1021,1022,1024,1076)

1987- ISO OSI proposes CMIP - Common Management Information Protocol, and CMOT(CMIP over TCP) for the actual network management protocol for use on the internet

Nov. 1987- SGMP - Simple Gateway Monitoring protocol (RFC 1028)

1989- Marshall T. Rose heads up SNMP working group to create a common network

management framework to be used by both SGMP and CMOTto allow for transition toCMOT

Aug. 1989- Internet-standard Network Management Framework defined (RFCs 1065,1066, 1067)

Apr. 1989- SNMP promoted to recommendedstatus as the de facto TCP/IP networkmanagement framework (RFC 1098)

June 1989- IAB committee decides to let SNMP and CMOT develop separately

May 1990- IAB promotes SNMP to a standard protocol with a recommended status(RFC 1157)

Mar. 1991 - format of MIBs and traps defined (RFCs 1212, 1215)

TCP/IP MIB definition revised to create SNMPv1 (RFC 1213)


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Versions

Two major versions SNMPv1, SNMPv2

SNMPv1 is the recommended standard

SNMPv2 has become split into:

SNMPv2u - SNMPv2 with user-based security

SNMPv2* - SNMPv2 with user-based security and additional features

SNMPv2c - SNMPv2 without security


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What is SNMP?

SNMP is a tool (protocol) that allows for remoteand local management of items on the networkincluding servers, workstations, routers, switches

and other managed devices. Comprised of agents and managers

Agent - process running on each managed node collecting information

about the device it is running on.

Manager - process running on a management workstation that requests

information about devices on the network.


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Advantages of using SNMP

Standardized

universally supported

extendible

portable

allows distributed management access

lightweight protocol


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Client Pull & Server Push

SNMP is a client pull model

SNMP is a server push model

The management system (client) pulls data from the agent (server).

The agent (server) pushes out a trap message to a (client) management

system


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Ports & UDP

SNMP uses User Datagram Protocol (UDP) as the transport mechanism for SNMP

messages

UDP Port 161 - SNMP Messages

UDP Port 162 - SNMP Trap Messages

Like FTP, SNMP uses two well-known ports to operate:

Ethernet

Frame IP Packet

UDP

Datagram

SNMP Message CRC


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SNMP network management is based on three parts:

The Three Parts of SNMP

Structure of Management Information (SMI)

Rules specifying the format used to define objects managed on

the network that the SNMP protocol accesses

Management Information Base (MIB)

A map of the hierarchical order of all managed objects and how

they are accessed

SNMP Protocol

Defines format of messages exchanged by management systemsand agents.

Specifies the Get, GetNext, Set, and Trap operations


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NodesItems in an SNMP Network are called nodes. There are different types of nodes.

Managed nodes

Management nodes

Nodes that are not manageable by SNMP

Typically runs an agent process that services requests from a management node

Typically a workstation running some network management & monitoring software

A node may not support SNMP, but may be manageable by SNMP through a proxy agentrunning on another machine

Nodes can be both managed nodes and a management node at the same time (typically thisis the case, since you want to be able to manage the workstation that your management application is running on.)


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Community Names

Community names are used to define where an SNMP message is destined for.

They mirror the same concept as a Windows NT or Unix domain.

Set up your agents to belong to certain communities.

Set up your management applications to monitor and receive traps from certain

community names.


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SNMP Agents

Two basic designs of agents

Extendible Agents

Monolithic Agents

not extendible

optimized for specific hardware platform and OS

this optimization results in less overhead (memory and system resources) and

quicker execution

Open, modular design allows for adaptations to new management

data and operational requirements


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Proxy & Gateway Agents

Proxy & Gateway Agents extend the capabilities of SNMP by allowing it to:

Manage a device that cannot support an SNMP agent

Manage a device that supports a non-SNMP management agent

Allow a non-SNMP management system to access an SNMP agent

Provide firewall-type security to other SNMP agents (UDP packet filtering)

Translate between different formats of SNMP messages (v1 and v2)

Consolidate multiple managed nodes into a single network address (also toprovide a single trap destination)


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Four Basic Operations

Get

GetNext

Set

Trap

Retrieves the value of a MIB variable stored on the agent machine

(integer, string, or address of another MIB variable)

Retrieves the next value of the next lexical MIB variable

Changes the value of a MIB variable

An unsolicited notification sent by an agent to a management application(typically a notification of something unexpected, like an error)

Traps


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TrapsTraps are unrequested event reports that are sent to a management system by an SNMP

agent process

When a trappable event occurs, a trap message is generated by the agent and is sent to a

trap destination (a specific, configured network address)

Many events can be configured to signal a trap, like a network cable fault, failing NIC or

Hard Drive, a General Protection Fault, or a power supply failure

Traps can also be throttled -- You can limit the number of traps sent per second from theagent

Traps have a priority associated with them -- Critical, Major, Minor, Warning, Marginal,

Informational, Normal, Unknown

Trap Receivers


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Trap ReceiversTraps are received by a management application.

Management applications can handle the trap in a few ways:

Poll the agent that sent the trap for more information about the event, and the

status of the rest of the machine.

Log the reception of the trap.

Completely ignore the trap.

Management applications can be set up to send off an e-mail, call a voice mail and leave

a message, or send an alpha-numeric page to the network administrators pager that says:

Your PDC just Blue-Screened at 03:46AM. Have a nice day. :)


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Languages of SNMP

Structure of Management Information (SMI)

Abstract Syntax Notation One (ASN.1)

Basic Encoding Rules (BER)

specifies the format used for defining managed objects that are

accessed via the SNMP protocol

used to define the format of SNMP messages and managed objects

(MIB modules) using an unambiguous data description format

used to encode the SNMP messages into a format suitable for

transmission across a network

S


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SMIv1Structure of Management Information

SMIv1 is described in RFCs 1155, 1212, 1215

These RFCs describe:

How MIB modules are defined with CCITT X.208 ASN.1 data description language

The subset of the ASN.1 language that is used in MIBs

The addition of the APPLICATION data type to ASN.1, specifically for use with

SNMP MIBs

All ASN.1 constructs are serialized using the CCITT X.209 BER for transmission

across the wire

definition of the high-level structure of the Internet branch

(iso(1).org(3).dod(6).internet(1)) of the MIB naming tree

the definition and description of an SNMP managed object


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SMIv2Structure of Management Information

SMIv2 is described in RFCs 1442, 1443, 1444

These RFCs describe:

SMIv2 is a backward compatible update to SMIv1

The only exception is the Counter64 type defined by SMIv2

Counter64 cannot be created in SMIv2

RFC 2089 defines how bilingual (SMIv1 & SMIv2) agents handle the Counter64data type

IETF requires that new and revised RFCs specify MIB modules using SMIv2


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ASN.1Abstract Syntax Notation One

ASN.1 is nothing more than a language definition. It is similar to C/C++ and

other programming languages.

Syntax examples:

-- two dashes is a comment -- The C equivalent is written in the comment

MostSevereAlarm ::= INTEGER -- typedef MostSevereAlarm int;

circuitAlarms MostSevereAlarm ::= 3 -- MostSevereAlarm circuitAlarms = 3;

MostSevereAlarm ::= INTEGER (1..5) -- specify a valid range

ErrorCounts ::= SEQUENCE {

circuitID OCTET STRING,

erroredSeconds INTEGER,

unavailableSeconds INTEGER

} -- data structures are defined using the SEQUENCE keyword


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BER

Basic Encoding Rules

The relationship between ASN.1 and BER parallels that of source code and machine

code.

CCITT X.209 specifies the Basic Encoding Rules

All SNMP messages are converted / serialized from ASN.1 notation into smaller,

binary data (BER)

SNMP D T


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INTEGER -- signed 32-bit integer

OCTET STRING

OBJECT IDENTIFIER (OID)

NULL-- not actually data type, but data value

IpAddress -- OCTET STRING of size 4, in network byte order (B.E.)

Counter -- unsigned 32-bit integer (rolls over)

Gauge -- unsigned 32-bit integer (will top out and stay there)

TimeTicks -- unsigned 32-bit integer (rolls over after 497 days)Opaque -- used to create new data types not in SNMPv1

DateAndTime, DisplayString, MacAddress, PhysAddress, TimeInterval, TimeStamp,

TruthValue, VariablePointer -- textual conventions used as types

SNMP Data Types

Yellow items defined by

ASN.1

Orange items defined by

RFC 1155


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Managed Objects & MIBs

Always defined and referenced within the context of a MIB

A typical MIB variable definition:

sysContact OBJECT-TYPE -- OBJECT-TYPE is a macro

SYNTAX DisplayString (SIZE (0..255))

ACCESS read-write -- or read-write, write-only, not-accessible

STATUS mandatory -- or optional, deprecated, obsolete

DESCRIPTION

Chris Francois

[email protected]

(360)650-0000

::= { system 4 }


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Basic Message Format

Message Length

Message Version

Community String

PDU Header

PDU Body

Message Preamble

SNMP Protocol DataUnit

Message Length

Message VersionSNMP

SNMP Message Formats


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Message Length

Message Version

Community String

PDU Type

PDU Length

Request ID

Error Status

Error Index

Length of Variable Bindings

Length of First Binding

Additional Variable Bindings

OID of First Binding

Type of First Binding

Value of First Binding

Length of Second Binding

OID of Second Binding

Type of Second Binding

Value of Second Binding

Message Version

Community String

PDU Type

PDU Length

Enterprises MIB OID

Agent IP Address

Standard Trap Type

Length of Variable Bindings

Length of First Binding

Additional Variable Bindings

OID of First Binding

Type of First Binding

Value of First Binding

Length of Second Binding

OID of Second Binding

Type of Second Binding

Value of Second Binding

Specific Trap Type

Time Stamp

PDU

Body

SNMP

Message

Preamble

PDU

Header

Commercial SNMP Applications


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Commercial SNMP ApplicationsHere are some of the various SNMP Management products available today:

http://www.hp.com/go/openview/ HP OpenView

http://www.tivoli.com/ IBM NetView

http://www.novell.com/products/managewise/ Novell ManageWise

http://www.sun.com/solstice/ Sun MicroSystems Solstice

http://www.microsoft.com/smsmgmt/ Microsoft SMS Server

http://www.compaq.com/products/servers/management/ Compaq Insight Manger

http://www.redpt.com/ SnmpQL - ODBC Compliant

http://www.empiretech.com/ Empire Technologies

ftp://ftp.cinco.com/users/cinco/demo/ Cinco Networks NetXray

http://www.netinst.com/html/snmp.html SNMP Collector (Win9X/NT)

http://www.netinst.com/html/Observer.html Observer

http://www.gordian.com/products_technologies/snmp.html Gordians SNMP Agent

http://www.castlerock.com/ Castle Rock Computing

http://www.adventnet.com/ Advent Network Management

http://www.smplsft.com/ SimpleAgent, SimpleTester

SNMP & Windows NT 5 0


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SNMP & Windows NT 5.0Proposed features of the Windows NT5 SNMP Service

Full bilingual support for SNMPv1 and SNMPv2c

ability to map SNMPv2c requests to SNMPv1 for processing by

extension agents

better synchronization of MIB variables

a new extension agent framework(backward compatible with originalframework, but with MS add-ons)

code-generator for creation of extension agents

MIB-II, LAN Manager 2, IP Forwarding MIB (RFC 1354), and Host Resources MIB

(RFC 1514) extension agents included

All MIB modules included with SNMP install

SMS 2.0 also has a Symantec PCAnywhere type of application integrated into it,

allowing remote-but-local management as well

RFC Description Published Current Status


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SNMP

RFCs

RFC Description Published Current Status1065 SMIv1 Aug-88 Obsoleted by 1155

1066 SNMPv1 MIB Aug-88 Obsoleted by 1156

1067 SNMPv1 Aug-88 Obsoleted by 1098

1098 SNMPv1 Apr-89 Obsoleted by 1157

1155 SMIv1 May-90 Standard

1156 SNMPv1 MIB May-90 Historic

1157 SNMPv1 May-90 Standard1158 SNMPv1 MIB-II May-90 Obsoleted by 1213

1212 SNMPv1 MIB definitions Mar-91 Standard

1213 SNMPv1 MIB-II Mar-91 Standard

1215 SNMPv1 traps Mar-91 Informational

1351 Secure SNMP administrative model Jul-92 Proposed Standard

1352 Secure SNMP managed objects Jul-92 Proposed Standard

1353 Secure SNMP security protocols Jul-92 Proposed Standard

1441 Introduction to SNMPv2 Apr-93 Proposed Standard

1442 SMIv2 Apr-93 Obsoleted by 1902

1443 Textual conventions for SNMPv2 Apr-93 Obsoleted by 19031444 Conformance statements for SNMPv2 Apr-93 Obsoleted by 1904

1445 SNMPv2 administrative model Apr-93 Historic

1446 SNMPv2 security protocols Apr-93 Historic

1447 SNMPv2 party MIB Apr-93 Historic

1448 SNMPv2 protocol operations Apr-93 Obsoleted by 1905

1449 SNMPv2 transport mapping Apr-93 Obsoleted by 1906

1450 SNMPv2 MIB Apr-93 Obsoleted by 1907

1451 Manger-to-manger MIB Apr-93 Historic

1452 Coexistence of SNMPv1 and SNMPv2 Apr-93 Obsoleted by 1908

1901 Community-Based SNMPv2 Jan-96 Experimental1902 SMIv2 Jan-96 Draft Standard

1903 Textual conventions for SNMPv2 Jan-96 Draft Standard

1904 Conformance statements for SNMPv2 Jan-96 Draft Standard

1905 Protocol operations for SNMPv2 Jan-96 Draft Standard

1906 Transport mapping for SNMPv2 Jan-96 Draft Standard

1907 SNMPv2 MIB Jan-96 Draft Standard

1908 Coexistence of SNMPv1 and SNMPv2 Jan-96 Draft Standard

1909 Administrat ive infrastructure for SNMPv2 Feb-96 Experimental

1910 User-based security for SNMPv2 Feb-96 Experimental


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Light Weight Presentation Protocol

Lightweight Presentation Protocol (LPP) describes an approachfor providing "stream-lined" support of OSI application services ontop of TCP/IP-based network for some constrained environments.

LPP was initially derived from a requirement to run the ISO

Common Management Information Protocol (CMIP) in TCP/IP-based network.

LPP is designed for a particular class of OSI applications, namelythose entities whose application context contains only anAssociation Control Service Element (ACSE) and a RemoteOperations Service Element (ROSE). In addition, a DirectoryServices Element (DSE) is assumed for use by the application-entity, but only in a very limited sense. LPP is not applicable toentities whose application context is more extensive (e.g.,contains a Reliable Transfer Service Element).

If one wants to implement ISO applications in a TCP/IP based network without


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constrains, the ITOT mechanisms (specified in RFC 2126) should be used.

Protocol Structure - LPP: Lightweight Presentation Protocol The

service provider is in one of the following states:IDLE, WAIT1, WAIT2, DATA, WAIT3, or WAIT4

The possible events are:PS-user P-CONNECT.REQUESTP-CONNECT.RESPONSEP-RELEASE.REQUEST

P-RELEASE.RESPONSEP-DATA.REQUESTP-U-ABORT.REQUESTnetwork TCP closed or errored(*)receive ConnectRequest PDUreceive ConnectResponse PDU

receive ReleaseRequest PDUreceive ReleaseResponse PDUreceive UserData(*) or CL-UserData(**) (*) tcp-based service only(**) udp-based service only

PDUi i iti t d Ab t PDU


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receive user-initiated Abort PDUreceive provider-initiated Abort PDUtimer expires(**)

The possible actions are:

PS-user P-CONNECT.INDICATIONP-CONNECT.CONFIRMATIONP-RELEASE.INDICATIONP-RELEASE.CONFIRMATIONP-DATA.INDICATIONP-U-ABORT.INDICATION

P-P-ABORT.INDICATIONnetwork open TCP(*)close TCP(*)send ConnectRequest PDUsend ConnectResponse PDUsend ReleaseRequest PDUsend ReleaseResponse PDUsend UserData(*) or CL-UserData(**) PDUsend user-initiated Abort PDUsend provider-initiated Abort PDUset timer(**)

Application Layer Protocol and Functionality

Documents

Transcript of Application Layer Protocol and Functionality