name resolution

Name Resolution

Presented Presented By By

Tom BattagliaTom BattagliaThomas Text

4 Section presentation

Section 1 - Resolution Methods DefinedSection 1 - Resolution Methods Defined

Section 2 - Microsoft Name ResolutionSection 2 - Microsoft Name Resolution

Section 3 - The OSI ModelSection 3 - The OSI Model

Section 4 - TroubleshootingSection 4 - Troubleshooting

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Section 1 of 4 Section 1 of 4 Resolution Methods Defined Resolution Methods Defined

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Resolution Methods

What is Name resolutionWhat is Name resolution Computers communicate using IP’sComputers communicate using IP’s

People communicate using computer namesPeople communicate using computer names

Name resolution is a result of a client query to Name resolution is a result of a client query to get an IP address for a computer nameget an IP address for a computer name

““Name Server” - The server that can hand out Name Server” - The server that can hand out an IP after a query for one is madean IP after a query for one is made

NOTE: If a client uses an IP to communicate the NOTE: If a client uses an IP to communicate the Name Server is not necessaryName Server is not necessary

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Resolution Methods

Types of Resolution MethodsTypes of Resolution Methods Broadcast for NetBIOS NameBroadcast for NetBIOS Name WINSWINS - Windows Internet Name Server - Windows Internet Name Server DNSDNS - Domain Name Server - Domain Name Server DDNSDDNS - Dynamic Domain Name Server - Dynamic Domain Name Server

Node Type Resolution of Microsoft clientsNode Type Resolution of Microsoft clients B-node / P-node / M-node / H-nodeB-node / P-node / M-node / H-node LMHOST / HOSTLMHOST / HOST

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Broadcast for Broadcast for NetBIOS "Short" NameNetBIOS "Short" Name

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Resolution Methods Defined

Broadcast - CharacteristicsBroadcast - Characteristics Routers do not forward Broadcast requests off Routers do not forward Broadcast requests off

of the subnetof the subnet

Only NetBIOS "Short"names can be resolved Only NetBIOS "Short"names can be resolved on the local subneton the local subnet

Every Client on the subnet processes Every Client on the subnet processes Broadcast packetsBroadcast packets

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Windows Internet Name Service Windows Internet Name Service (WINS)(WINS)

Note: Microsoft Windows Clients Only

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Resolution Methods DefinedWINS

WINS - WINS - Server Characteristics Characteristics

Resolves NetBIOS "Short" Names onlyResolves NetBIOS "Short" Names only• i.e. Batman01i.e. Batman01

Client updates dynamic database on WINS Client updates dynamic database on WINS server during startup or Nbtstat -RR server during startup or Nbtstat -RR

Admin can add static entries to WINSAdmin can add static entries to WINS

ONLY Services are registered in WINSONLY Services are registered in WINS

WINS Servers exchange entries by being WINS Servers exchange entries by being "Push/Pull" partners"Push/Pull" partners

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WINS - WINS - Client Characteristics Characteristics

* Client DOES NOT use secondary unless * Client DOES NOT use secondary unless primary WINS server is downprimary WINS server is down

To resolve a name to an IP the client must be To resolve a name to an IP the client must be using a WINS server that the destination using a WINS server that the destination

server registered withserver registered with

ORThe clients WINS server is a "Push/Pull" The clients WINS server is a "Push/Pull"

partner of the destinations WINS serverpartner of the destinations WINS server

* NT4 Only. W2K will use Secondary after a delay.* NT4 Only. W2K will use Secondary after a delay.Thomas Text


WINS – Server LocationsWINS – Server Locations

AUSWINSRR201 143.166.233.252

W2K

AUSWINSPS201 143.166.140.96

"NEW W2K"

BNAWINSEG101 163.244.252.252

W2K

BNADHCPCORP01 163.244.252.244

W2K

AUSWINSBT101 143.166.33.148

W2K

AUSWINSBT102 143.166.98.24

"PoleStar1

PENMDSWINS01 163.244.112.253

W2K

PENWINSD1O10 163.244.112.26

W2K

Japan

TK-BDC1 163.244.85.168

NT4

JPWINSDC101 163.244.85.166

W2K

IEBRYWINS01 163.244.76.31

NT4

PENWINSD101 163.244.101.26

W2K

PENWINSD102 163.244.101.27

W2K

EMEA

IELIMWINS01 163.244.4.32

NT4

EUROPEWINSNT2 163.244.79.191

NT4

CN-WINS1 163.244.235.26

NT4

WINS Servers

APCC2

APCC1

CHINA

AUSTIN

NASHVILLE

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WINS – MMC ExampleWINS – MMC Example

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WINS Entry TypeWINS Entry Type Service Registered Service Registered [00h] [00h] Computer NameComputer Name Workstation ServiceWorkstation Service

[03h] [03h] Computer NameComputer Name Messenger Service for ComputerMessenger Service for Computer

[20h] [20h] Computer NameComputer Name File Server ServiceFile Server Service

[BEh] [BEh] Computer NameComputer Name Network Monitoring Agent ServiceNetwork Monitoring Agent Service

[03h] [03h] User NameUser Name Messenger Service for the logged on userMessenger Service for the logged on user

[1Bh] [1Bh] Domain NameDomain Name Domain Master Browser Service – Domain Master Browser Service – PDCPDC

[1Dh] [1Dh] Domain NameDomain Name Subnet Master Browser ServiceSubnet Master Browser Service

WINS – WINS – Unique Type Examples Type Examples

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WINS Entry TypeWINS Entry Type Service Registered Service Registered [00h] Domain Name[00h] Domain Name Workstation Service Receives Workstation Service Receives

Browser Browser Broadcasts Broadcasts

[1Ch] Domain Name[1Ch] Domain Name Domain ControllersDomain Controllers 1 PDC1 PDC

24 BDCs24 BDCs

[1Eh] Domain Name[1Eh] Domain Name Used by Browsers for ElectionsUsed by Browsers for Elections

[01h] --_MSBROWSE_[01h] --_MSBROWSE_ Registered by Subnet Master BrowserRegistered by Subnet Master Browser

Returned to clients after QueryReturned to clients after Query

WINS – WINS – Group Type Examples Type Examples

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Domain Name Service Domain Name Service (DNS)(DNS)

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Resolution Methods DefinedDNS

DNS - DNS - Server Characteristics Characteristics Resolves Fully Qualified Domain Names Resolves Fully Qualified Domain Names

"FQDN""FQDN"• i.e. Batman01.us.dell.com.i.e. Batman01.us.dell.com.

Integrated Microsoft and UNIX ServersIntegrated Microsoft and UNIX Servers

AllAll Registrations are Statically Entered Registrations are Statically Entered

Provides Forward Lookup - Name to IPProvides Forward Lookup - Name to IP

Provides Reverse Lookup - IP to NameProvides Reverse Lookup - IP to Name

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DNS - DNS - Client Characteristics Characteristics

The Client uses Domain Suffixes to Lookup The Client uses Domain Suffixes to Lookup NamesNames

• i.e. "us.dell.com"i.e. "us.dell.com"• i.e. "dell.com"i.e. "dell.com"

Client WILL use Secondary if Name can not Client WILL use Secondary if Name can not be Found on Primary DNS Serverbe Found on Primary DNS Server

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Resolution Methods Defined DNS

DNS – Domain SuffixesDNS – Domain Suffixes

dell.com Root Domain

us.dell.com Child Domainus.dell.com AustinN/A Brazilca.dell.com CanadaN/A ChileN/A Columbiamx.dell.com MexicoN/A NashvilleN/A San Jose

my.dell.com APCC

Primary DNS Suffix NT4 Legacy

Austin AreaNON W2K

us.dell.comdell.comaus.amer.dell.comamer.dell.combna.amer.dell.comsjc.amer.dell.com

NT4 Client / Server

Setup

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DNS – DNS – Forward Lookup MMC Example MMC Example

Host Names

IP Address

IP Alias

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DNS – DNS – Forward Lookup Unix Example Unix Example

Host Names

IP Address

IP AliasThomas Text


DNS – DNS – Reverse lookup MMC Example MMC Example

IP - First Octet

Host Names

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DNS – DNS – Reverse lookup Unix Example Unix Example

Filename

IP - First Octet

Host Names

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Dynamic Domain Name Dynamic Domain Name ServiceService(DDNS)(DDNS)

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Resolution Methods DefinedDDNS

DDNS - DDNS - Server Characteristics Characteristics Resolves Fully Qualified Domain Names Resolves Fully Qualified Domain Names

"FQDN""FQDN"• i.e. Batman01.aus.amer.dell.com.i.e. Batman01.aus.amer.dell.com.

ONLY Microsoft W2K serversONLY Microsoft W2K servers

SomeSome Registrations are Statically Entered Registrations are Statically Entered

Provides Forward Lookup - Name to IPProvides Forward Lookup - Name to IP

Provides Reverse Lookup - IP to NameProvides Reverse Lookup - IP to Name

Proxy Lookup to the WINS ServerProxy Lookup to the WINS ServerThomas Text


DDNS - DDNS - Client Characteristics Characteristics

The Client uses Domain Suffixes to Lookup The Client uses Domain Suffixes to Lookup NamesNames

• i.e. "aus.amer.dell.com"i.e. "aus.amer.dell.com"• i.e. "amer.dell.com"i.e. "amer.dell.com"

Client WILL use Secondary if Name can not Client WILL use Secondary if Name can not be Found on Primary DNS Serverbe Found on Primary DNS Server

Registrations are Dynamically Entered when Registrations are Dynamically Entered when the W2K client uses a DDNS serverthe W2K client uses a DDNS server

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DDNS – Domain SuffixesDDNS – Domain Suffixes

dell.com Root Domainamer.dell.com Child Domain

aus.amer.dell.com Austinpoa.amer.dell.com Brazilyyz.amer.dell.com Canadabog.amer.dell.com Chilesgl.amer.dell.com Columbiamex.amer.dell.com Mexicobna.amer.dell.com Nashvillesjc.amer.dell.com San Jose

mfg.apcc.my.dell.com APCC

mds.my.dell.com APCC2

Primary DNS Suffix W2K

Austin Area

W2Kaus.amer.dell.comus.dell.comamer.dell.comdell.combna.amer.dell.comsjc.amer.dell.com

W2K Client / Server

Setup

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DDNS – DDNS – Forward Lookup MMC ExampleMMC Example

IP Address

Host NamesThomas Text


DDNS – DDNS – Reverse lookup MMC Example MMC Example

Not currently implemented at Dell on the W2K Not currently implemented at Dell on the W2K DDNS platformDDNS platform

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Section 2 of 4 Section 2 of 4 Microsoft Name Resolution Microsoft Name Resolution

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Microsoft Name Resolution

Part 1 - Resolution MethodsPart 1 - Resolution Methods B-node / P-node / M-node / H-nodeB-node / P-node / M-node / H-node LMHOST FileLMHOST File HOST FileHOST File

Part 2 - Combined Resolution MethodsPart 2 - Combined Resolution Methods NetBIOSNetBIOS DNSDNS

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Part 1 Part 1 Resolution MethodsResolution Methods

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B-Node - CharacteristicsB-Node - Characteristics Uses Broadcast NetBIOS Name Queries for Uses Broadcast NetBIOS Name Queries for

Name Registration and ResolutionName Registration and Resolution

B-Node Limitations:B-Node Limitations:

(1) Broadcasts Disturb every node on the (1) Broadcasts Disturb every node on the NetworkNetwork

(2) Routers Typically do not Forward (2) Routers Typically do not Forward Broadcasts, so only NetBIOS Names on Broadcasts, so only NetBIOS Names on the Local Network can be Resolvedthe Local Network can be Resolved

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P-Node - CharacteristicsP-Node - Characteristics Uses NetBIOS Name Server (NBNS)Uses NetBIOS Name Server (NBNS)

- Typically a WINS Server- Typically a WINS Server

P-Node Limitations:P-Node Limitations:

(1) If the Server is not Registered with (1) If the Server is not Registered with WINS the Client can not Resolve itWINS the Client can not Resolve it

(2) If the NBNS is "Down" the Client May (2) If the NBNS is "Down" the Client May not Resolve or will use the Secondary with not Resolve or will use the Secondary with Degraded ResultsDegraded Results

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M-Node - CharacteristicsM-Node - Characteristics Uses B-Node FirstUses B-Node First

Uses P-Node if B-Node does not ResolveUses P-Node if B-Node does not Resolve

M-Node Limitations:M-Node Limitations:

(1) Broadcasts Disturb Every Node on the (1) Broadcasts Disturb Every Node on the NetworkNetwork

(2) If the NBNS is "Down" the Client May (2) If the NBNS is "Down" the Client May not Resolve or will use the Secondary with not Resolve or will use the Secondary with Degraded ResultsDegraded Results

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H-Node - CharacteristicsH-Node - Characteristics Uses P-Node FirstUses P-Node First

Uses B-Node if B-Node does not ResolveUses B-Node if B-Node does not Resolve

H-Node Advantages:H-Node Advantages:

(1) It Does Not Use Broadcasts First(1) It Does Not Use Broadcasts First

(2) It Will Resolve Faster Using WINS and (2) It Will Resolve Faster Using WINS and cut down on Network Trafficcut down on Network Traffic

NOTE: This is the method Microsoft uses for all NOTE: This is the method Microsoft uses for all their Windows platformstheir Windows platforms

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LMHOST File - CharacteristicsLMHOST File - Characteristics Used to resolve Used to resolve NetBIOS "Short" NamesNetBIOS "Short" Names

Can have Entries Cached from fileCan have Entries Cached from file

Located in Located in [%systemroot%\system32\drivers\etc][%systemroot%\system32\drivers\etc]

LMHOST File Limitations:LMHOST File Limitations:

(1) Can hold only 128 entries(1) Can hold only 128 entries

(2) If a Name Changes all LMHOST Files (2) If a Name Changes all LMHOST Files Need to be UpdatedNeed to be Updated

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LMHOST File Example Example

LMHOST File - No Extension

LMHOST Sample File

Examples


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HOST File - CharacteristicsHOST File - Characteristics Used to resolve Used to resolve FQDN NamesFQDN Names

Can have Entries Cached from fileCan have Entries Cached from file

Located in Located in [%systemroot%\system32\drivers\etc][%systemroot%\system32\drivers\etc]

HOST File Limitations:HOST File Limitations:

(1) If a Name Changes all HOST Files Need (1) If a Name Changes all HOST Files Need to be Updatedto be Updated

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HOST File Example Example

HOST File - No Extension

Examples


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Part 2Part 2Combined Resolution MethodsCombined Resolution Methods

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All Microsoft Platforms - NetBIOSAll Microsoft Platforms - NetBIOS

Uses B-Node if no WINS Server SpecifiedUses B-Node if no WINS Server Specified

Uses H-Node Resolution if a WINS Server is Uses H-Node Resolution if a WINS Server is SpecifiedSpecified

If System Fails to Register with WINS it will If System Fails to Register with WINS it will Result in B-Node until it can Contact the Result in B-Node until it can Contact the WINS ServerWINS Server

Some Commands - Net View and NbtstatSome Commands - Net View and Nbtstat

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NetBIOS NetBIOS ResolutionResolution

H-NodeH-NodeLMHOST

Cache

WINS

Broadcast

LMHOSTFile

If Configured for "DNS for WINS

Resolution (NT4)"

HOSTFile

DNS Server

M-NodeM-NodeLMHOST

Cache

Broadcast

WINS

LMHOSTFile

If Configured for "DNS for WINS

Resolution (NT4)"

HOSTFile

DNS Server

P-NodeP-NodeLMHOST

Cache

WINS

LMHOSTFile

M-NodeM-NodeLMHOST

Cache

Broadcast

LMHOSTFile


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An example of name resolution would be like An example of name resolution would be like calling information to get the # - (IP Address)calling information to get the # - (IP Address) Try to remember the #Try to remember the # Call information to get a # for a nameCall information to get a # for a name

The operator can put your call throughThe operator can put your call through If the # is unlisted you might need to go in If the # is unlisted you might need to go in

your front yard and call their nameyour front yard and call their name Check the Counter for Pieces of PaperCheck the Counter for Pieces of Paper You might check your personal phone listYou might check your personal phone list Look it up in the phone book (FQDN)Look it up in the phone book (FQDN) Give up and go shoppingGive up and go shopping


H-NodeH-Node

Cache

WINS

Broadcast

LMHOST File

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DNS Server

Time OutThomas Text


All Microsoft Platforms - DNS / DDNSAll Microsoft Platforms - DNS / DDNS Client will look on Server and Query Using Client will look on Server and Query Using

the Domain Suffixesthe Domain Suffixes Some Commands - Ping, Ftp, and TelnetSome Commands - Ping, Ftp, and Telnet

DNS Server

Suffix Search Order

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Microsoft Reference ArticlesMicrosoft Reference Articles Q105997 - Differences Between the HOSTS and LMHOSTS Files in Windows NTQ105997 - Differences Between the HOSTS and LMHOSTS Files in Windows NT

Q119493 - NetBIOS over TCP-IP Name Resolution and WINSQ119493 - NetBIOS over TCP-IP Name Resolution and WINS

Q120642 - TCP-IP & NBT Configuration Parameters for Windows NT and Q120642 - TCP-IP & NBT Configuration Parameters for Windows NT and Windows 2000Windows 2000

Q142042 - Description of TCP-IP Node-Type Settings in Windows 95-98Q142042 - Description of TCP-IP Node-Type Settings in Windows 95-98

Q142309 - NetBIOS Name Resolution Using DNS and the HOSTS FileQ142309 - NetBIOS Name Resolution Using DNS and the HOSTS File

Q158474 - Windows TCP-IP Registry EntriesQ158474 - Windows TCP-IP Registry Entries

Q160177 - Default Node Type for Microsoft ClientsQ160177 - Default Node Type for Microsoft Clients

Q167640 - Automatically Changing the Node Type of a Windows NT WorkstationQ167640 - Automatically Changing the Node Type of a Windows NT Workstation

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Section 3 of 4 Section 3 of 4 The OSI ModelThe OSI Model

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Open Systems Interconnection (OSI) Model

OSI CharacteristicsOSI Characteristics Describes how information from a software application in Describes how information from a software application in

one computer moves through a network medium to a one computer moves through a network medium to a software application in another computer software application in another computer

Developed by the International Organization for Developed by the International Organization for Standardization (ISO) in 1984 Standardization (ISO) in 1984

Each layer being implemented independently enables the Each layer being implemented independently enables the solutions offered by one layer to be updated without solutions offered by one layer to be updated without adversely affecting the other layers adversely affecting the other layers

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OSI CharacteristicsOSI Characteristics Data Encapsulation and Decapsulation occurs as each Data Encapsulation and Decapsulation occurs as each

layer passes data up and down the stacklayer passes data up and down the stack

Layered approach for ease of Learning, Modular Layered approach for ease of Learning, Modular Engineering, Interoperability and Eases Standards Engineering, Interoperability and Eases Standards Development Development

Ethernet = FramesEthernet = Frames

TCP/IP = PacketsTCP/IP = PacketsThomas Text


Layer 7 — Application layer Layer 7 — Application layer Layer 6 — Presentation layer Layer 6 — Presentation layer Layer 5 — Session layer Layer 5 — Session layer Layer 4 — Transport layer Layer 4 — Transport layer Layer 3 — Network layer Layer 3 — Network layer Layer 2 — Data Link layer Layer 2 — Data Link layer Layer 1 — Physical layerLayer 1 — Physical layer

Implemented with software

Implemented with Software& Hardware

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ApplicationApplication PresentationPresentation SessionSession TransportTransport NetworkNetwork Data LinkData Link PhysicalPhysical

ApplicationApplication

TransportTransport InternetInternet InterfaceInterface

"FYI" OSI Compared to TCP/IP Stack"FYI" OSI Compared to TCP/IP Stack

OSI 7 LayersOSI 7 Layers TCP/IP 4 TCP/IP 4 LayersLayers

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Each layer communicates with three other OSI layers: Each layer communicates with three other OSI layers: 1.1. The layer directly above it, The layer directly above it, 2.2. The layer directly below itThe layer directly below it3.3. Its peer layer in other networked deviceIts peer layer in other networked device

Peer-to-Peer Communication

Protocol Data Units (PDU)

Lower Layer"Service Provider"

Upper Layer"Service User"

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Application Application Layer 6 Layer 5 Layer 4 Layer 3 Layer 2 Layer 1

Interface to Application Interface to User UDP Application examples

DHCP BOOTP TFTP

TCP Application examples HTTP FTP TELNET

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"Translator" Encryption Decryption Compression Decompression Architecture Independent data

transfer format. i.e. MPEG Gif Jpeg

Layer 7 PresentationPresentation Layer 5 Layer 4 Layer 3 Layer 2 Layer 1

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"Coordinator" Manage User Sessions

Establish Connection Manage Connection Terminate Connection

Report upper layer errors Protocols

AppleTalk Session Control Protocol DECnet Phase 5

Layer 7 Layer 6 SessionSession Layer 4 Layer 3 Layer 2 Layer 1

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"Segmenter" Reliable Packet Delivery Flow Control Multiplexing Error Checking Protocols Used

TCP UDP SPX NetBEUI

Layer 7 Layer 6 Layer 5 TransportTransport Layer 3 Layer 2 Layer 1

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Layer 7 Layer 6 Layer 5 Layer 4 NetworkNetwork Layer 2 Layer 1

"Packet" (Data gram) Logical Addressing Path Determination (Routing) Connectionless Best-Effort-Delivery Address Res. Protocol -ARP

IP to MAC Routed Protocols

IP / IPX / ICMP Routing Protocols

OSPF / RIP / BGPThomas Text


Layer 7 Layer 6 Layer 5 Layer 4 Layer 3 Data LinkData Link Layer 1

"Frame""Frame" Switches Operate HereSwitches Operate Here All devices talk MACAll devices talk MAC Header Contains MAC AddressHeader Contains MAC Address Error NotificationError Notification Network Topology DefinedNetwork Topology Defined Flow ControlFlow Control

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Data Link Layer Sub layersData Link Layer Sub layers Logical Link Control - LLCLogical Link Control - LLC

802.2802.2 Connectionless & Connectionless &

Connection OrientedConnection Oriented Media Access Control - MACMedia Access Control - MAC

Manage protocol Manage protocol access to the physical access to the physical layerlayer

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Layer 7 Layer 6 Layer 5 Layer 4 Layer 3 Layer 2 PhysicalPhysical

"Link" Changes data to electrical

impulses Transmits "Bits" onto the Wire Removes "Bits" off the Wire Physical error checking Does not add or take away

from the Frame Concerned with Physical

protocol and not Data Protocol

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Layer 7 Layer 6 Layer 5 Layer 4 Layer 3 Layer 2 PhysicalPhysical

Maintains the Physical Link Defines the physical medium

Voltage levels & timings

Data Rates Transmission

Distance Connectors Cables

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Section 4 of 4 Section 4 of 4 Troubleshooting Troubleshooting

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Troubleshooting

Part 1 - Basic Network TroubleshootingPart 1 - Basic Network Troubleshooting

Part 2 - NetBIOS TroubleshootingPart 2 - NetBIOS Troubleshooting Broadcast / WINS / LMHOST FileBroadcast / WINS / LMHOST File

Part 3 - FQDN TroubleshootingPart 3 - FQDN Troubleshooting DNS / DDNS / Host FileDNS / DDNS / Host File

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Part 1 Part 1 Basic Network TroubleshootingBasic Network Troubleshooting

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Client Considerations Considerations ONLY GATHER FACTS……….ONLY GATHER FACTS………...

• Don't trust the end user to evaluate.Don't trust the end user to evaluate.

Is it "Slow" or "Not Working"?Is it "Slow" or "Not Working"?• They Say "It's Dead" ……… It's Really been "Slow" Once TodayThey Say "It's Dead" ……… It's Really been "Slow" Once Today

Can Other Clients get to the Server?Can Other Clients get to the Server?• They Say "No One" ………It's Really "Everyone Can"They Say "No One" ………It's Really "Everyone Can"

When Did it Work Last?When Did it Work Last?• They Say "Last Week" …… It's Really "Never"They Say "Last Week" …… It's Really "Never"

What Changed?What Changed?• They Say "Nothing" ……… It's Really their Kids Game They InstalledThey Say "Nothing" ……… It's Really their Kids Game They Installed

Is the Client Properly Configured?Is the Client Properly Configured?• They Say "Yes" ……….. They Don't know what a Computer isThey Say "Yes" ……….. They Don't know what a Computer is

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TroubleshootingBasics

Server Considerations Considerations ONLY GATHER FACTS……….ONLY GATHER FACTS………...

Is it Static or DHCP?Is it Static or DHCP?

Can the Server Resolve Names?Can the Server Resolve Names?

When Did it Work Last?When Did it Work Last?

What Changed?What Changed?

Is the Server Properly Configured?Is the Server Properly Configured?

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Parts to Troubleshoot Separate the network from the ServersSeparate the network from the Servers

Cables, Switches and Routers are the NetCables, Switches and Routers are the Net Computers are the Clients and ServersComputers are the Clients and Servers If the Network has a Problem Usually If the Network has a Problem Usually

Several People are AffectedSeveral People are Affected Check the Physical LayerCheck the Physical Layer

Is it the Correct CableIs it the Correct Cable Is there a Link LightIs there a Link Light Does another Computer work in the portDoes another Computer work in the port

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Parts to Troubleshoot Check the Computer ConfigurationCheck the Computer Configuration

• http://inside.us.dell.com/it/is/network/http://inside.us.dell.com/it/is/network/

Configuration Docs

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Parts to Troubleshoot Check the Computer ConfigurationCheck the Computer Configuration Set CLASSID for W2K DHCP ClientsSet CLASSID for W2K DHCP Clients

Capital W2K

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Parts to Troubleshoot Check the Computer ConfigurationCheck the Computer Configuration

Class ID

WINS & DNS Servers

Domain Suffixes

Subnet Mask

Remove Name Resolution From The TestRemove Name Resolution From The Test PING Remote by IPPING Remote by IP Ping Gateway by IPPing Gateway by IP Ping Loopback (127.0.0.1)Ping Loopback (127.0.0.1) Map Drive by IP Map Drive by IP i.e. net use * \\10.180.12.26\c$i.e. net use * \\10.180.12.26\c$ Tracert to IP Tracert to IP i.e. tracert 10.180.12.26i.e. tracert 10.180.12.26 "Net View" to IP "Net View" to IP i.e. net view \\10.180.12.26i.e. net view \\10.180.12.26

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NOTE: Resolve ALL IP Issues Prior to NOTE: Resolve ALL IP Issues Prior to Troubleshooting Name Resolution IssuesTroubleshooting Name Resolution Issues

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PING IP ExamplePING IP Example

Try to Resolve Name

Name Resolved

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Tracert ExampleTracert Example

Not Found

Found

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Netstat SyntaxNetstat Syntax

Switches

"/?" Display Help

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Netstat -a ExampleNetstat -a Example

Protocol

Port State

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Netstat -n ExampleNetstat -n Example

Protocol

Port State

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Netstat -r ExampleNetstat -r Example

Remote

Default Gateway

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Netstat -s ExampleNetstat -s Example

Is Data Moving ?

Part 2 Part 2 NetBIOS TroubleshootingNetBIOS Troubleshooting

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Client Considerations Considerations

Can Not Login to the DomainCan Not Login to the Domain• "No Domain Controller Found""No Domain Controller Found"

Can Not Map a Drive by NameCan Not Map a Drive by Name• "Host Name Not Found""Host Name Not Found"

Can Not "Net View" a computerCan Not "Net View" a computer• "Host Name Not Found""Host Name Not Found"

What WINS Server are they usingWhat WINS Server are they using

Can Other Computers Map Drives by NameCan Other Computers Map Drives by Name

Does Not Need to Register with WINS to Does Not Need to Register with WINS to ResolveResolve

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TroubleshootingNBNS (WINS)

Server Considerations Considerations

Are all the Services Registered in WINS?Are all the Services Registered in WINS?

• The Name Resolution is up to the Client if all the The Name Resolution is up to the Client if all the Server Services are Registered in WINSServer Services are Registered in WINS

If the Server is down several people are If the Server is down several people are having the having the SAMESAME problem(s) problem(s)

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Add Name Resolution To The TestAdd Name Resolution To The Test "Nbtstat" to "Short Name""Nbtstat" to "Short Name"

• i.e. nbtstat -a \\ausgnsnpt01i.e. nbtstat -a \\ausgnsnpt01

"Net View" to "Short Name""Net View" to "Short Name"• i.e. net view \\ausgnsnpt01i.e. net view \\ausgnsnpt01

Map Drive by "Short Name"Map Drive by "Short Name"• i.e. net use * \\ausgnsnpt01\c$i.e. net use * \\ausgnsnpt01\c$

PING Remote by "Short Name"PING Remote by "Short Name"• i.e. Ping ausgnsnpt01i.e. Ping ausgnsnpt01

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Switches


Nbtstat SyntaxNbtstat Syntax"/?" Display Help

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"-a" RemoteServices & MAC


Nbtstat -a ExampleNbtstat -a Example

"-n" LocalServices NO MAC

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Nbtstat -c ExampleNbtstat -c Example

"-c" Cache "-r" Resolved

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Nbtstat -s and -RR ExampleNbtstat -s and -RR Example

"-s or -S" Sessions

"-RR" ReRegister with WINS

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Net View Syntax and ExampleNet View Syntax and ExampleShow Browse List

"Short Name"

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Net Use Syntax and ExampleNet Use Syntax and Example

Map next Drive Letter

Ask for Password

Delete Map

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"Short Name" Resolved by Broadcast or WINS


PING ExamplePING Example

Note: PING is a DNS Command for FQDN but can be Note: PING is a DNS Command for FQDN but can be used to troubleshoot Net BIOSused to troubleshoot Net BIOS

FQDN Name Resolved by DNS

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Clear the LMHOST file if not needed or you are

troubleshooting


LMHOST FileLMHOST File

Part 3 Part 3 FQDN TroubleshootingFQDN Troubleshooting

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Client Considerations Considerations

Does the App use FQDNs?Does the App use FQDNs?

Is the Domain Suffix Correct?Is the Domain Suffix Correct?

Check for the correct Name ServerCheck for the correct Name Server

Is the IP Address in DNS or DDNSIs the IP Address in DNS or DDNS• us.dell.com - Legacyus.dell.com - Legacy

• aus.amer.dell.com - W2Kaus.amer.dell.com - W2K

Can Not Map a Drive by FQDNCan Not Map a Drive by FQDN

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TroubleshootingDNS/DDNS (FQDN)

Server Considerations Considerations

Is the Name in DNS or DDNS?Is the Name in DNS or DDNS?

• The Name Resolution is up to the Client if the server The Name Resolution is up to the Client if the server is in DNS or DDNS it has met the minimum is in DNS or DDNS it has met the minimum requirementsrequirements

If the Server is down several people are If the Server is down several people are having the having the SAMESAME problem(s) problem(s)

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NSLookup SyntaxNSLookup SyntaxShow Commands

Commands

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NSLookup ExampleNSLookup Example

Query Returned

Authoritativeamer.dell.comDDNS Server

Query Returned

Non-Authoritativeamer.dell.comDDNS Server

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NSLookup ExampleNSLookup Example

Query Returned

Non-Authoritativeus.dell.com

DDNS Server

Query ReturnedNo DNS Entry

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PING SyntaxPING Syntax

Show Syntax

Switches

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PING ExamplePING Example PING Loop Back AddressPING Loop Back Address

• TCP/IP is Installed ProperlyTCP/IP is Installed Properly

Loop Back Address

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Domain Suffix Search Order

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Ping Short Name




WINS Responded with "Short Name"

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Ping Short Name


DDNS Responded with FQDN

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PING ExamplePING Example PING Loop Back Name in Host FilePING Loop Back Name in Host File

• TCP/IP is Installed ProperlyTCP/IP is Installed Properly

• Host File is WorkingHost File is Working

Loop Back Name "Localhost"

Name Resolution

Presented Presented By By

Tom BattagliaTom BattagliaThomas Text

name resolution

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