name resolutionpresentedby tom battaglia thomas text
TRANSCRIPT
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
Thomas Text
Section 1 of 4 Section 1 of 4 Resolution Methods Defined Resolution Methods Defined
Thomas Text
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
Thomas Text
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
Thomas Text
Broadcast for Broadcast for NetBIOS "Short" NameNetBIOS "Short" Name
Thomas Text
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
Thomas Text
Windows Internet Name Service Windows Internet Name Service (WINS)(WINS)
Note: Microsoft Windows Clients Only
Thomas Text
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
Thomas Text
Resolution Methods DefinedWINS
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
Resolution Methods DefinedWINS
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
Thomas Text
Resolution Methods DefinedWINS
WINS – MMC ExampleWINS – MMC Example
Thomas Text
Resolution Methods DefinedWINS
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
Thomas Text
Resolution Methods DefinedWINS
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
Thomas Text
Domain Name Service Domain Name Service (DNS)(DNS)
Thomas Text
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
Thomas Text
Resolution Methods DefinedDNS
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
Thomas Text
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
Thomas Text
Resolution Methods DefinedDNS
DNS – DNS – Forward Lookup MMC Example MMC Example
Host Names
IP Address
IP Alias
Thomas Text
Resolution Methods DefinedDNS
DNS – DNS – Forward Lookup Unix Example Unix Example
Host Names
IP Address
IP AliasThomas Text
Resolution Methods DefinedDNS
DNS – DNS – Reverse lookup MMC Example MMC Example
IP - First Octet
Host Names
Thomas Text
Resolution Methods DefinedDNS
DNS – DNS – Reverse lookup Unix Example Unix Example
Filename
IP - First Octet
Host Names
Thomas Text
Dynamic Domain Name Dynamic Domain Name ServiceService(DDNS)(DDNS)
Thomas Text
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
Resolution Methods DefinedDDNS
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
Thomas Text
Resolution Methods DefinedDDNS
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
Thomas Text
Resolution Methods DefinedDDNS
DDNS – DDNS – Forward Lookup MMC ExampleMMC Example
IP Address
Host NamesThomas Text
Resolution Methods DefinedDDNS
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
Thomas Text
Section 2 of 4 Section 2 of 4 Microsoft Name Resolution Microsoft Name Resolution
Thomas Text
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
Thomas Text
Part 1 Part 1 Resolution MethodsResolution Methods
Thomas Text
Microsoft Name Resolution
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
Thomas Text
Microsoft Name Resolution
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
Thomas Text
Microsoft Name Resolution
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
Thomas Text
Microsoft Name Resolution
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
Thomas Text
Microsoft Name Resolution
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
Thomas Text
LMHOST File Example Example
LMHOST File - No Extension
LMHOST Sample File
Examples
Microsoft Name Resolution
Thomas Text
Microsoft Name Resolution
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
Thomas Text
HOST File Example Example
HOST File - No Extension
Examples
Microsoft Name Resolution
Thomas Text
Part 2Part 2Combined Resolution MethodsCombined Resolution Methods
Thomas Text
Microsoft Name Resolution
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
Thomas Text
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
Microsoft Name Resolution
Thomas Text
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
Microsoft Name Resolution
H-NodeH-Node
Cache
WINS
Broadcast
LMHOST File
HOST File
DNS Server
Time OutThomas Text
Microsoft Name Resolution
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
Thomas Text
Microsoft Name Resolution
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
Thomas Text
Section 3 of 4 Section 3 of 4 The OSI ModelThe OSI Model
Thomas Text
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
Thomas Text
Open Systems Interconnection (OSI) Model
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
Open Systems Interconnection (OSI) Model
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
Thomas Text
Open Systems Interconnection (OSI) Model
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
Thomas Text
Open Systems Interconnection (OSI) Model
ApplicationApplication PresentationPresentation SessionSession TransportTransport NetworkNetwork Data LinkData Link PhysicalPhysical
ApplicationApplication PresentationPresentation SessionSession TransportTransport NetworkNetwork Data LinkData Link PhysicalPhysical
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"
Thomas Text
Open Systems Interconnection (OSI) Model
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
Thomas Text
Open Systems Interconnection (OSI) Model
"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
Thomas Text
Open Systems Interconnection (OSI) Model
"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
Thomas Text
Open Systems Interconnection (OSI) Model
"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
Thomas Text
Open Systems Interconnection (OSI) Model
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
Open Systems Interconnection (OSI) Model
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
Thomas Text
Open Systems Interconnection (OSI) Model
Layer 7 Layer 6 Layer 5 Layer 4 Layer 3 Data LinkData Link Layer 1
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
Thomas Text
Open Systems Interconnection (OSI) Model
Layer 7 Layer 6 Layer 5 Layer 4 Layer 3 Data LinkData Link Layer 1
Thomas Text
Open Systems Interconnection (OSI) Model
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
Thomas Text
Open Systems Interconnection (OSI) Model
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
Thomas Text
Section 4 of 4 Section 4 of 4 Troubleshooting Troubleshooting
Thomas Text
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
Thomas Text
Part 1 Part 1 Basic Network TroubleshootingBasic Network Troubleshooting
Thomas Text
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
Thomas Text
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?
Thomas Text
TroubleshootingBasics
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
Thomas Text
TroubleshootingBasics
Thomas Text
TroubleshootingBasics
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
Thomas Text
TroubleshootingBasics
Parts to Troubleshoot Check the Computer ConfigurationCheck the Computer Configuration Set CLASSID for W2K DHCP ClientsSet CLASSID for W2K DHCP Clients
Capital W2K
Thomas Text
TroubleshootingBasics
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
Thomas Text
TroubleshootingBasics
NOTE: Resolve ALL IP Issues Prior to NOTE: Resolve ALL IP Issues Prior to Troubleshooting Name Resolution IssuesTroubleshooting Name Resolution Issues
Thomas Text
TroubleshootingBasics
PING IP ExamplePING IP Example
Try to Resolve Name
Name Resolved
Thomas Text
TroubleshootingBasics
Tracert ExampleTracert Example
Not Found
Found
Thomas Text
TroubleshootingBasics
Netstat SyntaxNetstat Syntax
Switches
"/?" Display Help
Thomas Text
TroubleshootingBasics
Netstat -a ExampleNetstat -a Example
Protocol
Port State
Thomas Text
TroubleshootingBasics
Netstat -n ExampleNetstat -n Example
Protocol
Port State
Thomas Text
TroubleshootingBasics
Netstat -r ExampleNetstat -r Example
Remote
Default Gateway
Thomas Text
TroubleshootingBasics
Netstat -s ExampleNetstat -s Example
Is Data Moving ?
Part 2 Part 2 NetBIOS TroubleshootingNetBIOS Troubleshooting
Thomas Text
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
Thomas Text
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)
Thomas Text
TroubleshootingNBNS (WINS)
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
Thomas Text
TroubleshootingNBNS (WINS)
Thomas Text
Switches
TroubleshootingNBNS (WINS)
Nbtstat SyntaxNbtstat Syntax"/?" Display Help
Thomas Text
"-a" RemoteServices & MAC
TroubleshootingNBNS (WINS)
Nbtstat -a ExampleNbtstat -a Example
"-n" LocalServices NO MAC
Thomas Text
TroubleshootingNBNS (WINS)
Nbtstat -c ExampleNbtstat -c Example
"-c" Cache "-r" Resolved
Thomas Text
TroubleshootingNBNS (WINS)
Nbtstat -s and -RR ExampleNbtstat -s and -RR Example
"-s or -S" Sessions
"-RR" ReRegister with WINS
Thomas Text
TroubleshootingNBNS (WINS)
Net View Syntax and ExampleNet View Syntax and ExampleShow Browse List
"Short Name"
Thomas Text
TroubleshootingNBNS (WINS)
Net Use Syntax and ExampleNet Use Syntax and Example
Map next Drive Letter
Ask for Password
Delete Map
Thomas Text
"Short Name" Resolved by Broadcast or WINS
TroubleshootingNBNS (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
Thomas Text
Clear the LMHOST file if not needed or you are
troubleshooting
TroubleshootingNBNS (WINS)
LMHOST FileLMHOST File
Part 3 Part 3 FQDN TroubleshootingFQDN Troubleshooting
Thomas Text
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
Thomas Text
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)
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
NSLookup SyntaxNSLookup SyntaxShow Commands
Commands
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
NSLookup ExampleNSLookup Example
Query Returned
Authoritativeamer.dell.comDDNS Server
Query Returned
Non-Authoritativeamer.dell.comDDNS Server
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
NSLookup ExampleNSLookup Example
Query Returned
Non-Authoritativeus.dell.com
DDNS Server
Query ReturnedNo DNS Entry
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
PING SyntaxPING Syntax
Show Syntax
Switches
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
PING ExamplePING Example PING Loop Back AddressPING Loop Back Address
• TCP/IP is Installed ProperlyTCP/IP is Installed Properly
Loop Back Address
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
PING ExamplePING Example
Domain Suffix Search Order
Thomas Text
Ping Short Name
TroubleshootingDNS/DDNS (FQDN)
PING ExamplePING Example
Domain Suffix Search Order
WINS Responded with "Short Name"
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
PING ExamplePING Example
Ping Short Name
Domain Suffix Search Order
DDNS Responded with FQDN
Thomas Text
TroubleshootingDNS/DDNS (FQDN)
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