Module 3: Resolving Names
Overview
• Multimedia: Introduction to the Name
Resolution Process
• Viewing Names on a Client • Configuring Host Name Resolution • Configuring NetBIOS Name Resolution
Multimedia: Introduction to the Name Resolution Process
• Presentation topic: Overview of the
name resolution process
• Presentation learning objectives
include the ability to: – Explain what a host name is – Explain what a NetBIOS name is – Describe how the name resolution
process works
Lesson: Viewing Names on a Client
• How Names Are Mapped to IP Addresses • What Are Host Names? • What Are NetBIOS Names? • Practice: Viewing Names on a Client
How Names Are Mapped to IP Addresses
Name Resolution Name Resolution Service Service
Computer44 1
192.168.1.200
2
Where is Where is the the Computer Computer 44 file? 44 file?
3
Computer44 Computer44
What Are Host Names?
A host name is the DNS name of a device A host name is the DNS name of a device on a network on a network
Examples: Examples:
“.” root “.” root
FQDN
msftmsft
server1.contoso.msft.
contoso contoso
DNS suffix host Name
training training FQDN
server1.training.contoso.msft. Server1 = 192.168.0.66 Server1 = 192.168.0.66
DNS suffix host Name Server1 = 192.168.0.67 Server1 = 192.168.0.67
What Are NetBIOS Names?
A NetBIOS name is 16-character identifier A NetBIOS name is 16-character identifier used by NetBIOS services that are running used by NetBIOS services that are running on a computer on a computer
Services
IP address
NetBIOS name
16th character
Server2 Server2
00 20
workstation server
192.168.0.39 192.168.0.39
Server2
03
messenger
192.168.0.39
Server2 Server2
Practice: Viewing Names on a Client
In this practice, you will view host names and NetBIOS names on a computer
Lesson: Configuring Host Name Resolution
• Host Name Resolution Process • Client Resolver Cache • Hosts File • Practice: Configuring Host Name Resolution
Host Name Resolution Process
NetBIOS
DNS
Name Cache WINS BroadcastLmhost File
192.168.1.35
2
Client Resolver Cache/Hosts File 1 Salescomputer2
What is the What is the IP address IP address for for Salescomput Salescomput er2? er2?
3
Salescomputer2 Salescomputer2
Host name resolution is the Host name resolution is the process of resolving a host process of resolving a host name to an IP address name to an IP address
Client Resolver Cache
The client resolver cache stores recently resolved The client resolver cache stores recently resolved host names and host name mappings that are host names and host name mappings that are loaded from the Hosts file loaded from the Hosts file
Computer1 Computer1
Hosts File Hosts File Resolved host names Resolved host names from the DNS server from the DNS server
Hosts File
The Hosts file is a static local file that contains The Hosts file is a static local file that contains mappings for host name-to-IP addresses mappings for host name-to-IP addresses
# Copyright (c) 19931999 Microsoft Corp. # Copyright (c) 19931999 Microsoft Corp. # # # This is a sample HOSTS file used by Microsoft TCP/IP for # This is a sample HOSTS file used by Microsoft TCP/IP for
Windows. Windows.
# # # This file contains the mappings of IP addresses to host # This file contains the mappings of IP addresses to host
names. Each names. Each
# entry should be kept on an individual line. The IP # entry should be kept on an individual line. The IP
Computer1 Computer1
address should address should
# be placed in the first column followed by the # be placed in the first column followed by the
corresponding host name. corresponding host name.
# The IP address and the host name should be separated by # The IP address and the host name should be separated by
at least one at least one
# space. # space. # # # Additionally, comments (such as these) may be inserted on # Additionally, comments (such as these) may be inserted on
individual individual
# lines or following the machine name denoted by a '#' # lines or following the machine name denoted by a '#'
symbol. symbol.
Hosts File Hosts File
# # # For example: # For example: # # # 102.54.94.97 rhino.acme.com # source # 102.54.94.97 rhino.acme.com # source
server server
# 38.25.63.10 x.acme.com # x # 38.25.63.10 x.acme.com # x
client host client host
127.0.0.1 localhost 127.0.0.1 localhost
Practice: Configuring Host Name Resolution
In this practice, you will configure host name resolution
Lesson: Configuring NetBIOS Name Resolution
• NetBIOS Name Cache • NetBIOS Name Resolution Process • Local Broadcasts • Lmhosts File • Practice: Configuring NetBIOS Name Resolution
NetBIOS Name Cache
A NetBIOS name cache is a location in memory that A NetBIOS name cache is a location in memory that stores NetBIOS names that have recently been stores NetBIOS names that have recently been resolved to IP addresses resolved to IP addresses
Computer1 Computer1
Broadcast
Resolved Host Names Resolved Host Names from Broadcasts from Broadcasts Lmhosts File Lmhosts File
Resolved Host Names Resolved Host Names from the WINS server from the WINS server
NetBIOS Name Resolution Process
NetBIOS
Name Cache WINS BroadcastLmhost File
Salescomputer2
1
2 192.168.1.35
What is the What is the IP address IP address for for Salescomput Salescomput er2? er2?
3
Salescomputer2 Salescomputer2
NetBIOS name resolution maps a NetBIOS name resolution maps a NetBIOS name to an IP address NetBIOS name to an IP address
Local Broadcasts
Local broadcasts are messages transmitted from one Local broadcasts are messages transmitted from one network computer to all devices within that computer’s network computer to all devices within that computer’s network segment network segment
2
3
Router Router Broadcast 1
1
2
NetBIOS NetBIOS Redirector Redirector
3
The NetBIOS redirector sends out a The NetBIOS redirector sends out a local broadcast local broadcast If the resource is on the local If the resource is on the local network, the broadcast is network, the broadcast is answered, and an IP address is answered, and an IP address is returned returned If the resource is on a remote If the resource is on a remote network, the broadcast will not network, the broadcast will not pass through the router pass through the router
Lmhosts File
An Lmhosts file is a local text file that maps An Lmhosts file is a local text file that maps NetBIOS names to IP addresses NetBIOS names to IP addresses
# Copyright (c) 19931999 Microsoft Corp. # Copyright (c) 19931999 Microsoft Corp. # # # This is a sample LMHOSTS file used by the Microsoft TCP/IP for # This is a sample LMHOSTS file used by the Microsoft TCP/IP for
Windows. Windows.
# # # This file contains the mappings of IP addresses to # This file contains the mappings of IP addresses to
computernames computernames
# (NetBIOS) names. Each entry should be kept on an individual # (NetBIOS) names. Each entry should be kept on an individual
line. line.
# The IP address should be placed in the first column followed # The IP address should be placed in the first column followed
by the by the
# corresponding computername. The address and the computername # corresponding computername. The address and the computername # should be separated by at least one space or tab. The "#" # should be separated by at least one space or tab. The "#"
Computer1 Computer1
character character
# is generally used to denote the start of a comment (see the # is generally used to denote the start of a comment (see the
exceptions exceptions
# below). # below). # # # The following example illustrates all of these extensions: # The following example illustrates all of these extensions: # # # 102.54.94.97 rhino #PRE #DOM:networking # 102.54.94.97 rhino #PRE #DOM:networking
#net group's DC #net group's DC
# 102.54.94.102 "appname \0x14" # 102.54.94.102 "appname \0x14"
#special app server #special app server
# 102.54.94.123 popular #PRE # 102.54.94.123 popular #PRE
#source server #source server
# 102.54.94.117 localsrv #PRE # 102.54.94.117 localsrv #PRE
#needed for the include #needed for the include
Lmhosts File Lmhosts File
