Guide to Microsoft Windows Server 2003 Command Line Administration

1
Guide toMicrosoft Windows Server 2003Command
Line Administration

• Chapter 7
• Introduction to Networking

2
Objectives

• Understand how systems communicate
• Understand basic networking protocols
• Utilize commands to diagnose, configure, and
  troubleshoot networks using TCP/IP
• Use commands to manage networks
• Improve the security of networks

3
Overview of TCP/IP

• Many protocols are used in the networking world
• Protocols are rules for formatting, ordering, and
  error-checking data sent across a
  network
• Transmission Control Protocol/Internet Protocol
  (TCP/IP) is a set of protocols that provides the
  basis for operation of the Internet TCP includes
  rules that a computer uses to make and break
  connections, and IP determines the routing of
  data over the Internet
• TCP/IP is considered a protocol suite, or a
  collection of protocols, including TCP, IP, FTP,
  HTTP, SNMP, Telnet, LDAP, ICMP, and other
  protocols that work behind the scenes on a
  computer

4
How Systems Communicate

• For computers to communicate with one another,
  they need to speak the same language - protocols
  act as these languages
• Protocols allow networked computers, also called
  hosts or nodes, to send and receive data part of
  the job of a protocol is to identify hosts on a
  network
• Hosts that are connected to the Internet and are
  responsible for determining the best way for data
  to reach its destination are known as routers
• All major networking protocols use an addressing
  scheme to identify hosts a portion of the
  address identifies the network segment where the
  host exists, while the other portion identifies
  the unique host

5
Network and Host Portions of an IP Address
6
How Systems Communicate (Cont.)

• Data that travels over a network is transmitted
  in packets packets are small pieces of files and
  e-mail messages that travel over networks and are
  reassembled into their original form upon
  reaching their destination
• When one host wants to communicate with another,
  the first host needs to know the address of the
  second host in order to establish a session
  (which is like a conversation)
• The protocol makes sure that the data is
  exchanged and done so in a way that the receiving
  host can translate it
• To make sure that protocols follow standards, the
  ISO developed the Open Systems Interconnect (OSI)
  model

7
OSI Model
8
Comparison of OSI and TCP/IP
9
Identifying Hosts

• A host can be one of several types of computers
  on a network - a server, a client, or a
  workstation
• A server provides data and applications to
  clients clients are devices (such as computers
  or printers) that request a service and
  workstations are where users work
• The Windows Server 2003 environment mostly deals
  with servers and clients, since it does not run
  on workstations
• TCP/IP dynamically assigns IP addresses to hosts
  via a Dynamic Host Configuration Protocol (DHCP)
  server
• On a Windows Server 2003 system, use a static IP
  address administrators do this in the Internet
  Protocol properties of a network interface card
  (NIC)

10
TCP/IP Properties Dialog Box
11
IP Address Settings
12
Maintaining a Network Using Commands

• The network commands that an administrator uses
  to manage a network fall into three categories
  diagnostic, troubleshooting, and configuration

13
Diagnostics

• Diagnostic commands provide real-time information
  that can highlight issues before they arise
• NETSTAT displays protocol statistics (such as
  routing table entries on the server) and current
  TCP/IP network connections that exist or are
  being made
• NETDIAG displays NIC statistics and runs NIC
  diagnostics
• NETDIAG is not installed by default with Windows
  Server 2003, however it can be downloaded from
  Microsoft

14
Troubleshooting

• Troubleshooting commands provide data which leads
  to problem determination
• The PING command determines whether or not TCP/IP
  is working on the target computer this is
  referred to as pinging the target computer and is
  typically done when an attempt to connect to a
  network device fails
• If the PING command is successful, use TRACERT to
  display the name and IP address of every router
  that the data packet travels across on the
  network TRACERT shows the timing for each step,
  or hop, between routers
• PATHPING goes beyond TRACERT and displays the
  network statistics between each hop

15
PING Responses
16
Loopback PING Results
17
TRACERT Results from Yahoo.com
18
Data Packet Statistics
19
Configuration

• Configuration commands are specifically designed
  to set network settings and information
• The IPCONFIG command displays the basic IP
  configuration information on an interface
• IPCONFIG is used frequently when dealing with
  clients on a Windows Server 2003 system,
  computers will likely have more than one NIC, and
  this command provides fast, reliable information
  about the IP address, subnet mask, and default
  gateway, if set
• Basic configuration can be done using the
  /RELEASE or /RENEW options of the IPCONFIG
  command basic configuration of the DNS is done
  with the /FLUSHDNS, /DISPLAYDNS, and /REGISTERDNS
  options

20
Results of the IPCONFIG/ALL Command
21
Results of the IPCONFIG/DISPLAYDNS Command
22
Configurations (Cont.)

• The ROUTE command manipulates routing tables and
  is available only if TCP/IP is installed on the
  network
• When dealing with static routes to servers or
  hosts, ROUTE can be very handy
• There are four commands that are used in
  combination with ROUTE ROUTE ADD adds a
  specified static route to the routing table
  through the identified gateway Route PRINT
  displays a list of registered routes in the
  routing table ROUTE CHANGE modifies an existing
  route ROUTE DELETE deletes a static route from a
  routing table
• When used with the ROUTE ADD command, /P makes a
  route persistent every time the system is booted

23
Network Management/FTP

• Managing the network and its files efficiently
  requires many commands and protocols
• File Transfer Protocol (FTP) is a TCP/IP protocol
  that allows file management over networks
• Using FTP, files are uploaded (sent) and
  downloaded (received) between FTP-compliant
  network servers
• The FTP command allows for access to an FTP site,
  where typically a username and password are
  required
• FTP operates in its own environment, once the FTP
  site is entered, there are more than 50
  FTP-specific commands such as DIR to display
  directory contents TYPE to assess file transfer
  mode in use (ASCII or binary) PUT to upload
  files and GET to download files

24
Typical Welcome Message in FTP
25
Starting an FTP Download with Hash Marks
26
Completed FTP Download
27
FTP Commands
28
FTP Commands (Cont.)
29
Welcome Banner from the Course Technology FTP Site
30
Files Available for Download from the Course
Technology FTP Server
31
NETBIOS

• NetBIOS is a high-level programming language
  interface that was originally intended to be used
  with MS-DOS, but was also used by Windows OSs
  prior to Windows 2000
• If the network is entirely Windows Server 2003,
  then NetBIOS is not needed however, most
  networks still need to integrate legacy OSs that
  require NetBIOS
• NetBIOS is not routable by default (unlike
  TCP/IP), and needs help traversing the network
  NetBIOS can reach beyond its local network by
  piggybacking on TCP/IP NetBT allows this
  piggybacking to happen
• To start NetBIOS over TCP/IP, use the NET START
  command to start the NetBT service

32
Telnet

• Telnet is a terminal emulation protocol for
  TCP/IP
• The Telnet utility runs on the local machine and
  connects it to a server on the network
• Commands are entered locally through Telnet, and
  they are executed as if they were being directly
  entered on the remote server, enabling control of
  the server
• To start a Telnet session, log into a server
  using an authorized username and password
• Telnet is a common way to remotely control Web
  servers, routers, switches, and other networking
  equipment

33
Security

• Network access increases the need for security
• Many types of Windows Server 2003 objects have
  associated ACLs, including all Active Directory
  objects, local NTFS files and folders, the
  registry, and printers
• To see the NTFS permissions for an object,
  right-click it and select Properties select the
  Security tab to view the Discretionary ACL (DACL)
• Administrators use the CALCS command to gain
  greater and more specific control of ACLs
• CALCS are used to modify the ACL on files or
  directories this is often useful for adding or
  deleting user or group permissions without
  modifying other existing permissions

34
Security (Cont.)

• Network access increases the need for security
• NTFS file and folder permissions are in effect
  when accessed locally and over the network
• NTFS folder permissions include Full Control,
  Modify, Read Execute, List Folder Contents,
  Read, and Write
• NTFS file permissions include Full Control,
  Modify, Read Execute, Read, and Write
• NTFS permissions are affected by copying and
  moving files or folders whether they retain
  their current setting, obtain the permissions of
  the destination partition, or lose all
  permissions, depends on the partition that they
  are copied or moved to

35
Chapter Summary

• Hosts communicate using protocols (the most
  popular of the protocols in use is TCP/IP)
• Primarily, hosts use the DNS naming convention
  however, due to legacy software and applications,
  NetBIOS names are used as well

36
Chapter Summary (Cont.)

• Networking commands fall into three basic
  categories diagnostics, configuration, and
  troubleshooting
• Diagnostic commands give you real-time
  information that can be used to identify problems
• Configuration commands allow you to create
  settings in your networking protocols or on NICs
• Troubleshooting commands allow you to find issues
  that are causing network problems

37
Chapter Summary (Cont.)

• FTP, part of the TCP/IP suite, allows a host to
  transfer or download files to a Windows Server
  2003 system running FTP services
• NetBIOS names are used by legacy applications
  and software
• The protocol that transports NetBIOS is called
  NetBEUI
• NetBEUI is not routable like TCP/IP, so it uses
  NetBEUI over TCP (NetBT) to route over network
  segments

38
Chapter Summary (Cont.)

• Telnet, which is another popular application that
  is part of TCP/IP, allows a user to remotely
  administer a host as if the user was at the host
• Security is vital to any business
• Discretionary ACLs (DACLs) show which users are
  allowed access to objects on your computer
• Permissions through DACLs can be assigned on
  files and folders with NTFS permissions as well
  as through Shared File and Folder permissions

39
Command Summary
40
Command Summary (Cont.)