Network Protocols

1
Network Protocols

• Chapter Seven

2
Windows XP Network Components

• Interact with a network without requiring
  additional software
• Function as a network client or as a network
  server (or both)
• Participate in peer-to-peer, client/server, and
  terminal/host environments

3
Windows XP Network Components

• Have everything needed to access the Internet
  (e.g., protocols and client capabilities, a
  powerful Web browser Internet Explorer)
• Support multiple protocols easily and
  transparently (API)
• Can be added to or deleted from a Windows XP
  system without affecting function of other
  components

4
Network Protocols

• NWLink (IPX/SPX)
• Works best on networks of medium scope (lt20
  servers in a single facility)
• Important on networks that include Novell servers

5
Network Protocols

• TCP/IP (Transmission Control Protocol/ Internet
  Protocol)
• Works on a global scale
• Scales well from small networks all the way up to
  the Internet
• Most widely used of all networking protocols

6
NWLink

• Microsofts implementation of Novells
  Internetwork Packet Exchange/Sequenced Packet
  Exchange IPX/SPX protocol stack
• Works with the NDIS (Network Driver Interface
  Specification) driver technology native to
  Windows XP
• Defines parameters for loading more than one
  protocol on a network adapter
• Supports most important IPX/SPX APIs
• Novells Windows Sockets
• NetBIOS over IPX

7
NWLink

• Advantages
• SPX II
• Autodetection of frame types
• Direct hosting over IPX
• Drawbacks
• May not scale well on large networks
• Lack of built-in facility for centralized address
  management allows address conflicts to occur
• Failure to support network management tools
• Large memory footprint on DOS machines

8
TCP/IP

• Most common networking protocol in use worldwide
  makes the Internet possible
• Platform for a variety of network services
• Newsgroups (NNTP)
• Electronic mail (SNMP and MIME)
• File transfer (FTP and ANS)
• Remote printing (lpr, lpd, lpq utilities)
• Remote boot (bootp and DHCP)
• The World Wide Web (HTTP)

9
TCP/IP Advantages

• Supports networking services better than other
  protocols through its multiple components
• Supports multiple routing protocols that can
  support large, complex networks
• Incorporates better error detection and handling
  and works with more kinds of computers than other
  protocols

10
TCP/IP Advantages

• Also supports the following
• Direct Internet access from any TCP/IP equipped
  computer
• Powerful network management protocols and
  services (SNMP and DMI)
• Dynamic Host Configuration Protocol (DHCP)
• Windows Internet Naming Service (WINS)

11
TCP/IP Components
FTP
HTTP
Telnet
SMTP
Others
TCP
UDP
ICMP
Routing Protocols
DNS
RARP
BOOTP
IP
X.25
Ethernet II
ATM
FDDI
IEEE802.x
12
Protocols in the Windows TCP/IP Stack
13
TCP/IP Drawbacks

• Not extremely fast or easy to use
• Requires a fair degree of expertise, careful
  planning, and constant maintenance and attention

14
Interprocess Communication (IPC)

• Mechanism that defines a way for internal Windows
  processes to exchange information

15
Interprocess Communication (IPC)
16
Categories of IPC Mechanisms

• Programming interfaces
• Permit general, open-ended client/server dialog
  as mediated by applications or system services
• Individual APIs differ depending on kinds of
  client-server dialog supported
• File systems
• Support file sharing between clients and servers

17
IPC File System Mechanisms

• Interfaces for file system access
• Named pipes
• Mailslots file system
• Work through the Windows XP redirector, which
  distinguishes between local and network resource
  requests
• Permits one simple set of file I/O commands to
  handle both local and network access to file
  system data

18
Named Pipes

• Support a connection-oriented message-passing
  service for clients and servers
• Offer a reliable method for clients and servers
  to exchange requests, replies, and associated
  files
• Provide their own methods to ensure reliable data
  transfer
• Include a security feature called impersonation

19
Mailslots File System

• Offers no delivery guarantees
• Does not acknowledge successful receipt of data
• Used as an internal method of supporting
  nonessential system-to-system communications

20
IPC Programming Interfaces

• NetBIOS
• Windows Sockets
• RPC
• NetDDE

21
NetBIOS

• Widely used but simple-minded
• Easy to program
• Required to permit a Microsoft Windows network to
  operate
• Works well with all TDI-compliant transports
  (NetBEUI, NWLink, and TCP/IP)

22
Windows Sockets (WinSock)

• Define a standardized and broadly deployed
  interface to network transports such as TCP/IP
  and IPX
• Appear in many programs that originated as UNIX
  programs and include the majority of Internet
  utilities (especially the most popular IP
  utilities, such as Web browsers, e-mail software,
  and file transfer programs)

23
RPC

• Implements IPC tools that can invoke separate
  programs on remote computers, supply them with
  input, and collect results
• Indifferent to where client and server portions
  reside
• Basic components
• Remote stub procedure
• RPC run-time system
• Application stub procedure
• Remote procedure(s)

24
Network Dynamic Data Exchange (NetDDE)

• Creates ongoing data streams (exchange pipes)
  between two applications across a network
• Extends local DDE across the network

25
Other IPC Programming Interfaces

• Distributed Component Object Model (DCOM)
• Facilitates communication of application
  components over a network by providing a
  reliable, secure, and efficient mechanism for
  exchanging information
• Windows Network (WNet) Interface
• Allows applications to take advantage of Windows
  XP networking capabilities through a standardized
  API
• Win32 Internet API (WinInet)
• Enables applications to take advantage of
  Internet functionality without requiring
  extensive proprietary programming

26
Redirectors

• Examine all requests for system resources and
  decide whether such requests are local or remote
• Workstation service
• Server service
• Multiple Universal Naming Convention Provider
  (MUP)
• Multi-Provider Router (MPR)
• Communicate with transport protocols through the
  common TDI boundary layer

27
Redirectors
28
Server Service

• Handles creation and management of shared
  resources
• Performs security checks against requests for
  resources, including directories and printers
• Allows a Windows XP computer to act as a server
  on a client/server network, up to maximum number
  of licensed clients
• Elements
• SERVER.EXE
• SRV.SYS

29
Server Services
30
Workstation Service

• Supports client access to network resources and
  handles functions such as logging on, connecting
  to network shares (directories and printers), and
  creating links using the Windows XP IPC options
• Elements
• User mode interface
• Redirector

31
Workstation Services
32
Multiple Universal Naming Convention Provider
(MUP)

• Allows two or more UNC providers to exist
  simultaneously
• Determines which UNC provider will handle a
  particular UNC request and forwards the request
  to that provider

33
Universal Naming Convention (UNC) Names

• Represent the format used in NetBIOS-oriented
  name resolution systems
• Example
• \\computername\sharename\dir-path\filename.ext

34
Multi-Provider Router (MPR)

• Can designate the proper redirector to handle a
  resource request that does not use UNC naming
• Lets applications written to older Microsoft
  specifications behave as if they used UNC naming
• Able to recognize those UNCs that correspond to
  defined drive mappings

35
Multi-Provider Router (MPR)
36
Networking Under Windows XP

• Controlled by Network and Dial-up Connections
• A single multifaceted interface that combines
  networking access for LAN, Internet, and modem
• Accessed through Settings entry in Start menu

37
Network and Dial-up Connections
38
Changing the TCP/IP Settings
39
Binding

• Process of developing a stack by linking together
  network services and protocols
• Defined in Advanced Settings dialog box

40
Binding
41
Managing Bindings

• Allows users to define exactly how network
  services operate in order to optimize network
  performance
• Windows XP uses complete binding by default,
  which can lead to system inefficiencies
• Improve system performance and decrease
  likelihood of communications errors by disabling
  all protocol bindings that are not needed or used

42
Network Bridge

• Creates a virtual bridging router between two or
  more network interfaces, effectively connecting
  multiple network segments
• Able to connect network segments even if they use
  different protocols and different topologies
• Microsoft has included the network bridging
  capability in Windows XP to help encourage the
  creation of networks both in small offices and at
  home

43
TCP/IP Architecture

• Supports easy cross-platform communications
• Provides technical foundation for the Internet
• A suite of protocols, including IP and TCP

44
Internet Protocol (IP)

• Handles routing and addressing information
• Provides a simple connectionless transmission
  that relies on higher-layer protocols to
  establish reliability
• All IP-based devices on a single network segment
  must use the same subnet mask

45
IP Addresses

• Logical addresses that are 32 bits long
• All TCP/IP addresses must be unique on the
  Internet

46
Internet Protocol (IP)

• Internet Control Message Protocol (ICMP)
• Sends control messages between IP hosts
• Address Resolution Protocol (ARP)
• Associates a logical (IP) address to a physical
  (MAC) address
• Dynamic Host Configuration Protocol (DHCP)
• Automatically configures computers

47
Transmission Control Protocol (TCP)

• The primary Internet transport protocol
• The reliable, connection-oriented, IP-based
  transport protocol that supports many of the most
  important IP services, including HTTP, SMTP, and
  FTP
• Responsible for message fragmentation and
  reassembly

48
Transmission Control Protocols

• UDP
• FTP
• Telnet
• SMTP
• SNMP
• The Berkeley R utilities

• PING
• TFTP
• The HOSTs file
• DNS
• The LMHOSTS file
• WINS

49
Transmission Control Protocols

• User Diagram Protocol (UDP)
• Lightweight, connectionless transport protocol
  used as an alternative to TCP in IP-based
  environments to supply faster, lower overhead
  access, primarily to local resources
• File Transfer Protocol (FTP)
• Provides TCP/IP-based file transfer to and from
  remote hosts

50
Transmission Control Protocols

• Telnet
• Remote terminal emulation protocol that provides
  connectivity between dissimilar systems
• Simple Mail Transfer Protocol (SMTP)
• Supports most Internet e-mail
• Simple Network Management Protocol (SNMP)
• Allows management applications to poll network
  devices and obtain status updates

51
Transmission Control Protocols

• The Berkeley R utilities
• Remote commands (including remote shell and
  remote execution)
• Packet Internet Groper (PING)
• Uses ICMP to inquire if a designated host is
  reachable on the network
• Trivial File Transfer Protocol (TFTP)
• Lightweight alternative to FTP that uses UDP to
  provide only simple get-and-put capabilities for
  file transfer on IP-based networks

52
Transmission Control Protocols

• Domain Name Service (DNS)
• Resolves names to IP addresses
• The HOSTs file
• Placed on members of a network to provide name
  resolution between hosts and IP addresses
• Resolve human names to IP addresses
• The LMHOSTS file
• Resolve NetBIOS names to IP addresses
• Windows Internet Naming Service (WINS)
• Provides NetBIOS name-IP address resolution

53
TCP/IP Configuration

• Performed through the Network and Dial-up
  Connections interface
• Potential items needed
• Unique IP address for the computer
• Subnet mask for the network
• Address of default gateway
• Address of one or more DNS servers (for IP name
  resolution)
• Address for a WINS server (for NetBIOS name
  resolution)

54
Alternate Configuration
55
TCP/IP Tools

• IPCONFIG
• Used to manage and view information related to
  DHCP and DNS
• NETSTAT
• Displays a list of active TCP connections
• NBSTAT
• Displays protocol statistics for NetBIOS over
  TCP/IP (NetBT), NetBIOS name tables, and the
  NetBIOS name cache

56
IPv6

• Microsoft has included preliminary support for
  IPv6 in Windows XP
• IPv6 aims to correct the address shortage and
  improve other aspects of TCP/IP, including
  security and efficiency
• Once IPv6 has been finalized, Microsoft will most
  likely include an IPv6 upgrade in a service pack
  or other downloadable installation module

57
Windows XP Remote Tools

• Remote Assistance
• Designed to simplify the task of training users
  or walking users through tasks
• Remote Desktop
• Similar to a single client Terminal Services for
  clients
• Developed so workers can access their work
  desktops

58
Windows XP and NetWare Networks

• Microsoft includes interconnectivity enhancements
  to allow Windows XP-based computers to connect to
  and function with NetWare servers
• Bindery
• Proprietary database that contains network
  resource information
• Novell Directory Services (NDS)
• Hierarchical database used by NetWare 4.0 and
  newer servers to store network resource and
  object data

59
NWLink

• Microsofts implementation of the IPX/SPX
  protocol suite
• Can communicate with all NetWare implementations
• IPX (Internetwork Packet Exchange)
• Connectionless protocol that provides quick
  network transport for most communications on a
  NetWare network
• SPX (Sequenced Packet Exchange)
• Connection-oriented protocol that provides
  guaranteed packet delivery

60
NWLink

• After installation is complete, NWLink has two
  configuration options available
• Ethernet frame type
• Network numbers
• By default, Windows XP determines the frame type
  in use on the network and configures itself
  accordingly

61
Client Service for NetWare (CSNW)

• Component of Windows XP Professional that allows
  Windows XP computers to access resources on
  NetWare servers version 2x, 3x, and 4x
• CSNW supports full access to
• NetWare file and print servers
• NetWare utilities
• Bindery connections
• Some NDS connections

62
File and Print Servers

• To provide access to NetWare file and print
  servers, CSNW adds a NetWare-focused redirector
  that acts as an extension of the file system, in
  much the same way that the native redirector
  supports access to Microsoft Windows Servers
• CSNW implements NetWare Core Protocol (NCP)
  requests for file and print services
• Native redirector uses the Common Internet File
  System (CIFS) for file and print services

63
Supported NetWare Utilities

• To ensure proper desktop integration in a NetWare
  server environment, CSNW supports most NetWare
  utilities and functions
• NetWare provides access to character-based
  NetWare administration utilities such as SYSCON
  and PCONSOLE
• NWLink and CSNW also support IPX burst mode

64
Bindery and NDS Support

• Versions of NetWare prior to 4.0 used the bindery
  to store their configuration information
• NetWare 4.0 uses a Novell Directory Services
  (NDS) database to store and maintain information
  that was previously stored in the bindery
• NDS is a hierarchical database that can be stored
  on multiple servers on the network
• An NDS implementation resembles a tree and is
  referred to as the NDS tree
• A network objects location in the NDS tree is
  called its context

65
Connecting to NetWare Resources

• Because Client Service for NetWare integrates so
  closely with Windows XP, connecting to NetWare
  resources works the same as connecting to other
  resources
• Choosing appropriate NetWare client software
• Because Novell also offers its Novell 32-bit
  Client for Windows, you may sometimes find
  yourself forced to choose between the Windows
  Client for NetWare Networks or the Novell
  equivalent when setting up Windows XP
  Professional workstations for network access