* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Networks and the Internet
Survey
Document related concepts
Net neutrality wikipedia , lookup
Network tap wikipedia , lookup
Airborne Networking wikipedia , lookup
Wireless security wikipedia , lookup
Net neutrality law wikipedia , lookup
Computer network wikipedia , lookup
Wake-on-LAN wikipedia , lookup
Distributed firewall wikipedia , lookup
Deep packet inspection wikipedia , lookup
Internet protocol suite wikipedia , lookup
Remote Desktop Services wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Cracking of wireless networks wikipedia , lookup
Transcript
Networks and the Internet 70-270: MCSE Guide to Microsoft Windows XP Professional Windows XP Network Overview (Page 1) Supports local area network (LAN) connections Supports emerging wireless technologies Improvement in remote access support from previous versions Windows XP Network Overview (Page 2) Can function as: Client Server (limited) Both Networking components can be added and removed as necessary Network Protocols Supported by Windows XP Major protocols: TCP/IP NWLink TCP/IP An all-embracing suite of standardized protocols (more than 50) that cover wide range of capabilities Work began in developing technology in 1969 continuing through 1970’s Became broadly available in 1981-1982 Most common networking protocols: Used by Internet for newsgroups, e-mail, file transfer, remote printing, remote booting, the World Wide Web, etc. TCP/IP Advantages Supports networking services better than the other Windows XP protocols Multiple routing protocols Good error detection and handling Works with most kinds of computers TCP/IP Disadvantages Not fast nor easy to use Mass of information and detail work Configuring and managing requires: Fair degree of expertise Careful planning Constant maintenance and attention NWLink (IPX/SPX) Microsoft implementation of Novell’s Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocol stack Provides backwards compatibility with NetWare versions 4 and earlier TCP/IP became the default protocol in version 5 Networking Under Windows XP Controlled by single multifaceted interface that combines networking access for: Local Area Network (LAN) Internet Modem Configured by running the "Network Setup Wizard" Checking Local Area Connection Properties 1. 2. Launch “Network Connections” applet from Control Panel Double-click “Local Area Connection” or other object 3. Or select object and then File Status from menu bar Reveals Connection Status, Duration, Speed, Packets Click <Properties> button Reveals NIC, all services and protocols Wireless Networking Supports IEEE 802.11 wireless standards Also known as Wi-Fi networks A single base station supports one or more clients Client must have a wireless NIC Network Setup Wizard Step-by-step, walk-through tool used to configure nondomain networks Used for small offices and home networks Can be executed from: Network Connections applet: File Network Setup Wizard –or – Start menu Programs Accessories Communications Wizard on the system to be the ICS host first Managing Bindings Binding is the order in which Windows XP networking components are linked Affects how the system behaves and system performance Accessed in "Network Connections" applet of Control Panel by selecting Advanced Advanced Settings from menu bar Advanced Settings Dialog Box— "Adapters and Bindings" Tab TCP/IP Architecture Internet Protocol (IP) Provides both addressing and routing information for source and destination systems Addresses are 4 bytes (32 bits) long Each octet between 0 and 255 Fast (although unreliable) connectionless datagram protocol which assumes that other protocols are available to assure reliable delivery IP Addresses Designates network and host (any device that is assigned an IP address) Subnet mask blocks network element: An octet value of 255 is used to block the network component of the address A value of zero does not block Class A Network ID's: 126 Host ID's: 16,777, 214 Usable network ID's: 1.x.y.z—126.a.b.c TCP/IP Protocols (Page 1) Internet Control Message Protocol (ICMP) Sends control messages including: Error messages, quality of server information, confirmations, etc. The “Ping” utility which can request response from a remote host TCP/IP Protocols Address Resolution Protocol (ARP) (Page 2) When system begins a conversation with host, requests a physical address which can be associated with the logical address Dynamic Host Configuration Protocol (DHCP) Manages a defined block of IP addresses Assigns IP addresses dynamically to computers upon request TCP/IP Protocols (Page 3) Transmission Control Protocol (TCP) Primary Internet transport protocol Connection oriented, so it provides more reliable delivery than connectionless Uses a port number to identify which process is to receive a particular packet Its sequencing function ensures that packets are reassembled in correct order Able to acknowledge successful delivery and request retransmission of lost or damaged packets TCP/IP Protocols (Page 4) Protocols within: File Transfer Protocol (FTP)—directory and file manipulation Telnet—remote terminal emulation Simple Mail Transfer Protocol (SMTP)— the basis for Internet e-mail Simple Network Management Protocol (SNMP)—reports management data Hypertext Transfer Protocol (HTTP)— the World Wide Web Some TCP/IP Utilities and Services (Page 1) Packet Internet Groper (PING) Uses ICMP protocol to see if a designated host is reachable on the network Can permit you to see if your own machine is attached properly At command line type: ping machineName ping IP_address ping 127.0.0.1 (to view your own machine) Some TCP/IP Utilities and Services (Page 2) IPCONFIG Displays the IP address, subnet mask and default gateway for all network interfaces on local machine At command line type: ipconfig [/all] NETSTAT Lists TCP/IP Configuration (Page 1) Configuration is performed through the “Network Connections” tool By default seeks out Dynamic Host Configuration Protocol (DHCP) server provides an IP address upon request Server assigns IP addresses on demand TCP/IP Configuration (Page 2) Alternately each machine may be assigned a specific IP address manually: Unique IP address for each machine Subnet mask for the network to which the machine belongs A gateway address—the node (router) on network that serves as an access point to another network In homes, the gateway is the ISP In enterprises, the gateway routes traffic from workstation to outside network TCP/IP Configuration (Page 3) Alternately each machine may be assigned a specific IP address manually (con.) Address of one or more domain name system (DNS) servers Stores and associates information with domain names providing a worldwide keyword-based redirection service Translates domain names (computer hostnames) to IP addresses Lists mail exchange servers accepting e-mail for each domain Windows XP Remote Tools Remote Assistance Allows a distant user to view your desktop Have control over the mouse and keyboard activities Remote Desktop Enables you to access your client’s logon environment from a remote system Remote Assistance Designed to simplify task of training users Requires an e-mail invitation for another machine to take over the invitee Invitation expires Both machines must be XP Windows Messenger or MAPI-compliant email utility required Uses Remote Desktop Protocol (RDP) Remote Desktop Similar to a single client version of Terminal Services Workers access work machine from home Enabled through a component of Internet Information Services (IIS) Network Setup Wizard Step-by-step, walk-through tool used to configure nondomain networks Used for small offices and home networks Can be opened from the network tasks list Wizard on the system to be the ICS host first Network Connections Window Network Connection Wizard Installing Remote Access Hardware Hardware must be installed before remote connection established Windows XP inspects hardware and attempts to identify any new devices Windows XP attempts to locate and install drivers for new device Phone and Modem Applet Primary Control Panel applet for managing remote access devices and operations Used to control: Dialing rules Configure remote access devices Configure telephony driver properties Connecting to the Internet Connect to the Internet Wizard: Choose from a list of Internet service providers (ISPs) Set up my connection manually Use the CD that I got from an ISP Connection Status Dialog Box Internet Connection Sharing Used to share single network connection with small group of networked computers Enabled on Advanced tab of connection object’s Properties dialog box Incorporates: Network Address Translation (NAT) function Dynamic Host Configuration Protocol (DHCP) address allocator Domain Name System (DNS) proxy Internet Connection Firewall Security measure for protecting network connections from unwanted traffic Can set restrictions on traffic in and out of network to an external network or the Internet Much-needed feature for systems that employ shared broadband connections Stateful firewall Blocks most incoming traffic by default Connecting to the Network at My Workplace Virtual Private Networking (VPN) Trend in mobile computing Employs Internet as long-distance carrier to enable distant, secure LAN connections Windows XP VPN: Encrypts all traffic Setup with New Connection Wizard Setting Up an Advanced Connection Used to: Establish direct connection between two systems Transfer large amount of data with no network connection Use serial or parallel cable Configure system to answer inbound dialup calls Can act as remote access server for single incoming connection Only for special-purpose applications Alternate IP Configuration Available whenever networking connection object uses DHCP Preconfigure an alternate default IP configuration if DHCP fails Found on second tab in "Internet Protocol (TCP/IP) Properties" dialog window for a Network Connection Remote Access Security Built on Windows XP local and network security Dial-up connection objects Authentication and encryption security options VPN Used to secure remote access Certificates Provide proof of identity for network and Internet communications Allow systems to trust unknown online parties for the purposes of: (Page 1) Exchanging information Exchanging Data Performing e-commerce Product of cryptographic mechanism known as public key infrastructure (PKI) Certificates (Page 2) Certificate Authority (CA): Responsible for: Creating Issuing Managing Revoking certificates Can be server computer system within organization’s network or service offered by independent third-party organization Certificates (Page 3) Found by clicking the <Certificates> button on "Content" tab of the Internet Options applet Internet Options Applet (Page 1) Used to define settings for MS Internet Explorer and general Internet access General tab to: Set the default home page Managing temporary Internet files Managing the URL history Modifying default fonts, colors, language and accessibility options Internet Options Applet (Page 2) Security tab to set security levels: The four Web zones are: 1. 2. 3. 4. Internet (not in any other zone) Local intranet (on your organization's intranet) Trusted sites (will not harm your computer) Restricted sites (may harm your computer) The <Custom Level…> options are quite complex with multiple individual settings The <Default Level> uses a slider to set security for each zone to low, medium-low, medium or high Internet Options Applet (Page 3) Privacy tab to set security levels: Sets the level personal information is or is not shared when communicating with other web sites Settings relate to how cookies are handled Either totally blocked or allowed Or accepted on some limited basis Internet Options Applet (Page 4) Content tab to configure: Content Advisor—site blocker based on levels of content Certificates—identify trusted sites AutoComplete—lists possible matches from entries the user has keyed previously into the Address bar My Profile…--your online identity Internet Options Applet Connections tab to: (Page 5) Manage your "Network Connections" Programs tab to set the default applications for: HTML editing E-mail Newsgroups Internet calling Calendar Contact list Internet Options Applet (Page 6) Advanced tab to set features such as: Accessibility Browsing functions Multimedia behaviors Printing background colors and images Searching behaviors on the Address bar Security settings Windows XP and the Internet Tools to help access the Internet: Internet Explorer Outlook Express FTP client Telnet client Internet Information Server (IIS) Internet Explorer Version 6.0 is included with XP State-of-the-art Web browser Tightly integrated with other Windows applications Wide range of security related configuration options Can be used as FTP client Outlook Express Popular e-mail client utility Part of Microsoft Office Outlook Express included in Windows XP Used to read and write e-mail Used to file and sort messages Contact management tool FTP Client Command-line implementation of FTP client included in Windows XP Used for uploading and downloading files to and from remote servers Directory services on the server (copy, rename, delete, etc.) also available Numerous freeware and shareware GUI implementations: More user-friendly I.e. WS_FTP Telnet Client Simple tool provided in Windows XP Attempts to establish Telnet session with remote system based on domain name or IP address (terminal emulation) Internet Information Server Reduced functionality version of Internet Information Server (IIS) included with Windows XP Allows system to host Web and FTP services Not designed or intended for public Web/FTP site hosting Can be used for testing server-based dynamic Web applications Limited to 10 simultaneous connections Order Prints Online Feature of the My Pictures folder Starts the Online Print Ordering Wizard Requires that Internet access be available Client Vs. Server-based Remote Access Select a Windows server (or another server-based system such as Unix or other server) for serious Internet hosting Windows XP client is limited as follows: Limited to a single incoming dial-up connection Can support only 10 simultaneous network connections Can share an Internet link with a workgroup Remote Access Troubleshooting (Page 1) Problems can be fairly elusive; check: Physical connections (phone lines, serial cables, etc.) Power to external devices Properly installed and updated drivers Properly configured settings Correct authentication credentials Similar encryption or security requirements Proper protocol requirements and settings Remote Access Troubleshooting (Page 2) Log files: File containing all communications made between OS and modem device during connection establishment Found on Diagnostics tab in Properties window of the "Modem" tab for the Phone and Modem Options applet PPP.LOG System log Found in "Event Viewer" dialog of the Administrative Tools applet Case Projects 7-1 & 8-1 (No. 1), pp. 364 & 419