LANS A Overview (also a Review)

NICS  Could be Ethernet, FDDI, Token Ring or Wireless.  Multiple Protocols can be bound to a NIC.  In WinDoze all protocols will be bound to all NICS.  A Protocol is a set of rules for communicating over a NIC.

Ethernet Cabling Options  10Base2: 10 Mbps on BNC Coax.  10Base5: 10 Mbps on AUI cable  10BaseT: 10 Mbps on Cat3/RJ45  100BaseT: 100 Mbps on Cat5/RJ45  ???BaseF?: Fiber optic

Cable Types

Coax Cable Types  RG59 Used for TV/VCR  RG6 Used for TV/VCR/Satellite Better Shielding  RG8: Thick Net Ethernet  RG58 Thin Net Ethernet

Bus Topology

Star Topology

Wireless  Access Point:

Wireless Connection Protocols  a, 5 GHz, 54Mbps, 75 feet  b, 2.4 GHz, 11 Mbps, 300 feet  g, 2.4 GHz, 54 Mbps, 50 meters  Bluetooth, 2.4 GHz, 1 Mbps, 10 meters  Wireless N 2.4 or 5.0 GHz 2.4 or 5.0 GHz Up to 600 Mbits/second Up to 600 Mbits/second Up to 150 meters (about 475 feet) Up to 150 meters (about 475 feet)

Token Ring  IBM Technology  4 or 16 Mbps  Topology: Physical-Star, Logical-Ring  Connect to a Multiple Access Unit (MAU)  MAU similar to Hub

Hubs  Physically a Star.  Uses CSMA/CD  Takes a Signal on Tx, puts it out on Rx  Logically a Bus. When one computer speaks When one computer speaks The signal goes out to All The signal goes out to All

Network Segmentation

Segmenting a Network  Decreases amount of traffic on overall network  Done through use of bridges and switches  More intelligent than hubs; make decisions about whether or not to allow traffic to pass, or where to forward that traffic  Use MAC addresses, which they store in routing tables, to determine where to send packets

Switch vs Bridge

Windows on a Network  Supports three suites of protocols TCP/IP (Transmission Control Protocol/Internet Protocol) TCP/IP (Transmission Control Protocol/Internet Protocol) Protocol suite for the InternetProtocol suite for the Internet IPX/SPX (Internetwork Packet Exchange/Sequenced Packet Exchange) IPX/SPX (Internetwork Packet Exchange/Sequenced Packet Exchange) Designed for use with Novell NetWareDesigned for use with Novell NetWare Not supported on InternetNot supported on Internet NetBEUI (NetBIOS Extended User Interface) NetBEUI (NetBIOS Extended User Interface) Proprietary Windows protocol for use on networks isolated from the InternetProprietary Windows protocol for use on networks isolated from the Internet

MAC Addresses  Unique addresses that are permanently embedded in a NIC and identify a device on a LAN  Expressed as six pairs of hexadecimal numbers and letters  A local address  Used at the lowest (physical) networking level for NICs and other devices on the same network to communicate

Ways of Assigning IP Addresses  Public, private, and reserved IP addresses  Dynamic IP addressing Dynamic Host Configuration Protocol (DHCP) Dynamic Host Configuration Protocol (DHCP)

DHCP Server

Network Address Translation  Uses a single public IP address to access the Internet on behalf of all hosts on the network using other IP addresses  Proxy server sometimes does double duty as a firewall

Proxy Server

Host Names and NetBIOS Names  Use characters rather than numbers to identify a computer on a network  Easier to remember and use than IP addresses  Two name resolution services track relationships between character-based names and IP addresses DNS (Domain Name System) tracks host names DNS (Domain Name System) tracks host names Microsoft WINS (Windows Internet Naming Service) tracks NetBIOS names Microsoft WINS (Windows Internet Naming Service) tracks NetBIOS names

Installing a Network Card and Connecting to a Network  Connecting a PC to a network requires: NIC NIC Network cable (patch cable or straight-through cable) Network cable (patch cable or straight-through cable) Device for PC to connect to (eg, a hub) Device for PC to connect to (eg, a hub)  General steps for installing and connecting Put NIC in the PC; install NIC’s drivers Put NIC in the PC; install NIC’s drivers Configure NIC using Windows, so it has appropriate addresses on the network and correct network protocols Configure NIC using Windows, so it has appropriate addresses on the network and correct network protocols Test the NIC to verify that the PC can access resources on the network Test the NIC to verify that the PC can access resources on the network

Connecting to a TCP/IP Network  Will PC use dynamic or static IP addressing?  If static addressing, what are IP address, subnet mask, and gateway for this computer?  How will DNS work? Enabled or disabled? If enabled, what are IP addresses of DNS servers?  Is proxy server used to connect to other networks? If so, what is IP address of proxy server?

NetBEUI finding Names 1. Check for NetBIOS in cache 2. If WINS server installed ask it. 3. Send a broadcast packet to all computers asking for name to MAC 4. Check LMHosts file. 5. Check HOSTS file. 6. Check DNS Server

Troubleshooting a Network Connection  Check connections in rest of network  Reboot PC and reset network connections  Make sure NIC and its drivers are installed  Check for an IRQ conflict  Check cabling and ports  Confirm most current version of motherboard BIOS  Verify you can access other resources on the remote computer

Testing TCP/IP Configuration and Connectivity  Enter Ipconfig /all at command prompt or run Winipcfg  Try loopback address test  Ping IP address of default gateway  Ping host computer you are trying to reach  If IP address works, but domain name does not work, the problem lies with DNS

Using Routers to Connect Networks

Setting up Wireless  BSS ID: Basic service set identifier, the MAC address of the Access Point.  Current Channel: 11 Channels usable in the US. Must match the Ch used by AP.  Current Tx Rate: Transmission Rate  Throughput: Data rates for Tx and Rx  Link Quality: How Good the signal is  Link Strength: How Strong the signal is.  SSID: service set ID. Used to specify AP  Tx Rate: Allows you to set the Tx Rate.  Encryption: WEP, WPA

Components used to Share Resources  Win9x:  Client for MS Network  File/Printer Sharing  Must explicitly enable file/print sharing  Win2K/XP  MSNet Client installed by default.  F/P Sharing installed by default.  Must explicitly enable file/print sharing  Must set up Sharing and Security