Transcript Networking
The Basics of Networking What is networking? • Communication! • An interconnection of computers and other devices: – Printers – Servers (computers) – Scanners – Network Devices • Hubs • Switches • Routers • Firewall • Modem Rick Graziani [email protected] 2 Most successful networking applications? Rick Graziani [email protected] 3 What is in a network? Computers… Rick Graziani [email protected] 4 What is in a network? Hubs and Switches… Hub: Only one device at a time can talk. Rick Graziani [email protected] Switch: Multiple devices can talk at the same time. 5 What is in a network? Telephone Modems… Rick Graziani [email protected] 6 What is in a network? DSL and Cable Modems… Rick Graziani [email protected] 7 Extending your network and protecting yourself! Rick Graziani [email protected] 8 Connecting your DSL or Cable Modem When using NAT (Network Address Translation, the Router helps hide your network. 192.168.1.10 204.180.205.1 Rick Graziani [email protected] 9 They also allow more devices on your home network! Rick Graziani [email protected] 10 What is the Internet? • • • The Internet was originally designed by DARPA (Defense Advanced Research Projects Agency) in response to the U.S.S.R. launching Sputnik, the first satellite. Out of this came the Internet, a way for computers to communicate from different parts of the world. These computers can be any type of computer using any type of operating system, as long as they are using the protocol TCP/IP. Rick Graziani [email protected] 11 What is TCP/IP? What is a protocol? The actual letter (data) is inside (encapsulated) the envelope. • A protocol is nothing more than an agreement, a standard • way of organizing network information. The sender and receiver, and everyone in between, must agree on how this information is organized. Rick Graziani [email protected] 12 TCP/IP Transmission Control Protocol / Internet Protocol Source IP Address: 172.16.10.5 Destination IP Address 192.168.1.10 This is known as an IP Packet • TCP/IP is a suite of protocols. • IP (Internet Protocol) is used for sender and receiver addressing. • Every computer on the Internet or a network must have an IP address • • to communicate. Part of the IP address is the network address. Example: The destination address is 192.168.1.0 which includes all computers from 192.168.1.1 to 192.168.1.254. Rick Graziani [email protected] 13 What is the IP Address on my computer? Rick Graziani [email protected] 14 Pinging another computer Rick Graziani [email protected] 15 Routers • • • Routers are network devices that connect two or more networks together. Computers usually belong to a single network. Router connect multiple networks. Rick Graziani [email protected] 16 DSL Router When using NAT (Network Address Translation, the Router helps hide your network. 192.168.1.10 204.180.205.1 Rick Graziani [email protected] 17 Rick’s IP Packet Analogy… Rick Graziani [email protected] 18 Do I need to know IP Addresses? No! • Domain is a related group of networked computers: • – Cabrillo.edu – Yahoo.com – Google.com All you need to know is the domain name. Rick Graziani [email protected] 19 Domain Name Servers (DNS) Source IP address 172.16.22.73 216.109.125.69 Destination IP address • I know the Domain Name but IP uses IP addresses. • How does a Domain Name (yahoo.com) get translated to • an IP address (216.109.125.69)? Using a Domain Name Server Rick Graziani [email protected] 20 Domain Name Servers (DNS) Rick Graziani [email protected] 21 Domain Name Servers (DNS) Rick Graziani [email protected] 22 Domain Name Servers (DNS) Rick Graziani [email protected] 23 Domain Name Servers (DNS) Rick Graziani [email protected] 24 Does my computer use a DNS server? Yes! Rick Graziani [email protected] 25 Ethernet Networks • • • Most Local Area Networks (LANs) use the Ethernet protocol. Each Ethernet Network Interface Card (NIC) has an “Ethernet Address”. Yes, computers have two addresses: Ethernet Address and an IP Address Rick Graziani [email protected] 26 Ethernet Networks • So, how is an Ethernet Address used? Rick Graziani [email protected] 27 Ethernet Networks • How is the Ethernet address • • • • • used? The packet is put inside an Ethernet frame. The Ethernet source address (MAC address) is your computer. If the two computers are on the same LAN (Local Area Network) then the destination MAC address is the other computer. If the two computers are on different LANs then the destination MAC address is that of the router. Much more in CIS 81. Rick Graziani [email protected] Inside the packet Inside the Ethernet Frame Source Ethernet address Destination Ethernet address 28 Ethernet Networks • • Hubs and Switches connect Ethernet devices on the same LAN. Routers connect LANs together over WANs (Wide Area Networks). Rick Graziani [email protected] 29 WANs (Wide Area Networks) • Telecommunications companies – SBC – Quest – MCI – AT&T Rick Graziani [email protected] 30 What does an IT (Information Technology) or Networking person do? Networks are no longer a luxury, but a requirement to keep the organization running. Computer Support Specialist • • • Installing computer hardware and software. Troubleshooting Maintenance and upgrades Rick Graziani [email protected] 32 Networking: System Administrator • Installing, configuring, and maintaining network servers • UNIX, LINUX, Microsoft • Web, DNS, DHCP, Mail Servers • Backup and recovery, user administration • Security Rick Graziani [email protected] 33 Networking: Network Technician/Analyst • Install, manage, troubleshoot network infrastructure: – Routers, Switches, Cables, Wireless Access Points • Issues: Security, Quality of Service, Video On Demand, Voice over IP Rick Graziani [email protected] 34 Keeping up on technology • Wireless • Security Rick Graziani [email protected] 35 Knowing what you are doing… Rick Graziani [email protected] 36 Understanding what others do not Rick Graziani [email protected] 37