computer network fundamentals

Computer Network Fundamentals CS 1 Rick Graziani Cabrillo College Rick Graziani graziani@cabrillo.edu 2 What is networking? • Communication! • An interconnection of computers and other devices including: – Client computers – Servers (computers) – Network Devices • Hubs and Switches • Routers • Firewall Rick Graziani graziani@cabrillo.edu 3 Most successful networking applications? Rick Graziani graziani@cabrillo.edu 4 What is in a network? Rick Graziani graziani@cabrillo.edu 5 What is a network? • A computer network is a series of computers and other devices interconnected by communication paths. • Computer networks include: LANs and WANs http://www.albany.edu Rick Graziani graziani@cabrillo.edu 6 Ethernet LANs Rick Graziani graziani@cabrillo.edu 7 LAN – Local Area Network • LAN (Local Area Network) - A network connecting computers at a single site Rick Graziani graziani@cabrillo.edu 8 LAN – Local Area Network • A LAN: – Operates within a limited geographical area – Controlled by local administration – Allows local users to: • Share printers • Access local file servers with software and data • Access the Internet Rick Graziani graziani@cabrillo.edu 9 Ethernet LANs • The most common LAN technology is Ethernet. • Ethernet allows computers, printers, and other devices, “in the same network”, to be able to communicate. • For devices to be able to communicate with each other over an Ethernet network, they must be configured with: – IP Address and Subnet Mask on the same network – What??? (We will discuss this shortly) Rick Graziani graziani@cabrillo.edu 10 Creating an Ethernet Network • To start, your computer must have an Ethernet Network Interface Card (NIC). • Ethernet NICs have an RJ-45 interface or port. [...]... To communicate with other • • • • I am part of the 192.168.1.0 network! computers on your network you need to properly configure: – IP Address (of your computer) – Subnet Mask (of your computer) IP – Internet Protocol IP Address is the unique address of your computer on your network Subnet Mask is used by your computer to figure out what network it belongs to Analogy: – Name: RICKGRAZIANI – Mask: FFFFLLLLLLLL... graziani@cabrillo.edu 12 Creating an Ethernet Network Rick Graziani graziani@cabrillo.edu 13 Configuring IP (Internet Protocol) Rick Graziani graziani@cabrillo.edu 14 IP Configuration • • • To communicate with other computers on your network you need to properly configure: – IP Address (of your computer) – Subnet Mask (of your computer) To communicate with computers outside your network you need to properly configure:... could use IP Addresses when accessing other computers, but we would rather use names (domain names) Rick Graziani graziani@cabrillo.edu 21 IP Configuration: DNS • • • • Computer networks only understand IP Addresses such as: – 66.94.230.47 Computer networks do not understand domain names such as: – www.yahoo.com – A domain name is a name that is entered into a computer (e.g as part of a website or other...Creating an Ethernet Network • Hubs and Switches are used to connect computers, printers and other devices in the Ethernet LAN Rick Graziani graziani@cabrillo.edu 11 Creating an Ethernet Network • Ethernet cables, i.e Cat-5 or Cat-6 cables (Category 5, Category 6) are used to connect computers to the hubs and switches • Cat-5 cable connects computer NIC to hub or switch Rick Graziani... graziani@cabrillo.edu 16 IP Configuration: Default Gateway • To communicate with computers outside your network you need to properly configure: – Default Gateway IP Address Rick Graziani graziani@cabrillo.edu 17 IP Configuration: Default Gateway • Default Gateway or Router: This is the device that connects your network to other networks, including the Internet DSL or Cable Modem port that connects to your... Rick Graziani graziani@cabrillo.edu 24 How do I view/edit this information on my computer? Rick Graziani graziani@cabrillo.edu 25 How do I view/edit this information on my computer? 3 TCP/IP, Properties Left click 1 Right click 2 Right click Rick Graziani graziani@cabrillo.edu 26 How do I view/edit this information on my computer? Rick Graziani graziani@cabrillo.edu 27 Setting the IP Configuration Information... 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 graziani@cabrillo.edu 33 What is TCP/IP? What is... DSL or Cable Modem port that connects to your Internet Service Provider Rick Graziani graziani@cabrillo.edu Switch ports that connect to computers on your LAN 18 IP Configuration: Default Gateway • Any information that needs to be sent to IP Addresses outside your network is sent to the Default Gateway or Router To the Internet 192.168.1.10 192.168.1.1 Rick Graziani graziani@cabrillo.edu 19 IP Configuration:... and then looked up in the global [Domain Name System] which informs the computer of the IP address(es) with that name (Wikipedia.com) People are better with names than numbers, so we would rather use names when: – Accessing a web page: www.yahoo.com – Emailing a friend: Rick.Graziani@cabrillo.edu DNS (Domain Name System) servers (computers) are used to translate domain names to IP Addresses Rick Graziani... 192.168.1.10 Destination IP Address 66.94.230.47 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 Rick Graziani graziani@cabrillo.edu 36 . in a network? Rick Graziani graziani@cabrillo.edu 5 What is a network? • A computer network is a series of computers and other devices interconnected by communication paths. • Computer networks. with other computers on your network you need to properly configure: – IP Address (of your computer) – Subnet Mask (of your computer) • To communicate with computers outside your network you. graziani@cabrillo.edu 7 LAN – Local Area Network • LAN (Local Area Network) - A network connecting computers at a single site Rick Graziani graziani@cabrillo.edu 8 LAN – Local Area Network • A LAN: – Operates