DIYTP 2009
NETWORKS AND THE INTERNET
Network Basics
 How do computers communicate?
 Network Interface Card (NIC)
 Media Access Control Address (MAC)
 Unique to each NIC
 Example: 08:00:69:02:01:FC
 Internet Protocol Address (IP)
 Identifier for a device on a network
 Domain Name Service (DNS)
 Translates Uniform Resource Locator (URL) to
specific IP address
Network Basics – How the
Internet Works
Warriors of the Net
Network Basics – Devices
 Hub
 Simplest and ‘dumbest’. Sends packets to all
connections.
 Switch
 An ‘intelligent’ hub. Only sends packets to the
port where it is supposed to go.
 Router
 Most sophisticated. Can be controlled in how it
relays packets.
Network Basics - Protocols
 Protocol
 Agreed upon method of communication.
 Many types that computers and networks use:
 Transmission Control Protocol/Internet Protocol
(TCP/IP)
 Connection-oriented
 Used for data that needs to get there
Network Basics - Protocols
Figure 1.0 – TCP/IP 3-way handshake
Network Basics – Protocols
 User Datagram Protocol (UDP)
 Connection-less
 Used when some data can be lost
Figure 1.1 – TCP vs. UDP
Network Basics – OSI Model
Figure 1.3 – OSI model
Network Basics - Utilities
 IPConfig
 Information about your Windows-based
connection
 Ping
 Sends test packet to see if another machine is
reachable
 Tracert
 ‘Ping’ + route and time to get to destination