15. Networking Concepts Flashcards
What is a network?
2 or more computers linked together to share data
What are network clients?
Computers & software that request resources from servers
Purpose of network protocols?
assign unique addresses to hosts & define packet structures for communication
What is a packet?
A wrapper for network data units
What do packets generally consist of?
- Header
- Payload
Header = protocol type, source address, destination address, erorr correction information, etc.
Payload = Data
What does network encapsulation mean?
A packet from 1 protocol can be wrapped within the packet from another
Primary protocol of the Internet & WWW?
TCP/IP
TCP/IP is also the primary porotocol for many private internets (networks that connect LANs together)
What is TCP/IP?
Suite of network transport protocols
TCP/IP layers?
- Application
- Transport
- Internet
- Link
These layers work together to enable communication between devices over a network, with each layer handling specific tasks and responsibilities.
What does the link layer do?
Puts frames onto the physical network.
At this layer, various networking technologies like Ethernet or Wi-Fi are used for local communication. Data is packaged into frames, but TCP/IP protocols are not utilized, and communication is limited to the local network segment.
What do the Internet layer protocols do?
Encapsulates packets into datagrams & handles routing between networks
3 protocols used in the Internet layer?
- IP
- ARP
- ICMP
Meaning of ARP?
Address Resolution Protocol
Meaning of ICMP?
Internet Control Message Protocol
TCP’s Internet layer protocols
What does the IP protocol do?
Facilitates logical addressing & packet routing
TCP’s Internet layer protocols
What does the ARP protocol do?
Maps MAC addresses to IP addresses
This makes it possible for packet delivery
Hosts broadcast ARP messages onto the local network to find out which host MAC address “owns” a particular IP address. If the destination host responds, the frame can be delivered. Hosts also cache IP:MAC address mappings for several minutes to reduce the number of ARP messages that have to be sent.