IMG_1656.jpeg

# Computer Networking: Concepts, Practice Questions ## Network Concepts: Revision Questions **(i) File Transfer Overhead:** When transferring a 1KB file across a network, more than 1KB of data is transferred due to header information and error-checking mechanisms. **(ii) MAC Addresses:** MAC addr...

# Computer Networking: Concepts, Practice Questions ## Network Concepts: Revision Questions **(i) File Transfer Overhead:** When transferring a 1KB file across a network, more than 1KB of data is transferred due to header information and error-checking mechanisms. **(ii) MAC Addresses:** MAC addresses consist of hexadecimal letters (0-9, A-F). A MAC address typically has 6 groups of 2 hexadecimal characters. **(iii) MAC Address Usage:** Switches use MAC addresses to make forwarding decisions. **(iv) FTP Protocol:** The purpose of the FTP protocol is used for file transfer. **(v) Cyclic Redundancy Check (CRC):** The purpose of a Cyclic Redundancy Check (CRC) in data is error detection. **(vi) Secure Sockets Layer (SSL):** SSL adds security to HTTP connections by encrypting data. **(vii) Router and Data Headers:** When data passes through a router, the source and destination IP addresses change in the data headers. **(viii) IPv6 Address Length:** An IPv6 address has 128 bits. **(ix) Loopback Addresses:** Loopback addresses, such as 127.0.0.1 (IPv4) and ::1 (IPv6), are used for testing purposes on a local machine. **(x) MAC Broadcast Address:** The MAC broadcast address FF-FF-FF-FF-FF-FF is used for sending a message to all devices on the network. **(xi) OSI Layer for Port and Sequence Numbers:** Port numbers and sequence numbers belong to the Transport Layer in the OSI model **(xii) TCP/IP Layer for Port and Sequence Numbers:** Port numbers and sequence numbers belong in the Transport Layer of the TCP/IP model, specifically within TCP. **(xiii) OSI Layer for IPv4 Addresses:** IPv4 addresses belong in the Network Layer of the OSI model. **(xiv) TCP/IP Layer for IPv6 Addresses:** IPv6 addresses belong in the Internet Layer of the TCP/IP model. **(xv) TCP Windowing:** TCP uses windowing to manage the flow of data between devices. Windowing is important because it helps prevent network congestion, and ensures reliable delivery of data. **(xvi) Unicasting:** Sending data from one device to some of the others is called *multicasting*. **(xvii) IPv4 IP-address Class and Range:** The class and range of IPv4 IP-addresses used in multicasting are determined by their network/host bit structure. Class A, B, and C networks each have different address ranges. **(xviii) OSI Layers for Switches and Routers:** Routers operate on layers 3 (Network) and above in the OSI model, while switches operate on layers 2 (Data Link) through 7 (Application). **(xix) CRC, FCS and MD5:** CRC (Cyclic Redundancy Check), FCS (Frame Check Sequence), and MD5 are all used for error checking purposes. **(xx) ARP Protocol:** The purpose of ARP (Address Resolution Protocol) is to resolve an IP address to its corresponding MAC address.