Basic concepts of Computer network

Summary of the first chapter of《Computer Network — A Top Down Approach》

• Link layer switches are typically used in access networks, while routers are typically used in the network core.
• The IP protocol specifies the format of the packets that are sent and received among routers and end systems.
• Application layer: Message; Transport layer: Segment; Network layer: datagram; Link layer: frame.
• packet exchange and circuit exchange
• traffic intensity; throughput
• Virus are malware that require some form of user interaction to infect the users device.
• Worms are malware that can enter a device without any explicit user interaction.
• Vulnerability attack; Bandwidth flooding; Connection flooding. DoS;DDoS. IP spoofing; packet sniffer.
• Internet is a network of network.