The interview asked "the server is not responding" when the client accesses the server, how to troubleshoot the problem. How should such questions be answered?

I don't understand the basics of computer networks. Why does the TCP protocol require a three-way handshake, and how can it ensure "reliable transmission" after the three-way handshake? What does the so-called "connection" between the client and server mean? Isn't the bottom layer all a two-way transmission of data packets?

The technology that combines "dynamic token" and "key agreement" is virtual private network (VPN) technology. So what is a dynamic token? What is key agreement technology? The so-called dynamic token, the English token, can be understood as a "one-time password", expressed in English as "One Time Password", abbreviated as OTP. 

The IP addresses of the two computers are the same, but they are not on the same switch. Can they share files? The company has two computers, which are internal networks, one with an IP address of 10.1.38.100, and the other with an IP address of 10.1.38.105. In addition, the subnet mask and the default gateway are all the same. Can one of these two computers create a shared folder and the other one access it?

When the server sends data to the browser, sometimes the server sends a packet, and the browser will reply with an ACK. Sometimes the server sends three packets, and the browser responds

Q1: The router works at the IP layer and is responsible for the communication of different IP devices. The switch works at the data link layer (only the simplest switch or bridge or hub is mentioned, not the network

IPv6 is the next generation of the first generation Internet protocol IPv4, which allows users to have more IP addresses. In theory, IPv6 can allow everyone on the planet to have 16 million IP addresses, and the network speed can be increased by more than 1000 times. "

Many people can't distinguish between gateways, routers, etc. In fact, the method of identification is very simple. You only need to spend three minutes reading this article and you will understand.

The CRC32 of the Ethernet is relatively strong, but it can only guarantee that the communication on the same network segment will not be wrong (the network cables of the two machines are plugged into the same switch