There are more and more people who want to learn operation and maintenance. What are the necessary skills for operation and maintenance in the learning process? What problems will you encounter during the interview? Agreement-related knowledge, what are the interview points?
1 Choose
1.1 The ports of the mail server smtp and pop3 are respectively
43 110 25 143
110 25 25 110
1.2 Among the following network protocols, the connection-oriented protocol is ()
A: Transmission Control Protocol B: User Datagram Protocol
C: Internet Protocol D: Internet Control Message Protocol
1.3 The correct use of tcpdump below is ()
A.tcpdump-p ip port 80 B.tcpdump-p tcp port 80
C.tcpdump-p port 80 tcp D.tcpdump ipaddr 192.168.13.33
1.4 What protocols are used by default for traceroute under Linux and tracert under windows?
TCP&ICMP UDP&TCP
UDP&ICMP ICMP&ICMP
1.5 Please match the following network protocols with traditional ports (connection)
SMTP TCP/23
FTP TCP/25
SQLNET TCP/22
TFTP TCP/80
Telnet TCP/21
HTTP UDP/69
DNS TCP/53
SSH TCP/1521
1.6 Which of the following protocols are network layer protocols
HTTPS ICMP SSL SNMP
1.7 In the process of a tcp three-way handshake, at least a few syn packets must be sent
1 2 3 It depends on the specific situation
1.8 Which of the following protocols does the TCP/IP protocol belong to: ()
File Transfer Protocol File Storage Protocol
Transmission Control Protocol Hypertext Transfer Protocol
1.9 Protocols used internally in the IPSAN network architecture: ()
CIFS ISCSI FCSCSI FTP
1.10 If the real-time requirements of the data are relatively high, but the accuracy requirements of the data are relatively low (such as online movies), the _ protocol can generally be adopted at the transport layer: ()
UDP TCP FTP IP
1.11 When troubleshooting a network connection problem, it was found that the NIC of the workstation and the link status of the switch port of the workstation were all on. But when I send a ping command from the workstation, the output is "request timeout". Which layer of the OSI model is most likely to be faulty?
Session layer protocol layer data link layer access layer network layer
1.12 Some of the following protocols are not transmitted in plain text.
telnet ftp ssh http smtp pop3 sftp https
2 fill in the blanks
2.1 dns uses () protocol, http uses () protocol. Ftp uses () protocol, smtp uses () protocol.
2.2 When there is no condition to establish a DNS server in the LAN, but you want to allow users in the LAN to access each other using computer names, you should configure _.
2.3 The mail is sent through the agreement, and the mail is received through the agreement.
2.4 The TCP/IP protocol used internally in the IPSAN network architecture ()
2.5 In the TCP protocol, the port number is used to distinguish different application processes ()
2.6 The speed of TCP protocol transmission data packet is generally slower than UDP protocol transmission speed ()
2.7 In TCP/IP, the difference between layer and layer is the most critical; __ layer provides point-to-point services, while layer provides end-to-end services
2.8 Three modes of VIP agreement;_;__
3 short answer
3.1 How to use the tcpdump command to sniff data packets whose source address is 112.222.16.25 and whose destination port is port 80 (write specific commands)
3.2 Use tcpdump to monitor the data whose host IP is 192.168.1.3 and tcp port is 3306, and write the corresponding commands.
3.3 Please list the osi seven-layer model. Do you know what protocols correspond to each layer?
3.4 Describe the four waves of the TCP three-way handshake process and the state of the client and server during each process.
3.5 Use tcpdump to capture Linux data packets, it is required to capture data packets with ip 202.108.1.20 and port 80
3.6 Draw a diagram showing the TCP packet encapsulation sequence and four waved hand diagrams: Please draw a diagram of the TCP/IP state machine migration (additional items can be drawn on the back)
3.7 Please explain the detailed process of a network request based on the TCP/IP protocol?
3.8 OS1 Open System Interconnection Basic Reference Model and TCP/IP Protocol Architecture
3.9 osi seven-layer model, tcp three-way handshake process, tcp connection disconnection process, when TCP enters TIME_WAIT
3.10 What is ARP (Addre***esolutionProtocol) address resolution protocol
3.11 Can UDP be sent across network segments? What are the requirements?
3.12 Briefly describe the working principle of the ARP protocol
3.13 What protocol is used to convert MAC and IP?
3.14 What protocol is ARP? What are the types? What are the roles?
3.15 OSI reference model and functions
3.16 Please list what each layer of the OSI seven-layer model is. And answer which layer tcp works on
3.17 The router works at the layer of the OSI model. What are the common routing protocols?
3.18 What are the ISO/OSI 7-layer models?
3.19 Briefly describe the OSI network hierarchy reference model. Which layer is the MAC address? What role does it play?
3.20 Briefly describe the difference between TCP and UDP
3.21 Found that there are a large number of TIME_WAIT in the system, analyze the reason and put forward three or more optimization suggestions.
Transfer from: https://www.oldboyedu.com/blog/1912.html