• What are the four-tier agents and seven tier agents talking about?


    In daily communication or reading articles with leaders, we will always encounter two concepts “four-tier agent load balancing” and “seven tier agent load balancing”. Then, what do the so-called four tier agent and seven tier agent refer to respectively? In what scenario? This article will take you to talk about this knowledge. OSI seven layer […]

  • Going deep into http / 3 (1) | looking at the evolution of the protocol from the establishment and closure of quic links


    Text | Zeng Ke (flower name: Yisi) Senior engineer of ant group Be responsible for the construction of access layer of ant groupThe main direction is the design and optimization of high-performance secure network protocol This article reads 10279 words for 18 minutes PART. 1 Introduction As the first article in this series, the introduction […]

  • Wide area network protocols HDLC and PPP for hcna Routing & Switching


    In the previous article, we learned about the topics related to address translation technology NAT. For review, please refer tohttps://www.cnblogs.com/qiuhom-1874/p/15168042.html; Today, let’s talk about two layer-2 encapsulation protocols HDLC and PPP in Wan; What is Wan? Wide area network (WAN); It is a collection of large and regional computer networks. Usually across provinces, cities, or […]

  • 20211907 Liu Changhe 2021-2022-2 the fourth operation of network attack and defense practice


    Experimental principleARP spoofing attack: ARP is an early network protocol, and rfc826 was published in 1980. The early Internet adopted the trust model, which was used in scientific research and universities. It pursued function and speed without considering network security. ARP spoofing is to illegally claim that it is the MAC address of an IP […]

  • PPPoE protocol of hcna Routing & Switching


    Previously, we learned about the topics related to HDLC and PPP protocols in Wan. For review, please refer tohttps://www.cnblogs.com/qiuhom-1874/p/15174240.html; Today, let’s talk about PPPoE protocol related topics; Digital subscriber line (DSL) is a transmission technology with telephone line as the transmission medium. We usually call all DSL technologies xDSL, and X represents different kinds of […]

  • Python socket programmer simulates HTTP get request and response


    preface The get request message consists of: Start line Request headers HTTP headers Empty line Three parts Because it is a get request, there is no request body The get response message consists of: Status line start line Response headers HTTP headers Empty line Response body Four parts Use between each part\r\nseparate Reference article:Mozilla doc: […]

  • 1.5W words + 24 pictures.


    TCP is a connection orientedunicastProtocol. In TCP, there is no such behavior as multicast and broadcasting, because the IP addresses of the sender and receiver can be defined in the TCP message segment. Before sending data, both parties communicating with each other (i.e. sender and receiver) need to establish aconnect, after sending data, the communication […]

  • API service interface signature code and design, if your interface does not take SSL?


    Before reading the following article, let’s ask a few questions Why do rest services need signatures? How many ways to sign? I think it’s a convenient and fast way to sign (if there are great gods who disagree, you can communicate!)? How to realize the signature verification process? How to design the open API sign […]

  • Programming life


    Some time ago, I saw the “little works of imperial gifts”, which has many details and is very attentive. After reading some comments, they are: finally, we can see normal people who are really engaged in business and pay back the money at the first time. What impresses me deeply is the grapes that can […]

  • TCP / IP optimization


    1. Optimization objectives Reduce network congestion. Is it always effective? No, they have specific usage scenarios. 2 Nagle algorithm and delayed ack algorithm In TCP / IP protocol, every message is composed of a header and a payload. Just like the book we bought online, the book is packed in a bag and then pasted […]

  • IS-IS message structure and type of HCNP Routing & Switching


    Previously, we learned about the basic topics of IS-IS dynamic routing protocol. For review, please refer tohttps://www.cnblogs.com/qiuhom-1874/p/15249328.html; Today, let’s talk about the message structure and type of IS-IS dynamic routing protocol; IS-IS message structure Tip: IS-IS dynamic routing protocol is encapsulated on the data link layer and mainly consists of IS-IS header and IS-IS variable […]

  • Skills of NSQ consumers in dealing with graceful shutdown


    Original text from: 〔Skills of NSQ consumers in dealing with graceful shutdown』 NSQIt is a real-time decentralized message processing platform, which aims to provide a large number of message transmission. The team can design a decentralized architecture according to different tasks to digest a large number of messages. And I recently developed an open source […]