Some basic network knowledge necessary for learning network security technology

In today's various cloud computing, various mobile terminals are also wide-ranging. However, various viruses and Trojans have begun to usher in another spring. Today, when 4G networks are approaching, cloud computing is becoming increasingly mature, and information technology is becoming more and more popular, network security is a long-overdue topic that people think of again.
A few days ago, abju saw a message saying that the iPhone was already popular. Abju has never done this task, and the source of the information is not reliable. I don't know what the facts are. However, it is quite possible for abju.
Today, Alibaba Cloud's computer security blog will give you a general introduction to the essential knowledge of network security technology. For reference only.
1. Understand the necessary network models.
To learn about network security, we must master the network model. This will help us to have a deep understanding of the security risks that may occur at all layers of the network model and the corresponding solutions. Among many models, we need to understand OSI, TCP/IP, Cisco, and in-depth defense network models. The first two may be familiar to you, but there may be fewer contacts between Cisco and defense in depth. After that, abju's blog will explain all the four models.
2. Understand issues related to Layer 2 (Link Layer.
Knowledge about conflict domains, broadcast domains, exchange and set lines, port security, and Spanning Tree.
3. Understand issues related to Layer 3 (Network Layer.
Includes IP routing protocols; internal routing protocols, such as r12001/v2 and OSPF; External routing protocols, such as BGP, subnetworks/supernetworks (or more precise wireless Domain Routing ); network Address Translation (NAT) and IPv6.
4. Understand issues related to the transport layer.
This layer should understand TCP and UDP, session establishment, header and related options, port address translation (PAT) and common ports.
5. Understand problems related to layer 5 to Layer 7 (Session Layer, presentation layer, and application layer.
These three layers contain application vulnerabilities, Trojan/worm/virus, content filtering, and IDS/IPS/IDP.
To learn network security, you must learn networks. To learn networks, you must master the knowledge mentioned above.

From abju's BLOG