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iptables firewall Application scenario 1.Host firewall 2.Internal sharing and Internet access 3.Port and ip mapping iptables workflow 1.Rule matching is performed from top to bottom 2.As long as it matches up, it doesn't match down 3.If no explicit rules are matched, the default rules will be matched (all are allowed by default and can be ...

preface Recently, I bought a month's standard example on Tencent cloud Internet of things platform and sent an ESP-12S development board to start the systematic learning of ESP8266. Therefore, I have reinstalled ubuntu several times. After thinking about it, I'd better record the ESP8266_ RTOS_ SDK_ The linux environment of V3.0 is built step ...

Reference materials: Bird brother's Linux private dishes: Basic Edition, Liu Chao's interesting talk about Linux operating system, UNIX/Linux system management technical manual, 4th Edition, in-depth understanding of Linux kernel, 3rd Edition, advanced programming in UNIX environment, 3rd Edition, Linux kernel source code scenario analys ...

1. Virtualized network Network Namespace is a function provided by Linux kernel and an important function to realize network virtualization. It can create multiple isolated network spaces with independent network stack information. Whether it is a virtual machine or a container, it seems as if it is running in an independent network. Moreo ...

1. Makefile introduction          There are countless source files in a c + + project, which are placed in several directories according to type, function and module. Makefile file defines a series of rules to specify which files need to be compiled first, which files need to be compiled later, which fil ...

How to use official SDK files to assist development 1. First of all, what is SDK? SDK or SDK package refers to a software development kit synchronously launched by semiconductor manufacturers for their own chips. It can simply provide some files of application program interface API for a programming language, but it may also include complex har ...

I/O multiplexing I/O complex method: select poll epoll effect: You can listen to multiple file descriptors at the same time, Enables the server to process multiple file descriptors at the same time without introducing multiple processes. Network programs need to use I/O multiplexing technology: ◼ The TCP server handles both listening sock ...

⭐ Configure and protect SSH Objective: to configure the secure command line service on the remote system using OpenSSH Objectives: Log in to the remote system using ssh and run the command Configure key based authentication for user accounts so that they can safely log in to the remote system without a password Restrict direct login as root ...

catalogue 1. What is a device tree? 2. Structure of equipment tree 3. Node structure 4. Node standard attributes 4.1 compatible 4.2 status 4.3 #address-cells #size-cells 4.4 reg 4.5 name 4.6 device_type 4.7 phandle 4.8 virtul-reg 4.9 range 4.10 dma-range 5. Special nodes 5.1 /aliases node 5.2 /chosen node 6."of_" cor ...

The article is reproduced for easy sorting and induction. The source address is: https://cloud.tencent.com/developer/article/1722230 When a Linux server is attacked, sometimes there are several main IP addresses. If you can reject these IP attacks, it will greatly reduce the pressure on the server, and maybe the server will return to normal. ...