Operation and MaintenanceLinux Operation and MaintenanceHow to check whether a specified port is open in Linux
First we open the command operation interface of Linux where we want to view the port, as shown in the figure (taking Ubuntu system as an example)
Then in order to obtain higher permissions (view all ports), switch to root user login here
The first method is to use lsof -i:port No. command line, taking 80 as an example, as shown in the figure:
Recommended related video tutorials: linux video tutorial
If there is no output, it means that the port number is not enabled. To facilitate testing, I will detect an open port number here, and the information as shown in the figure will be output
The second method is to use the netstat -aptn command line to view all open port numbers.
The command shown in the picture is to view all open port numbers in the system. Port number using udp protocol
Then this command is to view the port number information using tcp protocol in the system
Recommended related articles and tutorials: linux tutorial
The above is the detailed content of How to check whether a specified port is open in Linux. For more information, please follow other related articles on the PHP Chinese website!
Understanding Linux's Maintenance Mode: The EssentialsApr 14, 2025 am 12:04 AMLinux maintenance mode is entered by adding init=/bin/bash or single parameters at startup. 1. Enter maintenance mode: Edit the GRUB menu and add startup parameters. 2. Remount the file system to read and write mode: mount-oremount,rw/. 3. Repair the file system: Use the fsck command, such as fsck/dev/sda1. 4. Back up the data and operate with caution to avoid data loss.
How Debian improves Hadoop data processing speedApr 13, 2025 am 11:54 AMThis article discusses how to improve Hadoop data processing efficiency on Debian systems. Optimization strategies cover hardware upgrades, operating system parameter adjustments, Hadoop configuration modifications, and the use of efficient algorithms and tools. 1. Hardware resource strengthening ensures that all nodes have consistent hardware configurations, especially paying attention to CPU, memory and network equipment performance. Choosing high-performance hardware components is essential to improve overall processing speed. 2. Operating system tunes file descriptors and network connections: Modify the /etc/security/limits.conf file to increase the upper limit of file descriptors and network connections allowed to be opened at the same time by the system. JVM parameter adjustment: Adjust in hadoop-env.sh file
How to learn Debian syslogApr 13, 2025 am 11:51 AMThis guide will guide you to learn how to use Syslog in Debian systems. Syslog is a key service in Linux systems for logging system and application log messages. It helps administrators monitor and analyze system activity to quickly identify and resolve problems. 1. Basic knowledge of Syslog The core functions of Syslog include: centrally collecting and managing log messages; supporting multiple log output formats and target locations (such as files or networks); providing real-time log viewing and filtering functions. 2. Install and configure Syslog (using Rsyslog) The Debian system uses Rsyslog by default. You can install it with the following command: sudoaptupdatesud
How to choose Hadoop version in DebianApr 13, 2025 am 11:48 AMWhen choosing a Hadoop version suitable for Debian system, the following key factors need to be considered: 1. Stability and long-term support: For users who pursue stability and security, it is recommended to choose a Debian stable version, such as Debian11 (Bullseye). This version has been fully tested and has a support cycle of up to five years, which can ensure the stable operation of the system. 2. Package update speed: If you need to use the latest Hadoop features and features, you can consider Debian's unstable version (Sid). However, it should be noted that unstable versions may have compatibility issues and stability risks. 3. Community support and resources: Debian has huge community support, which can provide rich documentation and
TigerVNC share file method on DebianApr 13, 2025 am 11:45 AMThis article describes how to use TigerVNC to share files on Debian systems. You need to install the TigerVNC server first and then configure it. 1. Install the TigerVNC server and open the terminal. Update the software package list: sudoaptupdate to install TigerVNC server: sudoaptinstalltigervnc-standalone-servertigervnc-common 2. Configure TigerVNC server to set VNC server password: vncpasswd Start VNC server: vncserver:1-localhostno
Debian mail server firewall configuration tipsApr 13, 2025 am 11:42 AMConfiguring a Debian mail server's firewall is an important step in ensuring server security. The following are several commonly used firewall configuration methods, including the use of iptables and firewalld. Use iptables to configure firewall to install iptables (if not already installed): sudoapt-getupdatesudoapt-getinstalliptablesView current iptables rules: sudoiptables-L configuration
Debian mail server SSL certificate installation methodApr 13, 2025 am 11:39 AMThe steps to install an SSL certificate on the Debian mail server are as follows: 1. Install the OpenSSL toolkit First, make sure that the OpenSSL toolkit is already installed on your system. If not installed, you can use the following command to install: sudoapt-getupdatesudoapt-getinstallopenssl2. Generate private key and certificate request Next, use OpenSSL to generate a 2048-bit RSA private key and a certificate request (CSR): openss
Debian mail server virtual host configuration methodApr 13, 2025 am 11:36 AMConfiguring a virtual host for mail servers on a Debian system usually involves installing and configuring mail server software (such as Postfix, Exim, etc.) rather than Apache HTTPServer, because Apache is mainly used for web server functions. The following are the basic steps for configuring a mail server virtual host: Install Postfix Mail Server Update System Package: sudoaptupdatesudoaptupgrade Install Postfix: sudoapt
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.
SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
