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CSS Container Queries: Responsive Components by Their Own Size

PHP cURL Error 28: Find Where the Request Times Out

Verify a Downloaded File with SHA-256 on Windows and Linux

A Website Opens on Other Devices but Not One Computer

Changed PHP in cPanel but the Old Version Still Runs?

WHM Apache Status Fails While Apache Is Running: What to Check

Linux Server Performance: Measure Before Tuning

Nginx and Apache Security: Review the Whole Request Path

GitLab Updated but Still Vulnerable? The Alpine Incident and Ruby Checks

Is Logrotate Working? Check Scheduling, Rotation and the Active Log

How to Change Your IP Address: Local vs Public Image

Networking Basics How to Change Your IP Address: Local vs Public

“Change my IP” can mean changing a computer's LAN address, the router's WAN address or the exit address a website sees. These are not necessarily the ...

What Is a Network Port? TCP, UDP and Service Checks Image

Networking Basics What Is a Network Port? TCP, UDP and Service Checks

An IP address identifies the destination interface, while a transport protocol and port help identify a communication endpoint. One server can run web...

Dynamic vs Static IP Addresses: What Actually Changes? Image

Networking Basics Dynamic vs Static IP Addresses: What Actually Changes?

A dynamic IP address does not necessarily change every time a device connects. It is assigned through a mechanism and policy that may keep the same ad...

Networking Basics DNS Lookups with nslookup and dig

When inspecting DNS, record which server received which record-type query, not just the returned address. Different resolvers can have different cache...

What Is DNS? Records, Resolvers and Caching Image

Networking Basics What Is DNS? Records, Resolvers and Caching

DNS is a distributed system for records associated with domain names. Finding a website's IP address is its best-known use, but mail routing and servi...

What Is an IP Address? IPv4, IPv6 and Local Addresses Image

Networking Basics What Is an IP Address? IPv4, IPv6 and Local Addresses

An IP address is not a permanent personal identity. It identifies a source or destination in IP communication, and one device can have several address...

How to Verify a MySQL Backup After Restoring It Image

Databases How to Verify a MySQL Backup After Restoring It

A successful import message does not establish that the backup contains everything the application needs. The wrong database may have been selected, s...

MySQL Duplicate Entry 1062: Conflicts During SQL Import Image

Databases MySQL Duplicate Entry 1062: Conflicts During SQL Import

During an SQL import, ERROR 1062: Duplicate entry means a PRIMARY or UNIQUE key would be violated. It does not necessarily mean the same row appears t...

PHP and MySQL Character Encoding Problems: Diagnosing utf8mb4 Image

Databases PHP and MySQL Character Encoding Problems: Diagnosing utf8mb4

If a name such as “Çağrı” appears as garbled symbols, do not immediately run ALTER TABLE across the database. The value may have been stored incorrect...

Fixing Unknown Collation utf8mb4_0900_ai_ci During Import Image

Databases Fixing Unknown Collation utf8mb4_0900_ai_ci During Import

An SQL dump that stops with Unknown collation: 'utf8mb4_0900_ai_ci' is not necessarily damaged. The destination may not recognize the comparison rule ...

Importing Large SQL Files with phpMyAdmin: Limits and Timeouts Image

Databases Importing Large SQL Files with phpMyAdmin: Limits and Timeouts

You select an SQL backup, start the import, and receive a blank page or timeout several minutes later. Retrying immediately is tempting. However, the ...

Essential journalctl Commands for Linux Troubleshooting Image

Linux Essential journalctl Commands for Linux Troubleshooting

journalctl queries the systemd journal. When a service fails to start, narrow the search by unit, time, and priority instead of reading the entire his...