Articles & Guides
Useful resources for web developers and system administrators
Domains
What Is a Domain Name? Examples, Parts, Cost and How It Works
What is a domain name: real examples broken into parts, domain vs URL and hosting, extensions, cost factors, and how to find, register and check your domain.
Domains
How to Set Up a Domain: Hosting, DNS Records and Email
How to set up a domain: delegate nameservers, add A and CNAME records, handle www, point the domain to an IP and a server, configure MX and SPF, and debug TTL delays.
Networking
How to Find an IP Address: Your PC, Router and Server
How to find an IP address: public vs local, your computer on Windows, macOS and Linux, the router gateway and any server. Real ipconfig, ip a, dig and nslookup commands.
DNS
How to configure DNS: Windows, router, Android and server
How to configure DNS: change the DNS server on Windows 10 and 11, macOS, Android and your router, set domain A, CNAME, MX and NS records, then verify the result.
Networking
Static vs Dynamic IP Address: Differences, Examples, How to Check
Static vs dynamic IP explained: how DHCP leases work, whether 192.168 is static, how to check your IP type on any OS, and when a static IP is worth paying for.
Security
JWT token explained: structure, decoding, and verification
JWT token explained: header.payload.signature structure, how to decode a JWT locally or online, why decoding is not verification, classic mistakes and attacks.
Performance
HAR File: What It Is, How to Record and Its Privacy Risk
HAR file: what it is, how to record one in Chrome, Firefox, Edge and Safari, what sensitive data it holds, and how to scrub cookies and tokens before sending it.
Networking
Subnet Mask Cheat Sheet: /8–/32 Table and How to Calculate It
Subnet mask table from /8 to /32 with hosts per prefix, why 255.255.255.0 equals /24, how to find your mask on Windows, macOS and Linux, and wildcard masks.
Security
Advertising Disclosure: What Counts as an Ad and erid Basics
What counts as advertising on a website, who is responsible for the label, where the erid token goes, and which technical mistakes leave a live page unlabelled.
Monitoring
Yandex Metrica and Session Recording: Setup and Privacy
How to set up the Metrica counter and session recording: where the code goes, why recordings and goals fail, the effect on page speed, and the privacy obligations.