Articles & Guides
Useful resources for web developers and system administrators
Found 39 · Networking · Reset
Networking
How to Open Command Prompt as Admin: Methods and CMD Commands
How to open Command Prompt in Windows 10 and 11, including as administrator, plus cmd vs PowerShell and the network commands for checking a website.
Networking
How Does a Website Work? Step by Step, From URL to Page
How does a website work? Follow one request from URL to page: DNS, TCP, TLS, HTTP and rendering, the browser error each step shows, and commands to check it.
Networking
What Is a Proxy Server? How It Works, Types and Proxy vs VPN
A proxy server relays your requests and shows its own IP to sites. How HTTP, CONNECT and SOCKS5 proxies work, forward vs reverse, common ports and how to detect one.
Networking
What Is DHCP? How It Works, Setup and Fixing DHCP Errors
DHCP explained: how servers lease IP addresses (DORA, ports 67/68, renewal timers), router and Windows setup, and fixes for 'DHCP is not enabled' and 169.254.x.x.
Networking
What Is 0.0.0.0? Listen Address, Default Route and Hosts File
What 0.0.0.0 means: listen on all interfaces, the 0.0.0.0/0 default route, DHCP and hosts-file blocking. How it differs from 127.0.0.1, with ss and netstat checks.
Networking
Telnet Port Check: Test Open Ports on Windows, Linux, macOS
How to check a port with telnet: enable the Windows client, use Test-NetConnection or nc, and read refused vs timeout results. Includes a command cheat sheet.
Networking
192.168.1.1 Router Login: Find the IP, Sign In, Fix Errors
How to log in to your router at 192.168.1.1: find the real gateway IP on any OS, default logins by brand and ISP, and a fix table for when the page won't load.
Networking
ERR_FAILED (net::ERR_FAILED) in Chrome: Causes and Fixes
net::ERR_FAILED (-2) is Chrome's generic network error. The cause is usually on your side: a proxy or PAC file, an extension, antivirus, site data.
Networking
How to Test a Mail Server: SMTP, TLS, Relay and PTR
How to test a mail server: the SMTP greeting, STARTTLS support, open relay, the PTR record and blocklists. Five checks with commands and what each finding means.
Networking
ERR_TUNNEL_CONNECTION_FAILED: The Proxy Refused Your CONNECT
The tunnel is a CONNECT request to a forward proxy. Read what the proxy answers, and learn the one server-side setting that causes this for corporate users.