💻 IT Tools & References
Subnet calculator, base converter, HTTP status codes, port reference
🌐 IP Subnet Calculator
🔢 Number Base Converter
📋 HTTP Status Codes
OK
Request succeeded
Created
Resource created successfully
No Content
Success, no body returned
Partial Content
Range request fulfilled
Moved Permanently
Resource moved, update bookmark
Found
Temporary redirect
Not Modified
Cached version is still valid
Temporary Redirect
Redirect, keep same method
Bad Request
Malformed request syntax
Unauthorized
Authentication required
Forbidden
Server refuses to authorize
Not Found
Resource does not exist
Method Not Allowed
HTTP method not supported
Request Timeout
Client took too long
Conflict
Request conflicts with current state
Gone
Resource permanently removed
Unprocessable Entity
Validation error
Too Many Requests
Rate limit exceeded
Internal Server Error
Unexpected server error
Not Implemented
Feature not supported by server
Bad Gateway
Invalid response from upstream
Service Unavailable
Server temporarily down
Gateway Timeout
Upstream server timed out
🔌 Common Port Numbers
| Port | Name | Protocol | Usage |
|---|---|---|---|
| 20 | FTP Data | TCP | File Transfer Protocol — data |
| 21 | FTP Control | TCP | File Transfer Protocol — control |
| 22 | SSH | TCP | Secure Shell remote login |
| 23 | Telnet | TCP | Unencrypted remote access (deprecated) |
| 25 | SMTP | TCP | Email sending (outbound) |
| 53 | DNS | TCP/UDP | Domain Name System lookups |
| 67 | DHCP Server | UDP | Dynamic IP assignment |
| 80 | HTTP | TCP | Unencrypted web traffic |
| 110 | POP3 | TCP | Email retrieval (older) |
| 143 | IMAP | TCP | Email retrieval (sync) |
| 194 | IRC | TCP | Internet Relay Chat |
| 443 | HTTPS | TCP | Encrypted web traffic (TLS) |
| 465 | SMTPS | TCP | Encrypted email sending |
| 587 | SMTP Sub | TCP | Email submission (STARTTLS) |
| 993 | IMAPS | TCP | Encrypted IMAP email |
| 995 | POP3S | TCP | Encrypted POP3 email |
| 1433 | MSSQL | TCP | Microsoft SQL Server |
| 3306 | MySQL | TCP | MySQL database |
| 3389 | RDP | TCP | Remote Desktop Protocol |
| 5432 | PostgreSQL | TCP | PostgreSQL database |
| 5900 | VNC | TCP | Virtual Network Computing |
| 6379 | Redis | TCP | Redis in-memory database |
| 8080 | HTTP Alt | TCP | Alternate HTTP, dev servers |
| 8443 | HTTPS Alt | TCP | Alternate HTTPS |
| 27017 | MongoDB | TCP | MongoDB database |
