How to Check if a Port Is Open (Windows, macOS & Linux)
Check if a port is open with telnet, netcat (nc), nmap, PowerShell Test-NetConnection and /dev/tcp on any OS — plus how to monitor ports continuously.
May 31, 2026
8 min read
HTTP/3 & QUIC Monitoring: What Changes and What to Watch
How HTTP/3 and QUIC change monitoring: UDP 443, 0-RTT, connection migration, fallback to HTTP/2, and the new failure modes and metrics you must watch.
May 29, 2026
9 min read
Port Monitoring: How to Check if a Server Port is Open and Responding
TCP port monitoring catches service failures that HTTP checks miss. Learn which ports to monitor and how to alert when they stop responding.
February 22, 2026
10 min read