Vantaj

Port monitors

Port monitors open a TCP connection to a host and port, confirming the port is open and accepting connections.

How it works

  1. Vantaj attempts to open a TCP connection to host:port
  2. Waits up to 10 seconds for the connection to be accepted
  3. Records the result:
    • Up — connection established
    • Down — connection refused, timeout, or DNS failure

The monitor does not send or read any data — it only verifies the port is open.

When to use port monitors

Use port monitors to verify that a specific service is listening, without caring about the application-level protocol. Common uses:

  • Databases — PostgreSQL (5432), MySQL (3306), Redis (6379)
  • Mail servers — SMTP (25, 587), IMAP (993)
  • Game servers — any custom TCP port
  • SSH — port 22 reachability
  • Any service that doesn't speak HTTP

URL format

Enter the host and port separated by a colon:

db.example.com:5432
redis.internal:6379
10.0.0.5:22

Do not include a scheme (tcp:// is not needed).