TCP port monitoring
Checking open TCP ports: SMTP, SSH, databases, game servers and any other TCP services. Just provide host:port.
Protocol
TCP
Format
host:port
Measured
Connect time
What's tracked
- Whether a TCP connection to the given port can be established.
- Handshake time (connect time) in milliseconds.
- Separate alerts for «port closed» and «port open again».
How to add
- In the bot: `/add` → choose «🔌 TCP port» → enter `host:port`.
- In the web panel: «Add monitor» → type «TCP port».
- Examples: `mail.example.com:25`, `db.internal:5432`, `game.server:27015`.
Where it's especially useful
SMTP/IMAP/POP3 (25, 465, 587, 993, 995) — monitoring mail servers.
SSH (22) — checking server availability, especially when ICMP is firewalled.
Databases (5432, 3306, 6379, 27017) and game servers (Minecraft, CS, etc.).
FAQ
Does it check only that the port is open, or the service itself?
TCP monitoring checks that the port accepts a connection and the handshake completes. The service content isn't parsed — for that use HTTP monitoring with a keyword check.
Can I check ports on non-standard addresses?
Yes. Any publicly reachable host:port is supported. Internal addresses in a private network are only monitored if you've selected Premium nodes with network access to them.