Uptimeify

TCP

TCP (Transmission Control Protocol) is the connection-oriented protocol that opens a reliable link between a client and a specific port on a server before any application data is exchanged.

Every TCP connection targets a numbered port, for example port 22 for SSH or port 443 for HTTPS, and only succeeds if something is listening there and completes the three-way handshake.

A successful TCP connection only proves the port is reachable; it says nothing about the protocol running on top of it, which is why a TLS handshake or an SSH login can still fail even after the underlying TCP connection succeeds.

Monitor every port your service runs on

Uptimeify opens a TCP connection to your database, cache or API on a schedule and alerts you the moment the port stops answering.

Start TCP port monitoring

Free for 14 days

Just need a quick look? Run a free port check

Related terms

SSHSSH (Secure Shell) is an encrypted protocol for securely logging into and administering remote servers.FTP / FTPSFTP (File Transfer Protocol) and its secure variant FTPS move files between systems, commonly for deployments, backups, and data exchange.TLS HandshakeThe TLS handshake is the negotiation at the start of an HTTPS connection where client and server agree on encryption and the server proves its identity with a certificate.
Set Uptimeify as a preferred source on Google

Google shows sources you mark as preferred more often in its answers.

Start monitoring in minutes

EU-hosted uptime monitoring with multi-location confirmation that kills false alarms, white-label for agencies.

Start Free TrialBook a Call