--- title: TCP Port Monitoring for Databases & Services description: Professional TCP port monitoring service by WatchFor. Monitor databases, mail servers, SSH, FTP, and custom TCP services 24/7. Track port availability and connection health, and get confirmed alerts. Free plan available. canonical: https://watchfor.io/tcp-monitoring --- # TCP Port Monitoring & Connection Health Watch the ports your databases, mail and backend services listen on, and hear about it within minutes when one stops accepting connections. [Get started for free](/auth/sign-up)[View pricing](/pricing) ## TCP Monitoring Features What the TCP monitor checks, and how it alerts you ### Port Availability Check that a host accepts connections on the port you choose. A refused, unreachable or timed-out connection fails the check, and the error is kept with it. ### Fast Detection A failed connection starts re-checks every 30 seconds from other locations, so an outage is confirmed within minutes and a single dropped connection never pages you. ### Connection Validation Go past the handshake: send a string after connecting and match the reply against a regex, for a banner check or a protocol PING. Turn on TLS to check the handshake and certificate too. ### Service Monitoring Monitor databases, mail servers, FTP, SSH, and custom TCP services. Verify that the services behind your app accept connections from the internet. ### Performance Metrics Track DNS lookup, TCP connect and TLS handshake time on every check, plus time to first byte when you send a payload. Alert when connect time crosses your threshold. ### Smart Alerting Rules for failed connections, slow connects, slow TLS handshakes and unexpected replies, each with its own severity. Alerts go to email, Slack, Discord, webhooks and more. ### Multi-Location Checks Test TCP connectivity from multiple global locations. Identify regional network issues and firewall misconfigurations. ### Historical Analysis Access detailed connection history and availability reports. Track uptime trends and identify recurring connectivity patterns. ## A closer look DNS lookup and TCP connect time for every check over the last 24 hours. Alert when the handshake slows down, confirmed over 3 failed checks. ## Why Choose Our TCP Monitoring Solution? When a database or mail server goes dark, the first sign is often a port that stops accepting connections. A TCP monitor checks that port from the locations you choose, times each stage of the connection, and confirms a failure from another location before it pages anyone. Want to test a port once? Use our free [port checker](/port-checker). [Start monitoring now](/auth/sign-up) Any TCP port from 1 to 65535 Track databases, mail servers, and custom services Validate connection establishment and handshakes Monitor from multiple global locations Track connection times and latency Detect firewall and network issues Optional send-and-match check on the reply Confirmed alerts via email, Slack, Discord, webhooks and 12 more channels ## How TCP Monitoring Works Simple setup, reliable monitoring 1 ### Add Your Service Enter the hostname or IP address and TCP port number of your service. Configure check intervals and timeout thresholds. 2 ### Configure Validation Set the timeout and connect time threshold, choose how many failed checks confirm an outage, and pick locations and notification channels. 3 ### Monitor Continuously Probe locations in the regions you chose open a connection on your interval, time each stage of it, and record the result. 4 ### Get Confirmed Alerts Once a failure is confirmed from other locations, an incident opens and you're notified. Each incident keeps its root cause and timeline. ## TCP Monitoring Use Cases Essential for any TCP-based infrastructure and services ### Database Monitoring Watch the ports of PostgreSQL, MySQL, MongoDB, Redis and other database servers. You'll know when one stops accepting connections or the network path to it breaks. A TCP check confirms the port answers; it doesn't log in or run a query. ### Mail Server Monitoring Monitor SMTP, IMAP, and POP3 ports to ensure email services remain online. Add a response match on the greeting banner to confirm the server is really speaking its protocol. For a full SMTP conversation, use the dedicated SMTP monitor. ### Backend Services Monitor custom TCP services, message brokers and internal APIs that are reachable from the internet. If they sit behind a firewall, allowlist our published probe IP ranges. For services with no public route, a heartbeat monitor, where your service pings us, is the usual answer. ### Infrastructure Monitoring Monitor SSH, FTP, SFTP, and other infrastructure services. Ensure remote access remains available and track connection health. Perfect for DevOps teams managing servers and network infrastructure. ## Frequently asked questions Everything you need to know about TCP monitoring. [All questions→](/faq)[Ask us directly](/contact) What is TCP monitoring? TCP monitoring opens a connection to a host and port on a schedule and alerts you when it's refused, times out or gets slow. It's the check for services that don't speak HTTP: databases, mail servers, SSH, message queues and your own TCP services. How does TCP port monitoring work? What services can I monitor with TCP monitoring? How often are TCP checks performed? What happens when a TCP port becomes unreachable? Can TCP monitoring detect firewall issues? What is the difference between TCP and HTTP monitoring? Can I monitor custom TCP ports? How do you handle services behind firewalls? What metrics are tracked for TCP monitoring? ## From our blog Guides, deep-dives, and best practices from the WatchFor team [Networking ### What is a Network Port? (and how to monitor one) Feb 14, 2026·3 min readRead article](/blog/what-is-a-network-port)[Networking ### ERR_CONNECTION_REFUSED: what it means and how to fix it Feb 22, 2026·3 min readRead article](/blog/connection-refused)[Networking ### TCP vs UDP: the difference, explained simply Apr 04, 2026·3 min readRead article](/blog/tcp-vs-udp) ## Ready to Start Monitoring Your TCP Services? Keep databases, mail servers and critical infrastructure under watch with external TCP checks. Get started in minutes with the free plan — no credit card required. [Get started for free](/auth/sign-up)[View documentation](/docs/monitors/network#tcp) --- Canonical page: https://watchfor.io/tcp-monitoring · Site guide: https://watchfor.io/llms.txt