TCP port monitoring when “HTTP 200” is the wrong signal
Some services never speak HTTP on the port you care about—databases, SSH jump hosts, or internal gateways. SitePuls ping monitors first resolve DNS, then perform a TCP connection to the host and port you configure (443 by default), with optional ICMP where your deployment enables it.
What the check actually does
The worker resolves the hostname, then opens a TCP socket to the configured port. Success means the handshake completed from SitePuls infrastructure; it does not run application-level queries unless you model those with HTTP or REST monitors separately.
How this differs from website monitoring
HTTP monitors fetch a URL and validate status, timing, and optional keywords. TCP reachability only proves the port accepts connections—useful when that is the contract you need to watch.
ICMP vs TCP in practice
Deployments may enable ICMP for legacy ping semantics, but many cloud targets block ICMP while TCP remains open. The product falls back to TCP when ICMP is unavailable—align expectations with your network policy.
Choosing the right port
Default TCP port is 443 when unspecified, mirroring common TLS endpoints. Override when you monitor non-standard services—always stay within the 1–65535 range enforced in the UI.
Alerts and incidents
Failures open incidents like other synthetic monitors. Route them through email, Telegram, or webhooks by attaching the same alert contacts you use elsewhere.
Pairing with DNS and HTTP monitors
DNS drift can make a host appear down even when the service is fine; HTTP monitors catch application regressions TCP cannot see. Combine probes when you own multiple layers.
What SitePuls does not do
No in-network agents, no packet capture, and no database query execution—only externally reachable targets you configure.
Next steps
Baseline with ping/TCP on critical ports, then add HTTP or REST monitors where user-visible behavior matters.
What you can verify with SitePuls here
- TCP/port checks target a hostname and port pair you specify.
- The checker performs a TCP connect-style reachability test from the scanning infrastructure (success/failure and timing, not application-layer parsing).
- Port checks complement HTTP or API monitors when you need socket-level reachability in addition to application checks.
- Common uses include databases, SSH bastions, game servers, or any service that should accept connections on a TCP port.
Where incident alerts can go
- Email addresses saved as alert contacts receive messages when incidents open or resolve (according to your notification settings).
- Telegram notifications via the SitePuls bot after you link a chat to an alert contact (including the bot /start flow for pending contacts).
- HTTPS webhooks that receive JSON with event type, monitor identifiers, status, timestamp, optional incident id, and a short message for generic integrations.
- Slack-compatible incoming-webhook formatting: alert contacts can use a dedicated mode so payloads match Slack-style incoming webhook expectations.
FAQ
Is this a separate monitor type from ping?
The SitePuls web UI exposes ping monitors with a TCP port field; operationally you get DNS plus TCP reachability (and ICMP when enabled server-side).
Can I monitor private RFC1918 hosts?
Only if SitePuls can reach the address over the public internet paths you expose—there is no LAN agent.
Does TCP success imply TLS is valid?
No. TLS validation belongs to SSL or HTTPS monitors; TCP only confirms the handshake at the socket layer started.
IPv6 targets?
Use hostnames or addresses your DNS resolves the same way external clients would.
How often can I poll?
Intervals follow the same plan limits as other monitor types.
Will connection pooling hide outages?
Each check opens a fresh connection—stateful middleboxes may behave differently than long-lived clients.
Combine with heartbeat monitors?
Yes—heartbeats prove scheduled jobs completed while TCP proves a service port answers.
Where do I configure it?
Create a ping-type monitor in the SitePuls app after sign-in, set the host and port, then attach alert contacts.