TCP Ping Test

TCP Ping validates whether a host accepts TCP connections on a specified port. It is useful when ICMP is filtered and you need practical reachability evidence for real services.

What this tool checks

• Connection success/failure over configurable attempt windows.
• Latency signals for transport-level responsiveness.
• Outcome patterns useful for firewall and path troubleshooting.

How to read the output

• Result Summary indicates whether target TCP reachability is stable.
• Overview helps identify intermittent vs. consistent failure quickly.
• Technical Details should be reviewed for timing and refusal behavior.
• Raw Output supports incident notes and escalation artifacts.

Common failure patterns

1. SYN timeouts due to ACL, security group, or upstream filtering.
2. Port open in one region but blocked in another path segment.
3. Intermittent resets indicating overloaded edge or policy churn.
4. Wrong port assumption leading to false “host down” conclusions.

Remediation workflow

1. Verify service listens on intended port and interface.
2. Confirm network policy on host, VPC, and perimeter layers.
3. Compare behavior from different networks to isolate path controls.
4. Follow with traceroute when failures remain location-dependent.

Next steps

• Traceroute (Phase 2)
• HTTP Response Header Viewer
• Back to Network category

FAQ

Why use TCP ping instead of ICMP ping?

TCP ping maps closer to real service availability when ICMP is blocked or deprioritized.

Does successful TCP ping guarantee app health?

No. It proves transport reachability, not full application correctness.

Can latency spikes predict incidents?

They often indicate capacity pressure or path instability worth proactive review.

Should I increase attempts during packet loss?

Yes, but keep windows bounded and compare with traceroute for root-cause clarity.

What is the best next step after TCP failure?

Inspect policy layers and run traceroute to locate likely breakpoints.