Ports and networking tools
On This Lesson 4 topics
This lesson is planned. The outline below lists the topics it will cover. The full lesson has not been published yet.
In this lesson
find which process listens on a port.
Planned topics
- A port is a numbered door on a machine; one process can listen on a port at a time.
ss -tlnplists listening TCP ports with the process (may needsudo).lsof -i :8080shows what uses port 8080.curl -v localhost:8080/actuator/healthtests an endpoint.- "Address already in use" means another process holds the port.
Draft outline details
Demonstration
ss -tlnp | grep 8080
lsof -i :8080
curl -i localhost:8080/actuator/healthCheck your understanding
What does "Address already in use" mean?
Show answer
Another process is already listening on that port.
Practice
Apply this lesson with the module's lab, exercises and quiz.
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