ss
Also written: ss -tulnp, ss -tlnp
Lists sockets. ss -tulnp shows the listening TCP and UDP ports and their programs, which is the real truth of what a server offers.
Where the book teaches it
- Chapter 1: Clients, servers and services
- Chapter 2: The web: HTTP and cookies
- Chapter 4: Web servers, reverse proxies and load balancers
- Chapter 5: Email
- Chapter 6: Directory services and LDAP
- Chapter 7: Windows domains and Kerberos
- Chapter 8: File sharing and printing
- Chapter 10: Managing network devices
- Chapter 12: What's next