Networking Foundations¶
An IP address identifies an interface. Private addresses are routed internally; public addresses can be routed on the internet. 127.0.0.1 means “this network namespace,” not always “the physical host.”
| Term | Meaning |
|---|---|
| subnet | address range sharing a network prefix |
| gateway | next hop to other networks |
| DNS | name-to-address lookup |
| port | numbered TCP/UDP endpoint |
| listener | process waiting for connections |
Traffic normally follows DNS lookup → destination IP → TCP port → listening process. Linux tools such as ss, ip, getent, and curl make those stages observable.