Trace connectivity from your own host

By the end: Inspect interfaces and routing before blaming DNS or the remote application.

The idea

Investigate in layers: local interface, route, name resolution, transport, then application response. Different Linux systems use different network managers. A failed ICMP ping can mean filtering rather than a failed web service. Inspect settings before changing a connection, especially over SSH.

Your command toolkit

ip

What it solves: Inspect interfaces, addresses, and routes.

ip -brief address
ip route

Part of iproute2 on modern Linux. These read-only forms help distinguish an address problem from a route problem.

ifconfig

What it solves: Recognize legacy interface inspection.

ifconfig -a

Part of the older net-tools package and often absent by default. Prefer ip for new instructions while recognizing existing runbooks.

nmcli

What it solves: Inspect NetworkManager-managed devices.

nmcli device status

Reports device state when NetworkManager is present. Connection activation or edits can interrupt connectivity; the example only reads status.

nmtui

What it solves: Understand NetworkManager's text interface.

nmtui --help

The interactive interface can activate or edit connections. Explore actual changes in a local disposable environment, not your only remote connection.

ifplugstatus

What it solves: Inspect physical link detection.

ifplugstatus

An optional tool for supported interfaces. A detected cable or link does not prove internet, DNS, or application health.

ping

What it solves: Check an ICMP response with a limit.

ping -c 3 127.0.0.1

Tests your local loopback path. For remote hosts you control, responses indicate reachability at that layer, not every service's health.

traceroute

What it solves: Observe a path through network hops.

traceroute -m 5 -w 1 example.com

Bounds hop count and wait time. Missing replies may reflect filtering or rate limits, not a broken hop; paths can differ by protocol.

Before you move on

Try the guided lab below. Compare the result with the explanation, then record your reasoning in the workbook. A missing optional program or a restricted environment is something to explain, not a reason to change system settings blindly.