Servers rarely work alone. These five commands are how Linux machines talk to each other — and how you prove they can.
ping — the simplest connectivity check #
ping google.com
# 64 bytes from ... → responses are coming backA failed ping doesn’t always mean the server is down. Firewalls frequently block ICMP traffic specifically, even while HTTP, SSH, or another service on that same machine works perfectly fine. Don’t let a dead ping send you down the wrong path.
curl and wget #
Both fetch things over a URL, but they lean toward different jobs:
curl https://example.com # interact with URLs / APIs
curl http://localhost:8080 # test a local endpoint
wget https://example.com/file.zip # download a filecurl is your go-to for troubleshooting APIs and web apps; wget is your go-to when the goal is simply “get this file onto disk.”
ssh and scp — working with remote machines #
ssh alice@192.168.1.10
# connects as user 'alice' to that server — everything you type next runs remotely
scp app.zip alice@192.168.1.10:/home/alice/ # push a local file to the remote box
scp alice@192.168.1.10:/home/alice/app.log . # pull a remote file down ('.' = here)ssh is arguably the single most important command in this entire list — it’s how you actually get onto the servers you’re managing.
