Terminal Commands — Packet.School

GUIs change; the terminal endures. The first thing anyone troubleshooting a network opens is a command line — in this lesson you'll learn when and how to use the five essential commands, then try them in the simulator right below.

01The five essentials

Command	Answers the question	Example
`ping`	Can I reach the target?	`ping google.com`
`traceroute`	Which path am I taking, where does it stall?	`traceroute google.com`
`nslookup`	What's this name's IP? Is DNS working?	`nslookup google.com`
`ipconfig` / `ifconfig`	What are my own network settings?	`ipconfig`
`netstat`	Which connections do I have open?	`netstat -an`

ping — the connectivity test

code

ping google.com

Sends a small packet (ICMP echo) to the target and waits for a reply. Watch two things in the output: time (latency, ms) and packet loss. If ping works, your physical link and routing are sound.

traceroute — the road map

code

traceroute google.com     (on Windows: tracert)

By sending packets with increasing TTL values, it makes every router along the path identify itself. If there's a problem, it shows which hop it starts at: your home router, your ISP, or the far end?

nslookup — the DNS query

code

nslookup google.com

Tests name resolution. The classic diagnostic for "the site won't load but pinging the IP works": the problem isn't the network, it's DNS.

ipconfig / ifconfig — your own settings

code

ipconfig        (Windows)
ifconfig        (Mac/Linux)

Shows your IP address, subnet mask, and gateway. Step one of troubleshooting is always "who am I?": an IP like 169.254.x.x means you never got an address from DHCP.

netstat — open connections

code

netstat -an

Lists active connections and listening ports on your device. Use it to see which application is talking to where.

02The troubleshooting sequence

The order professionals follow for network problems:

ipconfig — do I have an IP, and is it sane?
ping 192.168.1.1 — can I reach my gateway? (local network test)
ping 8.8.8.8 — can I get out to the internet? (routing test)
nslookup google.com — do names resolve? (DNS test)
traceroute — still broken? Find out where.

These five steps diagnose 90% of "my internet is down" complaints.

03Try it now

The terminal below behaves like a real shell but runs entirely in your browser — no command touches your machine or any real network. Walk through the sequence above:

04Visual comparison

To see what the numbers in those outputs actually mean, explore ping and traceroute in visual form too:

Sandbox · CommandPing & TracerouteCompare latency, loss, and hop counts across destinations, side by side.Open tool

05Summary

ping tests reachability, traceroute the path, nslookup DNS
ipconfig shows your own settings, netstat your open connections
Troubleshooting order: your IP → gateway → internet → DNS → path

01The five essentials

Command	Answers the question	Example
`ping`	Can I reach the target?	`ping google.com`
`traceroute`	Which path am I taking, where does it stall?	`traceroute google.com`
`nslookup`	What's this name's IP? Is DNS working?	`nslookup google.com`
`ipconfig` / `ifconfig`	What are my own network settings?	`ipconfig`
`netstat`	Which connections do I have open?	`netstat -an`

ping — the connectivity test

code

ping google.com

traceroute — the road map

code

traceroute google.com     (on Windows: tracert)

By sending packets with increasing TTL values, it makes every router along the path identify itself. If there's a problem, it shows which hop it starts at: your home router, your ISP, or the far end?

nslookup — the DNS query

code

nslookup google.com

Tests name resolution. The classic diagnostic for "the site won't load but pinging the IP works": the problem isn't the network, it's DNS.

ipconfig / ifconfig — your own settings

code

ipconfig        (Windows)
ifconfig        (Mac/Linux)

Shows your IP address, subnet mask, and gateway. Step one of troubleshooting is always "who am I?": an IP like 169.254.x.x means you never got an address from DHCP.

netstat — open connections

code

netstat -an

Lists active connections and listening ports on your device. Use it to see which application is talking to where.

02The troubleshooting sequence

The order professionals follow for network problems:

ipconfig — do I have an IP, and is it sane?
ping 192.168.1.1 — can I reach my gateway? (local network test)
ping 8.8.8.8 — can I get out to the internet? (routing test)
nslookup google.com — do names resolve? (DNS test)
traceroute — still broken? Find out where.

These five steps diagnose 90% of "my internet is down" complaints.

03Try it now

The terminal below behaves like a real shell but runs entirely in your browser — no command touches your machine or any real network. Walk through the sequence above:

04Visual comparison

To see what the numbers in those outputs actually mean, explore ping and traceroute in visual form too:

Sandbox · CommandPing & TracerouteCompare latency, loss, and hop counts across destinations, side by side.Open tool

05Summary

ping tests reachability, traceroute the path, nslookup DNS
ipconfig shows your own settings, netstat your open connections
Troubleshooting order: your IP → gateway → internet → DNS → path