Simple explanation
The actual command-line and hardware tools a network technician reaches for during day-to-day work and troubleshooting.
Technical explanation
- ping — tests basic Layer 3 reachability and round-trip latency.
- traceroute/tracert — shows the hop-by-hop path packets take to a destination, useful for locating where along a path a failure or slowdown occurs.
- ipconfig/ifconfig/ip — displays and manages local IP configuration (Windows/older Linux/modern Linux respectively).
- nslookup/dig — queries DNS directly, useful for diagnosing name resolution issues separately from connectivity issues.
- netstat — shows active network connections and listening ports on a local system.
- arp — displays/manages the ARP table (IP-to-MAC address mappings) on a local device.
- tcpdump/Wireshark — packet capture and analysis, for the deepest level of traffic inspection.
- Cable tester — verifies a physical cable is wired correctly and has continuity.
- Toner probe — helps physically trace a specific cable through a bundle or wall.
- Loopback adapter — tests a port/interface by looping its own signal back to itself.
- Spectrum analyzer — identifies wireless interference sources by frequency.
- NIPS/NIDS, packet sniffer — network-level monitoring and analysis tools.
- Speed test tools — measure actual achieved throughput against expected capacity.
Synonyms / related terms
| Term | Means | |---|---| | dig | Domain Information Groper — a DNS lookup tool, more detailed output than nslookup | | ARP | Address Resolution Protocol | | Toner probe | Sometimes called a "tone generator and probe kit" |
Concept Check
"A user can resolve a website's domain name to an IP address successfully, but the connection to that IP times out." This isn't a DNS problem — DNS resolution clearly succeeded. The next tool should be ping or traceroute to that specific IP, to determine whether the issue is basic reachability or occurs at a specific point along the path, not another DNS tool like nslookup/dig.
Interview-style Q&A
Q: When would you reach for traceroute instead of just ping? A: "Ping tells you whether a destination is reachable and roughly how fast, but nothing about the path in between. If ping to a destination fails or shows high latency, traceroute shows exactly which hop along the way is failing or introducing delay — critical for figuring out whether the problem is local, at an intermediate provider, or at the destination itself."
Memory trick
"Ping tells you IF, Traceroute tells you WHERE" — the core distinction between the two most-used connectivity troubleshooting tools.