Networking Tools

Everyday Network Troubleshooting: Tools You Should Know (and Actually Use)

Whether you’re debugging why a pod can’t reach an endpoint or trying to figure out why your app’s requests are timing out, networking tools are your first line of defense.

Here’s a curated, opinionated, and battle-tested list of tools I use (almost) daily. Each one comes with practical examples.

Connectivity & Reachability

ping

Checks if a host is alive using ICMP echo requests.

ping google.com
ping -c 4 192.168.1.1 # -c 4 is to send 4 packets

Tip: If ping doesn’t work, the host could be up but blocking ICMP. Check firewall rules.

traceroute

Visualise the path packets take to a remote host. Great for pinpointing bottlenecks.

traceroute google.com
traceroute -I 192.168.1.1 # -I is to use ICMP echo requests

Use case: “Why is latency high between service A and B?” → traceroute.

nslookup

Simple tool for querying DNS. Quick and dirty.

nslookup google.com
nslookup 8.8.8.8

dig

More verbose and powerful DNS query tool than nslookup.

dig google.com
dig google.com ANY # ANY is to get all records
dig google.com A +short # A is to get A records
dig google.com AAAA +short # AAAA is to get AAAA records

Bonus: Use +trace to debug DNS resolution path:

dig +trace google.com
dig +trace google.com +short # +short is to get the IP address

Port Scanning & TCP Checks

netcat (nc)

The Swiss Army Knife of TCP/UDP.

nc -zv google.com 80
nc -l 1234  # Listen on port 1234
nc -zv 192.168.1.1 1-65535 # -z is to scan all ports

Tip: nc can be used to spin up fake HTTP servers or test port exposure in firewalled networks.

telnet

Old school, but works.

telnet google.com 80

Can be used to debug HTTP, SMTP, Redis manually.

Interface & Routing Info

ip (modern)

ip addr show
ip route show
ip link set eth0 up

ifconfig (legacy but familiar)

ifconfig
ifconfig eth0 up

route (macOS)

route -n
route add default gw 192.168.1.1

Monitoring Traffic & Usage

netstat

netstat -an
netstat -r

ss (modern netstat replacement)

ss -tuln
ss -s

tcpdump

Capture packets like a boss.

tcpdump -i eth0
tcpdump -i eth0 -w capture.pcap

Tip: Combine with wireshark to visualize packets.

tshark

CLI version of Wireshark.

tshark -i eth0
tshark -r capture.pcap

vnstat

Track bandwidth usage.

vnstat -l
vnstat -d

nload / nethogs

Real-time network I/O monitor per interface or per process.

nload
nethogs

Wireless Tools

iw
iwlist
iwconfig

These are useful on laptops, Raspberry Pi setups, or Linux wireless APs.

Security, Scanning & Recon

nmap

Port scanner and network mapper.

nmap google.com
nmap -sP 192.168.1.0/24

Pro tip: Use with -A for OS detection, versioning, script scanning.

whois

Lookup domain ownership.

whois google.com

lsof

See what ports your system is listening on.

lsof -i :80
lsof -i tcp

arp / arping

arp -a
arp -d 192.168.1.1

arping 192.168.1.1

Use for static IP-to-MAC mapping debugging or LAN sniffing.

Bandwidth Testing

iperf

Client-server bandwidth tester.

iperf -s          # Start server
iperf -c <ip>     # Run client against server

Works great for diagnosing slow internal links or tunnels.

mtr

Combines ping + traceroute with live stats.

mtr google.com
mtr google.com
mtr -r google.com

Instant visibility into jitter, loss, and latency by hop.

Bonus Mentions

conntrack – Show conntrack entries
ssdp – Debug multicast/UPnP
ncdu – Disk usage but worth knowing if you're debugging slow apps
hostname – Quick check or change the hostname

My Top 5 Daily Use Tools

Purpose	Tool
Ping test	ping
DNS Resolution	dig
Port connectivity	nc / telnet
Interface info	ip addr
Live traffic debug	tcpdump

Final Thoughts

These tools are deceptively simple—but when chained together, they help you uncover:

• Firewall misconfigurations
• DNS issues
• Interface problems
• Packet loss/jitter
• Port blocks or misroutes
• Host reachability vs app-level downtime

Bookmark this. Refer to it next time you’re troubleshooting networking issues.