Reference

Linux Commands for Network Engineers

Modern networking runs on Linux — network OSes, automation servers, cloud instances and SOC tooling. These are the 20 commands network engineers actually use daily, from ip and ss to dig, tcpdump and mtr.

The essential 20

CommandWhat it does
ip addrShow interfaces and IP addresses (replaces ifconfig)
ip routeShow the routing table (replaces route -n)
ip neighShow the ARP/neighbour table (replaces arp -a)
ping / ping6Test reachability (ICMP echo)
tracerouteShow the path packets take, hop by hop
mtrLive combined ping + traceroute — per-hop loss and latency
ss -tulnList listening TCP/UDP sockets (replaces netstat)
dig example.comQuery DNS in detail — records, TTLs, which server answered
nslookupQuick DNS lookup (simpler than dig)
curl -v https://siteTest HTTP/HTTPS from the CLI, see headers and TLS
tcpdump -i eth0Capture packets on an interface — the CLI Wireshark
ethtool eth0Show link speed, duplex and NIC details
nmcliManage NetworkManager connections (desktop/server Wi-Fi, IPs)
hostname -IShow the host's IP addresses quickly
ssh / scpRemote login and secure file copy — daily bread
nc -zv host 443Test if a TCP port answers (netcat)
systemctl status sshdCheck whether a service is running
journalctl -u sshdRead a service's logs
cat /etc/resolv.confSee which DNS servers the host uses
iptables -L / nft list rulesetView the host firewall rules

Note the modern replacements: ip replaces ifconfig/route/arp, and ss replaces netstat — the old commands still appear in tutorials but are deprecated on current distros.

The troubleshooting flow on Linux

The layered method maps directly to commands: ip addr (do I have an address?) → ip route (do I have a route?) → ping gateway → ping 8.8.8.8dig google.com (is DNS working?) → mtr (where does the path degrade?) → ss -tuln / nc -zv (is the service listening/reachable?) → tcpdump (what is actually on the wire?).

Why network engineers need Linux now

Cisco IOS-XE, automation tooling (Python, Ansible), cloud instances (AWS/Azure) and SOC platforms all assume Linux comfort. You don't need to be a sysadmin — you need these 20 commands and the confidence to read logs with journalctl.

Frequently asked questions

Which Linux commands should a network engineer know?

The core set: ip addr/route/neigh, ping, traceroute, mtr, ss, dig, nslookup, curl, tcpdump, ethtool, ssh/scp, nc, systemctl, journalctl and the resolv.conf/firewall views. These cover interface, routing, DNS, port and packet-level troubleshooting.

What replaced ifconfig and netstat?

The ip command (from iproute2) replaces ifconfig, route and arp; ss replaces netstat. The old tools are deprecated on modern distributions.

How do I check if a port is open on Linux?

Use ss -tuln to see listening sockets locally, or nc -zv host port to test a remote port from the outside.

Do I need Linux for CCNA?

The CCNA exam itself is Cisco-focused, but real jobs assume basic Linux for automation servers, cloud instances and tooling — learning these 20 commands early pays off immediately.

VS
Vipul Sir — Lead Instructor, Attila Technologies20+ years in Cisco networking. Teaching CCNA, CCNP, CCIE & CyberOps in Ahmedabad since 2004.

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