Basic Networking Commands on Linux

Why these Linux networking commands matter

When a website or server appears “down”, the real issue might be very different from what it first looks like. You may need to confirm the hostname, check IP addresses, test DNS, see whether a service is listening on the right port or confirm whether packets reach the destination at all. The commands in this guide cover those basics.

1. hostname

The hostname command shows the current system hostname. This is useful when you are logged into a server and want to confirm which machine you are on.

hostname

web01.example.net

See full host information with hostnamectl

hostnamectl

 Static hostname: web01.example.net
       Icon name: computer-vm
         Chassis: vm
      Machine ID: 0f6d8a3d9a0b4f1d9e0abc1234567890
         Boot ID: 6b0e1e9d9f4e4d42bdbd123456789abc
  Operating System: AlmaLinux 9.4
       CPE OS Name: cpe:/o:almalinux:almalinux:9::baseos
            Kernel: Linux 5.14.0-427.35.1.el9_4.x86_64
      Architecture: x86-64

2. ping

ping checks basic network reachability by sending ICMP echo requests. It is a fast way to see whether a host responds and how long the round trip takes.

ping -c 4 example.com

PING example.com (93.184.216.34) 56(84) bytes of data.
64 bytes from 93.184.216.34: icmp_seq=1 ttl=56 time=14.2 ms
64 bytes from 93.184.216.34: icmp_seq=2 ttl=56 time=13.8 ms
64 bytes from 93.184.216.34: icmp_seq=3 ttl=56 time=14.4 ms
64 bytes from 93.184.216.34: icmp_seq=4 ttl=56 time=14.1 ms

--- example.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 13.861/14.123/14.449/0.223 ms

If ping fails, it does not always mean the host is down. Some servers and firewalls block ICMP responses.

3. ip addr

ip addr show displays network interfaces and their IP addresses. On modern Linux systems, this is often the first command to use when checking interface details.

ip addr show

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    inet 127.0.0.1/8 scope host lo
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default
    inet 203.0.113.25/24 brd 203.0.113.255 scope global dynamic eth0
    inet6 2001:db8:10::25/64 scope global dynamic mngtmpaddr
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    inet 172.17.0.1/16 scope global docker0

This is especially useful when you need to confirm the server IP, identify private versus public addresses, or check whether an interface is actually up.

4. ifconfig

ifconfig is an older tool, but plenty of people still use it and many online examples still reference it. If the net-tools package is installed, you can run:

ifconfig

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 203.0.113.25  netmask 255.255.255.0  broadcast 203.0.113.255
        inet6 2001:db8:10::25  prefixlen 64  scopeid 0x0<global>
        ether 52:54:00:12:34:56  txqueuelen 1000  (Ethernet)
        RX packets 128547  bytes 98654122 (94.1 MiB)
        TX packets 102873  bytes 18345678 (17.4 MiB)

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0

If you see command not found, that usually means the system uses ip instead.

5. ip route

ip route shows the routing table, including the default gateway.

ip route

default via 203.0.113.1 dev eth0 proto dhcp src 203.0.113.25 metric 100
203.0.113.0/24 dev eth0 proto kernel scope link src 203.0.113.25
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1

If a server can talk to its own network but cannot reach the wider internet, the default route is one of the first things to check.

6. ss

ss helps you see open ports and listening services. It is a modern replacement for many common netstat checks.

ss -tulpn

Netid State  Recv-Q Send-Q Local Address:Port  Peer Address:Port Process
tcp   LISTEN 0      128    0.0.0.0:22        0.0.0.0:*       users:(("sshd",pid=813,fd=3))
tcp   LISTEN 0      511    0.0.0.0:80        0.0.0.0:*       users:(("nginx",pid=1256,fd=6))
tcp   LISTEN 0      511    0.0.0.0:443       0.0.0.0:*       users:(("nginx",pid=1256,fd=7))
udp   UNCONN 0      0      127.0.0.53:53     0.0.0.0:*       users:(("systemd-resolved",pid=590,fd=13))

If you expect a service to be reachable but nothing is listening on the expected port, the issue may be the service itself rather than the network.

7. traceroute or tracepath

These commands show how traffic travels to a destination. They are useful when packets appear to get lost or delayed between networks.

traceroute example.com

traceroute to example.com (93.184.216.34), 30 hops max, 60 byte packets
 1  203.0.113.1 (203.0.113.1)  0.601 ms  0.544 ms  0.510 ms
 2  198.51.100.14 (198.51.100.14)  2.113 ms  2.049 ms  1.994 ms
 3  198.51.100.58 (198.51.100.58)  5.982 ms  6.210 ms  6.143 ms
 4  93.184.216.34 (93.184.216.34)  14.233 ms  14.111 ms  14.047 ms

If traceroute is not installed, tracepath example.com is often available and easier to use.

8. dig and nslookup

DNS problems are extremely common, so it is worth learning one DNS lookup tool properly. We have a full Dig Command Guide, but here is the short version:

dig +short example.com

93.184.216.34

nslookup example.com

Server:         127.0.0.53
Address:        127.0.0.53#53

Non-authoritative answer:
Name:   example.com
Address: 93.184.216.34

Use these commands when you need to confirm whether a hostname resolves to the IP you expect.

9. curl

curl is not a low-level network command, but it is one of the best ways to test whether a web service responds.

curl -I https://example.com

HTTP/2 200
content-type: text/html; charset=UTF-8
cache-control: max-age=604800
date: Sun, 03 May 2026 14:10:18 GMT
server: nginx

This tells you more than ping does. A host may respond to the network, but your website or API may still be returning an error. curl helps bridge that gap.

Firewall checks with firewalld

If a service is listening locally but still cannot be reached, check whether the firewall allows the service or port.

firewall-cmd --state
firewall-cmd --get-active-zones
firewall-cmd --list-all

public (active)
  interfaces: eth0
  services: cockpit dhcpv6-client ssh http https
  ports: 8080/tcp

For full examples, see the firewalld Guide and firewalld Cheat Sheet.

Basic networking commands quick reference