How to Check Internet Connection in Linux Command Line and Shell Script

A Linux server can fail internet access at different layers. The default route may be missing, DNS may be broken, ICMP may be blocked, TCP ports may be filtered, or HTTP access may require a proxy. Because of this, one command is not always enough to prove that the server is fully connected to the internet.

This guide shows tested commands to check internet connectivity from the Linux command line. Use the command that matches what you want to prove:

• Use ip route get to confirm the system has a route toward an external IP address.
• Use getent, dig, nslookup, or host to test DNS name resolution.
• Use ping to test ICMP reachability.
• Use curl or wget to test real HTTP or HTTPS internet access.
• Use nc, Bash /dev/tcp, or telnet to test whether a remote TCP port is reachable.

The examples below were tested on a Linux host with ping from iputils 20240905, curl 8.12.1, GNU Wget 1.24.5, OpenBSD netcat 1.228, BIND DNS tools 9.20.11, and iproute2 6.14.0. Your IP addresses, latency, DNS resolver, and route output can be different.

1. Check whether Linux has a route to the internet

Start with the route table when the server looks completely offline. This does not contact 1.1.1.1; it asks the kernel which interface, gateway, and source IP it would use for that destination.

ip route get 1.1.1.1

Tested output:

1.1.1.1 via 10.0.2.2 dev enp0s3 src 10.0.2.15 uid 0
    cache

This output means the host has a route to 1.1.1.1 through gateway 10.0.2.2 using interface enp0s3. It does not prove that DNS, firewall rules, or web access is working.

If this command says the network is unreachable, first check the IP address, gateway, and interface state. The nmcli command examples article is useful when you need to inspect or configure NetworkManager connections.

2. Check DNS resolution from the command line

DNS checks answer a different question: can the Linux host convert a domain name into an IP address? DNS may work even when web access is blocked, so treat this as a DNS test, not a complete internet test.

Use getent first if you want to test name resolution through the normal system resolver path configured in /etc/nsswitch.conf:

getent hosts example.com

Tested output:

2606:4700:10::ac42:93f3 example.com
2606:4700:10::6814:179a example.com

Use dig when you want DNS-focused output:

dig +short example.com

Tested output:

104.20.23.154
172.66.147.243

You can also use nslookup:

nslookup example.com

Tested output:

Server:         127.0.0.53
Address:        127.0.0.53#53

Non-authoritative answer:
Name:   example.com
Address: 172.66.147.243
Name:   example.com
Address: 104.20.23.154

Or host:

host example.com

Tested output:

example.com has address 104.20.23.154
example.com has address 172.66.147.243
example.com has IPv6 address 2606:4700:10::ac42:93f3
example.com has IPv6 address 2606:4700:10::6814:179a
example.com mail is handled by 0 .
example.com has HTTP service bindings 1 . alpn="h2" ipv4hint=104.20.23.154,172.66.147.243 ipv6hint=2606:4700:10::6814:179a,2606:4700:10::ac42:93f3

If DNS fails but IP-based tests work, troubleshoot resolver configuration, /etc/resolv.conf, NetworkManager DNS settings, or your local DNS server. If you run your own DNS service, see the guide to configure a BIND DNS server.

3. Check internet reachability with ping

ping sends ICMP echo requests. It is quick and useful, but many networks block ICMP, so a failed ping does not always mean HTTPS or application traffic is down.

First ping a public IP address. This tests routing plus ICMP without depending on DNS:

ping -c 1 -W 2 1.1.1.1

Tested output:

PING 1.1.1.1 (1.1.1.1) 56(84) bytes of data.
64 bytes from 1.1.1.1: icmp_seq=1 ttl=255 time=8.89 ms

--- 1.1.1.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 8.888/8.888/8.888/0.000 ms

Then ping a domain name. This tests DNS resolution plus ICMP reachability:

ping -c 1 -W 2 example.com

Tested output:

PING example.com (172.66.147.243) 56(84) bytes of data.
64 bytes from 172.66.147.243: icmp_seq=1 ttl=255 time=8.64 ms

--- example.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 8.644/8.644/8.644/0.000 ms

In the statistics section, 1 received and 0% packet loss show that the ping succeeded. For more ping options, see the Linux ping command examples.

4. Check real HTTPS access with curl

For most servers, curl is the most practical internet check because applications usually need HTTP or HTTPS access, not only ICMP. The command below requests https://example.com, discards the body, prints the HTTP status code, and stops after 5 seconds.

curl -fsS --max-time 5 -o /dev/null -w 'http_code=%{http_code} remote_ip=%{remote_ip}\n' https://example.com

Tested output:

http_code=200 remote_ip=2606:4700:10::6814:179a

The important result is http_code=200, which means the HTTPS request succeeded. The remote_ip value may be IPv4 or IPv6 depending on your resolver and network.

Useful options in this command:

• -f makes curl fail on HTTP error responses such as 404 or 500.
• -sS keeps normal output quiet but still shows errors.
• --max-time 5 prevents a script from hanging too long.
• -o /dev/null discards the page body.
• -w prints only the fields you want in the output.

See the curl command examples article for more options. If the command is missing on Ubuntu, use install cURL on Ubuntu; on other distributions see the curl command not found guide.

5. Check internet access with wget

wget --spider checks whether a URL is reachable without downloading the page content. This is useful on systems where wget is already installed.

wget -q --spider --timeout=5 https://example.com
echo $?

Tested output:

0

Exit status 0 means the URL check succeeded. A non-zero exit status means the check failed, but you still need to inspect the error to know whether it was DNS, TCP, TLS, HTTP, or proxy related.

For more wget examples, see the wget command in Linux article. If the command is missing, see wget command not found.

6. Check a remote TCP port with nc, Bash dev tcp, or telnet

A TCP port check is useful when ping is blocked or when you only need to know whether an outbound connection to a specific IP and port works. For HTTPS connectivity, test port 443.

Use nc when available:

nc -vz -w 3 1.1.1.1 443
echo $?

Tested output:

Connection to 1.1.1.1 443 port [tcp/https] succeeded!
0

Use Bash /dev/tcp when you want a simple check without netcat. This is a Bash feature, not a POSIX shell feature:

timeout 5 bash -c 'cat < /dev/null > /dev/tcp/1.1.1.1/443'
echo $?

Tested output:

0

Use telnet only when it is already installed or when you are working on an older system:

timeout 5 bash -c 'printf "quit\n" | telnet 1.1.1.1 443'
echo $?

Tested output:

Trying 1.1.1.1...
Connected to 1.1.1.1.
Escape character is '^]'.
Connection closed by foreign host.
0

A successful TCP connection proves that the remote IP and port are reachable. It does not prove that the HTTPS certificate, HTTP response, proxy settings, or application login works. For more port troubleshooting, see how to check whether a port is open in Linux.

7. Use a shell script to check internet connection

For scripts, keep the check short, deterministic, and easy to interpret. The following script uses curl because it validates HTTPS access and returns a reliable exit code.

#!/usr/bin/env bash

if curl -fsS --max-time 5 -o /dev/null https://example.com; then
    echo "online: https check succeeded"
else
    echo "offline: https check failed"
fi

Tested output:

online: https check succeeded

You can place this logic inside a Bash function if you need to reuse it in a larger script:

check_internet_access() {
    curl -fsS --max-time 5 -o /dev/null https://example.com
}

if check_internet_access; then
    echo "online: https check succeeded"
else
    echo "offline: https check failed"
fi

For script control flow basics, see Bash if else examples and Bash function examples.

8. Which command should you use?

Use this quick mapping when choosing a command:

nmap and traceroute can also help with network diagnosis, but they are not required for a basic internet connectivity check. They were not installed on the test host used for this article, so they are not used as primary tested examples here. If you need deeper packet or path troubleshooting, tools such as tcpdump can help; see the tcpdump command examples.

Summary

To check internet connection in Linux, do not rely on a single command for every situation. Start with ip route get when routing is in doubt, use DNS tools when names do not resolve, use ping for quick ICMP checks, use nc or Bash /dev/tcp for TCP port checks, and use curl or wget when you need to prove real HTTP or HTTPS access.

For automation, curl -fsS --max-time 5 -o /dev/null https://example.com is usually the clearest shell-script check because it tests the same web connectivity most Linux servers and applications actually need.