Ten Useful Linux Networking Commands

One of the key features of Linux is its robust networking capabilities, which allow users to easily connect to and manage networks. There are a wide variety of Linux commands that can be used to perform various networking tasks, such as configuring network interfaces, troubleshooting network issues, and monitoring network activity.

Here are some common Linux networking commands that you might find useful:

1. ifconfig: This command is used to configure network interfaces. It can be used to view the current configuration of network interfaces, as well as to set specific parameters such as the IP address and netmask.
2. ip: This command is similar to ifconfig, but it is more powerful and flexible. It can be used to perform a variety of tasks, including configuring network interfaces, routing, and policy routing.
3. ping: This command is used to test the connectivity between two devices on a network. It works by sending a small packet of data to the target device and measuring the time it takes for a response to be received.
4. traceroute: This command is used to trace the route that a packet of data takes from one device to another. It can be used to troubleshoot network issues by identifying the specific points where packets are being lost or delayed.
5. netstat: This command is used to view network statistics and information about active connections. It can be used to monitor network activity and identify potential issues.
6. ss: This command is similar to netstat, but it is more efficient and provides more detailed information about network connections.
7. tcpdump: This command is used to capture and analyze network traffic. It can be used to troubleshoot network issues by analyzing packets and identifying problems such as misconfigured protocols or security issues.
8. nmap: This command is used to scan networks and perform network mapping. It can be used to identify active devices on a network, as well as to perform security assessments and identify vulnerabilities.
9. telnet: This command is used to establish a connection to a remote host using the Telnet protocol. It can be used to access servers, routers, and other network devices remotely.
10. ssh: This command is used to establish a secure shell connection to a remote host. It is commonly used to remotely access servers and other network devices, and it is more secure than telnet.

ifconfig command examples

Here are some examples of how the ifconfig command can be used. View the current configuration of all network interfaces:

ifconfig

This will display the current configuration of all network interfaces on the system, including their name, IP address, netmask, and other information. View the current configuration of a specific network interface:

ifconfig eth0

This will display the current configuration of the network interface named eth0, including its name, IP address, netmask, and other information. Set the IP address and netmask of a network interface:

ifconfig eth0 192.168.1.100 netmask 255.255.255.0

This will set the IP address of the eth0 interface to 192.168.1.100 and the netmask to 255.255.255.0. Enable or disable a network interface:

ifconfig eth0 up
ifconfig eth0 down

The up command will enable the eth0 interface, while the down command will disable it. These are just a few examples of how the ifconfig command can be used. It has many other options and arguments that can be used to configure network interfaces in various ways. For more information, you can consult the ifconfig man page or online resources.

ip command examples

Here are some examples of how the ip command can be used. To view the current configuration of all network interfaces:

ip addr

This will display the current configuration of all network interfaces on the system, including their name, IP address, and other information. View the current configuration of a specific network interface:

ip addr show eth0

This will display the current configuration of the network interface named eth0, including its name, IP address, and other information. Set the IP address and netmask of a network interface:

ip addr add 192.168.1.100/24 dev eth0

This will set the IP address of the eth0 interface to 192.168.1.100 and the netmask to 255.255.255.0. Enable or disable a network interface:

ip link set eth0 up
ip link set eth0 down

The up command will enable the eth0 interface, while the down command will disable it. The ip command has many other options and arguments that can be used to configure network interfaces and routes in various ways. For more information, you can consult the ip man page.

ping command examples

Here are some examples of how the ping command can be used. To test connectivity to a specific IP address:

ping 192.168.1.1

his will send a series of ping packets to the specified IP address and display the results, including the round-trip time for each packet and the percentage of packets that were lost. Test connectivity to a domain name:

ping www.example.com

This will resolve the domain name to an IP address and then send a series of ping packets to that address, displaying the results as in the previous example. Limit the number of ping packets:

ping -c 5 192.168.1.1

To ping a host and display detailed output:

ping -v google.com

To ping a host and suppress all output except for summary statistics:

ping -q -c 5 google.com

To ping a host and record the time of each request and response in a file:

ping -D google.com > ping.log

These are just a few more examples of how you can use the ping command in Linux. You can use the man command to view the full documentation for the ping command and learn about all of the available options.

traceroute command examples

The traceroute command is used to trace the route that packets take from the host where the command is run to a specified destination host. It can be useful for troubleshooting network connectivity issues and for understanding how traffic is routed over the Internet. Here are a few examples of how you can use the traceroute command in Linux. To trace the route to a specific host by its IP address:

traceroute 192.168.1.1

To trace the route to a host by its domain name:

traceroute google.com

To specify the maximum number of hops to search for a route:

traceroute -m 20 google.com

To trace the route to a host using UDP packets:

traceroute -u google.com

To trace the route to a host using TCP SYN packets:

traceroute -T google.com

There are many other options and flags available for the traceroute command. You can use the man command to view the full documentation for the traceroute command and learn about all of the available options.

netstat command examples

The netstat command is used to display various network-related statistics and information. Here are a few examples of how you can use the netstat command in Linux. To display a list of all active network connections:

netstat

To display a list of all listening network connections:

netstat -l

To display a list of all active network connections and the process IDs of the programs that own them:

netstat -p

To display detailed information about all active network connections:

netstat -a

To display a summary of network traffic statistics:

netstat -s

To display a list of all active network connections, including the name of the associated program:

netstat -p --program

There are many other options and flags available for the netstat command. Use the man command to view the full documentation for the netstat command and learn about all of the available options.

linux ss command examples

The ss command is a utility for displaying socket statistics in Linux. It can be used to display information about network connections, routing tables, and a variety of other network-related information. Here are a few examples of how you can use the ss command in Linux. To display a list of all active network connections:

ss

To display a list of all listening network connections:

ss -l

To display a list of all active network connections and the process IDs of the programs that own them:

ss -p

To display detailed information about all active network connections:

ss -a

To display a summary of network traffic statistics:

ss -s

To display a list of all active TCP connections:

ss -t

There are many other options and flags available for the ss command. You can use the man command to view the full documentation for the ss command

tcpdump command examples

The tcpdump command is a powerful tool for capturing and analyzing network traffic in Linux. Here are a few examples of how you can use the tcpdump command. To capture traffic on all interfaces and save the output to a file:

tcpdump -w capture.pcap

To capture traffic on a specific interface and display the output in real-time:

tcpdump -i eth0

To capture traffic for a specific host:

tcpdump host 192.168.1.1

To capture traffic for a specific port:

tcpdump port 80

To capture traffic for a specific protocol, in this case icmp:

tcpdump icmp

To display detailed information about each packet captured:

tcpdump -vv

As always, there are many more tcpdump commands to learn! Check out the man page for more information.

nmap command examples

The nmap command is a utility for network exploration and security auditing in Linux. It can be used to scan networks and hosts to identify open ports, services, and operating systems. Here are a few examples of how you can use the nmap command in Linux. To scan a range of IP addresses with nmap:

nmap 192.168.1.1-100

To scan a list of hosts specified in a text file:

nmap -iL hosts.txt

To scan all hosts on a specific network:

nmap 192.168.1.0/24

To scan a host using a specific port range:

nmap -p 1-1000 192.168.0.1

To scan a host and perform a more thorough and intense scan:

nmap -T4 -A 192.168.0.1

linux telnet command examples

The telnet command is a utility for establishing a connection to a remote host using the Telnet protocol. It can be used to remotely access servers, network devices, and other types of systems over a network. Here are a few examples of how you can use the telnet command in Linux. To connect to a remote host by its IP address:

telnet 192.168.1.1

To specify the port to connect to on the remote host:

telnet 192.168.0.1 80

To specify the local port to use when connecting to the remote host:

telnet -l 8000 192.168.0.1

To specify the Telnet terminal type to use when connecting to the remote host:

telnet -t vt100 192.168.0.1

These are just a few examples of how you can use the telnet command in Linux. There are many other options and flags available for the telnet command. You can use the man command to view the full documentation for the telnet command and learn about all of the available options.

It’s important to note that the Telnet protocol is considered insecure and is not recommended for use in modern networks. It sends all data, including passwords, in plaintext and is vulnerable to man-in-the-middle attacks. There are more secure alternatives available for remotely accessing systems over a network, such as Secure Shell (SSH).

ssh command examples

The ssh command is a utility for securely connecting to a remote host using the Secure Shell (SSH) protocol. It can be used to remotely access servers, network devices, and other types of systems over a network. Here are some examples of how you can use the ssh command in Linux. To connect to a remote host by its IP address:

ssh 192.168.1.1

To specify the port to connect to on the remote host:

ssh -p 22 192.168.1.1

To specify the user to authenticate as on the remote host:

ssh user@192.168.1.1

To specify the identity file (private key) to use for authentication:

ssh -i ~/.ssh/id_rsa user@192.168.1.1

To specify the cipher to use for encrypting the connection:

ssh -c aes256-cbc user@192.168.1.1

To forward a local port to a port on the remote host:

ssh -L 8080:localhost:80 user@192.168.1.1

To forward a port on the remote host to a local port:

ssh -R 8080:localhost:80 user@192.168.1.1

To execute a command on the remote host and exit:

ssh user@192.168.1.1 'ls -l /home/user'

To start a secure copy (SCP) session with the remote host:

scp file.txt user@192.168.1.1:/home/user

These are just a few examples of how you can use the ssh command in Linux. There are many other options and flags available for the ssh command. You can use the man command to view the full documentation for the ssh command and learn about all of the available options.

It’s important to note that the SSH protocol is widely used and considered secure for remotely accessing systems over a network. It uses strong encryption to protect data transmitted over the connection and supports several authentication methods, including the use of public-private key pairs. It is a much more secure alternative to the Telnet protocol, which sends all data, including passwords, in plaintext and is vulnerable to man-in-the-middle attacks.

Final Thoughts

These are just a few examples of the many Linux networking commands that are available. There are many others that can be used for a wide range of tasks, from configuring network interfaces and routing to monitoring network activity and troubleshooting issues. Whether you are a network administrator or a casual user, learning these commands can be an invaluable tool for managing and optimizing your Linux-based network.