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Introduction
Along with windows, iOS and macOS, Linux is also an operating system. An operating system manages the communication between the hardware and software. Linux is open-source, free of cost and highly secure.
A network is a spider web-like structure that connects digital devices to each other. Linux provides a list of commands that can be used to configure, troubleshoot and manage these networks.
In this article, we will discuss the commonly used Linux networking commands.
ip command
This command is used to manipulate and configure network interfaces.
➡️ Usage
Use it to view all the active network interfaces. Use it to assign and unassign a network’s IP address. You can also start and stop the network using this command.
➡️ Syntax
ip a <option>
Or
ip addr <option>
Function
Description
Command
Listing the IP addresses
You can use address show or addr show or addr or a as command line option along with the ip command to display the list of all the active IP addresses in the network.
To display the ipv4 and ipv6 addresses add -4 and -6 to the command respectively.
ip address show
ip addr show
ip addr
ip a
For ipv4
ip -4 addr
For ipv6
ip -6 addr
Adding an IP address
Use the ip addr add command along with the <ip address> and the name of the <interface>.
ip addr add <ip number> dev <interface name>
Deleting an IP address
Use the del option along with the ip command to delete the IP address. Mention the ip address and the interface to which it belongs.
ip addr del <ip number> dev <interface name>
Start and stop an interface
Use the up argument to start the network interface and down argument to stop the network interface.
Start
ip link set wlp6s0 up
Stop
ip link set wlp6s0 down
ifconfig Command
It is used to initialize and configure network interfaces. This command was later replaced by the ip command.
➡️ Usage
Start and stop the network interfaces.
Use it to add an IP address.
Use it to delete an IP address.
➡️ Syntax
ifconfig [...OPTIONS] [INTERFACE]
Functionality
Description
Command
List all active networks
All the network routes that are active will be listed.
ifconfig
List all networks
All the networks whether active or inactive are listed.
ifconfig -a
Assign an IP address
Mention an IP address that should be given to the network interface.
ifconfig eth0 <ip address> netmask <mask>
To start a network
Use it to activate the network.
ifconfig up eth0
To stop a network
Use it to deactivate the network.
ifconfig down eth0
Note: It is an obsolete command. It has been replaced by the ip command.
Traceroute Command
This command can be used to display how the packets are transferred from the local host to another network. It shows the hops and the path taken by the packets to reach from the local host to another network system.
It is a troubleshooting command.
➡️ Usage
This command will display the path taken by the packets to travel from the local host to another network server.
➡️ Syntax
traceroute<server name or server ip address>
➡️ Install traceroute
In order to use this functionality you will need to install it manually.
Run the following command to install the traceroute functionality:
On Ubuntu & Debian Systems:
sudo apt-get install traceroute
Or on CentOS:
yum install traceroute -y
Functionality
Description
Command syntax
Trace
Use this command to display the hops and the path taken by the packets.
traceroute <server name> or <server IP address>
Trace using Ipv6
Use Ipv6 protocol to trace the path of the packet.
traceroute -6 <server name> or <server IP address>
Trace using Ipv4
Use Ipv4 protocol to trace the path of the packet.
traceroute -4 <server name> or <server IP address>
Set number of queries per hop
Mention the number of hops a packet should make per query.
traceroute -q <number of hops to make> <server name or IP address>
Interface to use
Use the ‘i’ option to specify the interface to be used. If it is not set, it will use the interface according to the route table.
traceroute -i wlp3s0b1<server name or IP address>
Maximum hops
Use -m option to set the maximum number of hops. By default this value is set to 30.
traceroute -m <integer value indicating max number of hops> <server name or IP address>
Getting help
A list of all the list options and their usage will appear.
Press ‘q’ to quit.
traceroute --help
nslookup Command
This command is used to obtain DNS related queries.
➡️ Usage
It can be used to obtain the domain name and the Ip address, along with some other information related to the DNS records.
➡️ Syntax
nslookup <domainName>
Information Type
Description
Command syntax
Domain information
Use the nslookup command to obtain the information of the domain.
nslookup <domainName>
Ns records
Use type=ns to display the NS records of the domain.
nslookup -type=ns <domainName>
MX records
Use the query=mx to find the MX records responsible for email exchanges.
nslookup -query=mx <domainName>
All records
Use type=any to view all the DNS records
nslookup -type=any <domainName>
ping command
The receipt of corresponding Echo Reply messages is displayed, along with round-trip times. Ping is the primary TCP/IP command used to troubleshoot connectivity, reachability, and name resolution.
Stop ping by pressing CTRL+C. After every ping command, a summary report is displayed. It contains the following information :
Min - Minimum time that it takes to get a response from the host that has been pinged from your end.
Avg - Average time that it takes to get a response from the host that has been pinged from your end.
Max - Maximum time that it takes to get a response from the host that has been pinged from your end.
Frequently Asked Questions
What is the advantage of using commands?
Commands make use of Linux fast. Many operations not available in GUI versions can be performed using commands only. Commands give a powerful way to handle Linux systems.
What is the sudo command?
It is one of the essential commands. It gives the user superuser/root privileges. Be careful while using this command, as you can access critical sections of the server using this command.
How to use the Traceroute command in Linux?
You can install the Traceroute by running this command - sudo apt-get install traceroute. You can use this command after the installation is over.
Conclusion
Congratulations on finishing this article. In this article, we discussed some commonly used networking commands in linux. We discussed their usage, syntax and common examples.
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