How to know hostname linux

Linux Find Out My Machine Name/Hostname

The procedure to find the computer name on Linux:

1. Open a command-line terminal app (select Applications > Accessories > Terminal), and then type:
2. hostname
   OR
   hostnamectl
   OR
   cat /proc/sys/kernel/hostname
3. Press [Enter] key

Linux find hostname using hostnamectl

Type the following command if you are using systemd based Linux distro:
$ hostnamectl

It is possible to filter output using the grep command:
$ hostnamectl | grep ‘hostname’
OR simply use the cat command as follows too:
$ cat /proc/sys/kernel/hostname

Linux find computer name using hostname command

At the terminal type hostname command:
$ hostname
Sample outputs
vivek-laptop.nixcraft.in
Where,

• vivek-laptop : You computer name.
• nixcraft.in : Your dNS domain name.
• vivek-laptop.nixcraft.in : Your computer name with Fully Qualified Domain Name (FQDN).

To see the domain part of the FQDN (Fully Qualified Domain Name), enter:
$ dnsdomainname
Sample outputs:

• No ads and tracking
• In-depth guides for developers and sysadmins at Opensourceflare✨
• Join my Patreon to support independent content creators and start reading latest guides:
  • How to set up Redis sentinel cluster on Ubuntu or Debian Linux
  • How To Set Up SSH Keys With YubiKey as two-factor authentication (U2F/FIDO2)
  • How to set up Mariadb Galera cluster on Ubuntu or Debian Linux
  • A podman tutorial for beginners – part I (run Linux containers without Docker and in daemonless mode)
  • How to protect Linux against rogue USB devices using USBGuard

Join Patreon ➔

How Do I Change My Hostname?

The hostname commands set the host name using the following syntax. Please note that only the super-user / root can change the names. To switch to the root user by typing su – and entering the root password, when prompted.
# hostname newhostname.nixcraft.in
# hostname laptop.nixcraft.net.in
# hostnamectl set-hostname laptop.nixcraft.in
You need to edit /etc/hostname or /etc/sysconfig/network file to set hostname permanently. See our previous FAQ about changing hostname using configuration files.

Conclusion

The hostnamectl command may be used to query and change the system hostname and related settings on modern Linux distros such as Debian, Ubuntu, CentOS/RHEL, Fedora, Arch Linux and more.

Getting help

I strongly suggest that your read the man pages by typing the man command:
$ man hostname
$ man hostnamectl
$ hostnamectl —help

Источник

How To Find Hostname In Linux

A Hostname is an unique alphanumeric label assigned to a Linux system in order to identify it on the network. It can also contain a few special characters such as hyphen (-), period (.), and underscore (_). A typical hostname consists of up to 253 characters. Generally, the hostname is stored in /etc/hostname file in most Linux distributions. In this brief guide, we will learn about various commands to find hostname in Linux operating systems.

1. Find Hostname in Linux with hostname command

The hostname command is used to display a Linux system’s DNS name and Hostname. It also allows the users to change or set the Hostname.

To find Hostname in Linux, run hostname command without any options:

Find Hostname in Linux with hostname command

As you see in the output, my Linux system’s hostanme is ostechnix.

If you want to show the FQDN (Fully Qualified Domain Name), run:

2. Display Hostname with hostnamectl command in Linux

The hostnamectl command is used to get and set the system hostname and related settings in Linux.

To display the hostname of your Linux machine, run hostnamectl command without any options:

Sample output:

Display Hostname with hostnamectl command in Linux

Unlike the hostname command, hostnamectl displays a few more details of your system such as type of the system (laptop or desktop), Boot & machine ID, Operating system and Kernel version, Architecture etc.

To display only the Hostname, use —static flag:

3. Check Linux Hostname with nmcli command

The nmcli is a command line tool to control NetworkManager and report the network status. With nmcli, we can create, display, edit, delete, activate, and deactivate network connections, as well as control and display network device status.

To check the hostame of a Linux system with nmcli tool, run this command:

4. View Hostname using uname command

The uname is a command line tool to print all system information such as hostname, Kernel release, Kernel version, operating system, and processor architecture etc.

To view hostname with uname command, run it with -n option:

5. Get Hostname by reading /etc/hostname file

As stated already, the hostname is stored in /etc/hostname file in most Linux distributions. To get the hostname of a Linux system, simply display the contents of /etc/hostname file:

These are the most commonly used commands to find hostname in Linux. There are also a two uncommon ways to check Linux hostname. They have been given below for your reference.

6. Print Hostname in Linux with sysctl command

The sysctl command is used to list and modify kernel parameters at runtime.

We can print a Linux system’s hostname using sysctl command line below:

7. Determine Hostname in Linux with ProcFS

Proc file system (or shortly procfs) is a virtual file system maintained by the Linux kernel. It is also sometimes referred to as a process information pseudo-file system. It doesn’t contain ‘real’ files but runtime system information such as system memory, devices mounted, hardware configuration etc. All these information are available under a special directory named /proc in Linux.

To determine the hostname of Linux with prcfs, run:

You know now different methods to view a Linux system’s hostname. How will you change it? The following guide explains how to set a new hostname or change the existing hostname, either from command line or from Settings section in graphical mode.

Источник

All you need to know about hostname in Linux

Published: May 31, 2017 | Modified: June 24, 2020

Learn what is hostname, how to set hostname and how to change hostname in Debian and RedHat based Linux systems.

The hostname is a prime identity of Linux servers in the human world! Obviously, the IP address is the main component to identify the system in the environment. In this article, we are going to see anything and everything about the hostname. We will walk through what is the hostname, how to set hostname, how to change hostname etc. Let’s start with the basics of the hostname.

What is hostname

The hostname is the humanly readable identity of the server. Any server is identified by IP address in the network but to identify easily hostname is also given. Normally FQDN (Fully Qualified Domain Name) is expected for the system but even Domain name (the name before the dot) is also fine for systems under private networks. The hostname can be alpha-numeric

Generally hostname standards to the maximum of 255 bytes long. But normally people prefer to keep it 10-12 characters long so that it’s easy to remember. Kernel variables _POSIX_HOST_NAME_MAX or HOST_NAME_MAX defines your current max limit of hostname. You can get their values using getconf a command like below :

How to set hostname in Linux

A quick command in all-new Linux distros is hostnamectl . Use set-hostname switch and your new hostname as an argument.

For more details read on …

Hostname is defined in files

• /etc/hosts for networking
• /etc/hostname : This will be read by boot scripts on boot time and set its value.
• /proc/sys/kernel/hostname : Current hostname.
• /etc/sysconfig/network : Networking (HOSTNAME=”server1″ parameter)

In above files, you can only view current hostname (being used by the live kernel) under proc file only. Rest all files are used to lookup or set hostname at boot time. So if you change hostname using hostname command then it won’t reflect in rest files. It will only reflect in the proc file.

You can set the hostname of your choice in /etc/hostname or /etc/sysconfig/network and restart network service to notify kernel about it.

How to change hostname in Linux

The current hostname can be checked by typing hostname command without any argument. The hostname can be changed by simply using hostname command followed by the name of your choice.

Cautions : Do not change hostname on live production systems!

Please make a note that change is dynamic and not permanent. After the system reboot, the hostname will be returned to what it was earlier.

Change hostname permanently in Linux

On RedHat systems : You can edit file /etc/sysconfig/network (define in HOSTNAME=”xyz”) & reboot system

On Debian systems : You can edit file /etc/hostname & call /etc/init.d/hostname.sh script ( /etc/init.d/hostname.sh start )

You can even change the hostname using the system control command. Use parameter kernel.hostname and define its value like below :

On Suse systems : Edit file /etc/HOSTNAME and add hostname in it. There will be no parameter and value format. Only you have to enter hostname like below :

Change hostname permanently in clone, template VM & cloud clones

If you have a system which is prepared using clone, template from VMware or cloud clone deploy then you should do the following :

Edit file /etc/cloud/cloud.cfg and change parameter ‘preserve_hostname’ to true. You can do it using one-line sed script as below :

Also, change DHCP related parameter DHCLIENT_SET_HOSTNAME in file /etc/sysconfig/network/dhcp to no. So that hostname wont be changed by DHCP in the next reboot. Again, you can use one line sed to do that as below :

That’s it. These are two extra steps you need to take on cloud or VM servers.

How to configure FQDN in Linux

Another thing around the hostname is to set FQDN for Linux server i.e. Fully Qualified Domain Name. Generally you should be doing in via DNS in your environment but /etc/hosts always get checked first. So its good practise to define FQDN at /etc/hosts file

Use format to add/edit entry in /etc/hosts and you are good to go. Sample entry below –

You can verify Linux server’s FQDN by using command hostname -f

Источник

How to Use the hostname Command in Linux

Home » SysAdmin » How to Use the hostname Command in Linux

The Linux hostname command is used to view or change a system’s domain and hostname. It can also check a computer’s IP address.

In this tutorial, we will cover all the ways you can use the hostname command on Linux and how to change your computer’s hostname on a Linux system.

• A system running Linux
• Access to the command line / terminal window

hostname Command Syntax

The hostname command uses the following format:

Use the [options] parameter to add more specific instructions to the hostname command. Without it, the default output shows your computer’s hostname:

Use the [new_hostname] parameter when you want to change your computer’s hostname.

hostname Command Examples

The hostname command has a number of options you can use for more specific outputs:

• -a , —alias : Displays the alias name of the host.
• -A , —all-fqdns : Displays every FQDN (Fully Qualified Domain Name) of the computer.
• -b , —boot : Always set a hostname.
• -d , —domain : Display DNS domain name.
• -f , —fqdn , —long : Display the FQDN.
• -F , —file : Check a file to recover and display the hostname.
• -h , —help : Print the help message as the output.
• -i , —ip-address : Display the computer’s IP address.
• -I , —all-ip-addresses : Display all of the computer’s network addresses.
• -s , —short : Display the short version of the hostname.
• -v , —verbose : Expand all output to verbose.
• -y , —yp , —nis : Display the NIS domain name.

Display Hostname

Using the hostname command without any additional options displays the computer’s hostname:

Display Short Hostname

Use the -s or —short option to display the short version of the hostname, which is cut off at the first dot:

Display Alias

Use the -a or —alias option to display the alias (substitute hostname) of the host if one is set. There are very few cases where this option is useful, and its use is no longer recommended.

Search for Hostnames

Use the -F or —file option to search a specific file (such as hostname or hosts) and change your computer’s hostname to match the content of the file:

Note: When using the -F or —file options, also specify the path to the file you want to check.

Force Default Hostname

If you don’t want to have a specific file containing the hostname, or want to leave that file empty, use the -b or —boot option. This makes your computer use the default hostname (localhost) until you set a different one:

Display Domain Name

Use the -d or —domain option to display the name of your DNS domain:

Display FQDN

If you want to display a system’s FQDN, use the -f , —fqdn , or —long option:

A FQDN contains the short hostname and the DNS domain name.

Display All FQDNs

To display each FQDN of your machine, use the -A or —all-fqdns option:

This option lists out all of your network addresses and their DNS domain names. It skips any addresses that it can’t translate.

Note: Different network addresses may translate to same DNS domain names. This can result in duplicate output entries when using -A or —all-fqdns options.

Display NIS Domain

If you’re using NIS (Network Information Service), you can check your NIS domain name with the -y , —yp , or —nis option:

Change NIS Domain Name

Use this command with the following format to change your NIS domain name:

Display Related Network Addresses

The hostname command also lets your display network addresses tied to a hostname. To do this, use the -i or —ip-address option:

This command only works if the hostname can be resolved.

Display All Network Addresses

Use the -I or —all-ip-addresses option to display all of the host’s network addresses. Unlike -i , this option doesn’t depend on hostname resolution:

Change Hostname Until Reboot

You can change your computer’s hostname with the hostname command. To do this, use the following format:

Any changes to the hostname you make using this command will only last until the next reboot.

Change Hostname Permanently

To change the hostname permanently, use a text editor like Nano to make changes to the hostname and hosts files:

You can also use the hostnamectl command to permanently change the hostname:

Additional hostname Options

Use the -V or —version option to print out the version of the hostname software package on your Linux system:

If you need help with any of the commands, use the -h or —help option to print out a help message:

After following this guide, you now know how to use the hostname command in Linux and all the options that can extend its use.

For more Linux commands, check out our Linux Commands Cheat Sheet.

Источник