- How to correctly set hostname and domain name?
- 5 Answers 5
- How to Edit Hosts File on Linux Mint 21
- What Is the Purpose of Hosts File in Linux Mint 21
- How to Edit the Hosts File in Linux Mint 21
- How to Block a Website through Hosts File
- Conclusion
- About the author
- Aaliyan Javaid
- How To Get Host Name and Domain Name Of Linux?
- Get Host name By Echoing Host name File
- Get Host name With hostname Command
- Get Fully Qualified Host name
- Hostname File
- Change Host name
- Get Domain Name
- How To Get Host Name and Domain Name Of Linux? Infografic
How to correctly set hostname and domain name?
I am also renting a domain name, let’s name it domain.org . What I would like to do would be to rename my server as server1.domain.org .
This means configuring my hostname as server1 and my domain name as domain.org .
How can I do it correctly?
Indeed, the manpage for hostname is not clear. To me at least:
- When called with one argument or with the —file option, the commands set the host name or the NIS/YP domain name. hostname uses the sethostname(2) function, while all of the three domainname, ypdomainname and nisdomainname use setdomainname(2). Note, that this is effective only until the next reboot. Edit /etc/hostname for permanent change.
- You cannot change the FQDN with hostname or dnsdomainname.
So it seems that editing /etc/hostname is not enough? Because if it really changed the hostname, it would have changed the FQDN. There’s also a trick I read to change the hostname with the command sysctl kernel.hostname=server1 , but nothing says whether this is the correct way or an ugly trick.
- What is the correct way to set the hostname?
- What is the correct way to set the domain name?
5 Answers 5
- You’ll want to edit /etc/hostname with your new hostname.
- Then, run sudo hostname $(cat /etc/hostname) .
Setting your domain, assuming you have a resolvconf binary:
- In /etc/resolvconf/resolv.conf.d/head , you’ll add then line domain your.domain.name (not your FQDN, just the domain name).
- Then, run sudo resolvconf -u to update your /etc/resolv.conf (alternatively, just reproduce the previous change into your /etc/resolv.conf ).
If you do not have resolvconf , just edit /etc/resolv.conf , adding the domain your.domain.name line.
Finally, update your /etc/hosts file. There should be at least one line starting with one of your IP (loopback or not), your FQDN and your hostname. grepping out ipv6 addresses, your hosts file could look like this:
127.0.0.1 localhost 1.2.3.4 service.domain.com service In response to hostnamectl suggestions piling up in comments: it is not mandatory, nor exhaustive.
It can be used as a replacement for step 1 & 2, IF you OS ships with systemd. Whereas the steps given above are valid regardless of systemd being present (pclinuxos, devuan, . ).
Both those conf files say DO NOT EDIT THIS FILE BY HAND — YOUR CHANGES WILL BE OVERWRITTEN on my server (same version).
Don’t be fooled by the fact that the «DO NOT EDIT» warning appears in /etc/resolvconf/resolv.conf.d/head . Everything in the head file is prepended to the resulting /etc/resolv.conf output file, so that’s why the warning is in there, so that it shows up in the final result. Threw me for a loop at first.
This doesn’t seem to apply to 18.04 LTS — there’s no such file /etc/resolvconf/resolv.conf.d/head and there’s no such utility resolvconf .
Note also that if you use AWS you’ll also need to preserve the hostname after reboots — sudo nano /etc/cloud/cloud.cfg update preserve_hostname: true (default is false ).
127.0.0.1 hostname.domain.com hostname localhost MUST HAVE SINGLE HOSTNAME after FQDN in /etc/hosts file. Works fine on Ubuntu 18.04.1 and all other versions. On EC2 and elsewhere.
Didn’t mess with resolve file or anything else.
That shows hostname in shell and then has the FQDN when you need it.
@MikeCiffone Technically, hostname should not contain the domain name — i.e. should not be FQDN. Many deployments do it, but it should not be done that way. Note that in-kernel hostname under Linux after 1.0 is restricted to 64 characters (see man 2 sethostname ) because that’s the value of HOST_NAME_MAX . (Until 1.0 it was mere 8 bytes.)
@bfontaine You don’t have to care about any of the reasons I’ll state — most of my hosts were configured with hostname=fqdn most of the time, and they worked. One reason is that your FQDN, not shortname, is then limited to 63ch ( HOST_NAME_MAX ). Another is that molly-guard will require you to type fqdn, not the shortname. Another is that hostname CLI prints out the full FQDN, not just hostname -f . Another is that some software might print out FQDN in place of shortname, or append the domain a second time to the FQDN (i.e. foo.example.org.example.org instead of foo.example.org ).
You can, of course, dismiss all of these as hypotheticals — but I feel correctness of having the hostname contain just, well, the hostname is more correct and professional.
Instructions written against Ubuntu 18.04.3 LTS (bionic)
sudo hostnamectl set-hostname server1 Check result by running hostnamectl :
root@www:/# hostnamectl Static hostname: server1 Change the domain via new network manager, Netplan, by editing /etc/netplan/01-netcfg.yaml and changing the search parameter:
sudoedit /etc/netplan/01-netcfg.yaml # This file describes the network interfaces available on your system # For more information, see netplan(5). network: version: 2 renderer: networkd ethernets: eth0: dhcp4: yes nameservers: search: [ domain.org ] Test changes by logging in a second time, and running sudo netplan try in one of the sessions and checking settings in the other:
# netplan try Do you want to keep these settings? Press ENTER before the timeout to accept the new configuration Changes will revert in 97 seconds Configuration accepted. # systemd-resolve --status . Link 2 (eth0) Current Scopes: DNS LLMNR setting: yes MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no DNS Servers: 8.8.8.8 8.8.4.4 DNS Domain: domain.org # cat /etc/resolv.conf . nameserver 127.0.0.53 options edns0 search domain.org # hostname -f server1.domain.org It all is well, press ENTER at the sudo netplan try prompt to make things permanent.
[…] You cannot change the FQDN with hostname or dnsdomainname. The recommended method of setting the FQDN is to make the hostname be an alias for the fully qualified name using /etc/hosts, DNS, or NIS. For example, if the hostname was "ursula", one might have a line in /etc/hosts which reads 127.0.1.1 ursula.example.com ursula Technically: The FQDN is the name getaddrinfo(3) returns for the host name returned by gethostname(2). The DNS domain name is the part after the first dot. Therefore it depends on the configuration of the resolver (usually in /etc/host.conf) how you can change it. Usually the hosts file is parsed before DNS or NIS, so it is most common to change the FQDN in /etc/hosts. If a machine has multiple network interfaces/addresses or is used in a mobile environment, then it may either have multiple FQDNs/domain names or none at all. Therefore avoid using hostname --fqdn, hostname --domain and dnsdomainname. hostname --ip- address is subject to the same limitations so it should be avoided as well. […] This was kindly pointed out by poige in another thread and is exactly what Lutz proposed here.
You should not put your fqdn into /etc/hostname .
I tried to change my domain entry from myhome.local to myhome.lan I had to edit the /etc/hosts file and the /etc/network/interfaces file. My /etc/hosts file now looks like:
127.0.0.1 localhost 192.168.3.2 server.myhome.lan server and my /etc/network/interfaces file now looks like:
# This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto enp2s0 iface enp2s0 inet static address 192.168.3.2 netmask 255.255.255.0 network 192.168.3.0 broadcast 192.168.3.255 gateway 192.168.3.1 # dns-* options are implemented by the resolvconf package, if installed dns-nameservers 192.168.3.1 dns-search myhome.lan How to Edit Hosts File on Linux Mint 21
Host file of Linux mint primarily maps the IP address with the domain names of the system thus making it useful for various purposes which include blocking a website and accessing any computer remotely. If you are unaware of how to edit a host file in your Linux Mint 21 and want to use it for multiple purposes, then read this guide.
What Is the Purpose of Hosts File in Linux Mint 21
Host file as mentioned above contains the IP addresses and hostname of the Linux system, but there are multiple uses of host file and those are:
- Blocking any websites
- Remotely accessing any Alias
- Blocking advertisers and trackers
- Testing an application
- Adding or blocking specific networks
How to Edit the Hosts File in Linux Mint 21
The process of editing the host file of Linux Mint 21 is quite easy; open the host file on your Linux Mint 21 by using any terminal-based text editor, for example, nano:
Now edit the host file by entering the data like IP addresses and host names for the connections you either want to block or access.
How to Block a Website through Hosts File
When it comes to security or parental control hosts file plays a crucial role as it can be used to block unwanted websites. The process of blocking a website is mentioned below:
For instance, if you want to block YouTube then use:
Next save the file and open the website on the browser of Linux Mint to see if the site is blocked or not:
Conclusion
Host files in an operating system generally contain the IP address and the domain name of that system, there are multiple uses of a host file which can be achieved by editing it and it can be done by stating its path with nano command.
About the author
Aaliyan Javaid
I am an electrical engineer and a technical blogger. My keen interest in embedded systems has led me to write and share my knowledge about them.
How To Get Host Name and Domain Name Of Linux?
Host name is the identifier of a system in the network. Host name can be get with different ways in Linux. Host name is generally put in the /etc/hostname file.
Get Host name By Echoing Host name File
Host name information is stored in a file /etc/hostname . So we can simple print the host name to the terminal with echo command like below.
Get Host name With hostname Command
We can get host name with hostname command. This will only list host name and will not print domain related information.
Get Fully Qualified Host name
We can get fully qualified host name which provides full name with domain information.
Hostname File
Host name file /etc/hostname will only provide host name with fully qualified domain name. There will any no other data in this file.
Change Host name
As the hostname is stored in the /etc/hostname file we can change the hostname by editing this file. We will set the hostname as ubu1 with the following echo command. Keep in mind that in order to change /etc/hostname file we require root privileges which can be get with the sudo command.
$ sudo echo "ubu1" > /etc/hostname
Get Domain Name
Domain name information is about the systems network configuration.