sudo: unable to resolve host {hostname}: Temporary failure in name resolution
By John Parsons •
Recently, I tried to run the command, sudo apt-get update and got the Temporary failure in name resolution error. But, after that the command proceeded and went on to update. Should I worried about the error. Below is the complete log:
sudo apt-get update
sudo: unable to resolve host {hostname}: Temporary failure in name resolution
Hit:1 focal InRelease
Get:2 focal-updates InRelease [114 kB]
Get:3 focal-security InRelease [114 kB]
Fetched 6,581 kB in 6s (1,180 kB/s)
Reading package lists... Done 2 Answers
It seems likely that your computer's hostname is not configured correctly. There are two files you should check; /etc/hostname contains just your computer's name, and /etc/hosts will have a line that maps the IP address 127.0.1.1 to your hostname. For example, those files might look like:
username@ubuntu ~ $ cat /etc/hostname
ubuntu
username@ubuntu ~ $ cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 ubuntu
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allroutersIf you don't have those, try adding them -- keep in mind that a hostname should only consist of letters, numbers, and hyphens -- then reboot and see if you have that error again.
I fixed it with:
hostnamectl set-hostname hostname.newdomain.local
