How to change hostname on ubuntu server?

Question

linux

Hello. There is a server on ubuntu server.
Result of hostname command: Jus
/etc/hosts

127.0.0.1 localhost
127.0.1.1 Jus

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

But services like 2ip.ru say my computer name looks like 1.2.3.4.5.bla.superprovider.com
What am I doing or could be doing wrong?

Answer 1

The hostname command will show you the local name of your system, what is written in /etc/hostname
2ip.ru shows you nothing more than a reverse record to your ip address ( PTR The
question is, for what purpose do you want to change the hostname?