barracuda@barracuda-Lenovo-G550:~$ hostname
barracuda-Lenovo-G550
barracuda@barracuda-Lenovo-G550:~$ sudo hostname
sudo: unable to resolve host barracuda-Lenovo-G550
[sudo] password for barracuda:
barracuda-Lenovo-G550
barracuda@barracuda-Lenovo-G550:~$ sudo hostname
sudo: unable to resolve host barracuda-Lenovo-G550
barracuda-Lenovo-G550
barracuda@barracuda-Lenovo-G550:~$ cat /etc/hosts
127.0.0.1	localhost
::1		barracuda-Lenovo-G550
127.0.1.1	barracuda-Lenovo-G550

# 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-allrouters
barracuda@barracuda-Lenovo-G550:~$ cat /etc/hostname
barracuda-Lenovo-G550
barracuda@barracuda-Lenovo-G550:~$