`hostname` result is different from “/etc/hostname”!

Question

If I open a terminal windows in my graphical user interface, hostname command result is different from content of /etc/hostname:

me@ZyXEL1:~$ hostname
ZyXEL1
me@ZyXEL1:~$ cat /etc/hostname
N4010
me@ZyXEL1:~$ cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 N4010

# 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

and sudo command shows:

sudo: unable to resolve host ZyXEL1: No such file or directory

In tty1, tty2 and ... the command prompt is me@N4010:~$ instead of wrong one: me@ZyXEL1:~$, but sudo result is same as terminal window:

me@N4010:~$sudo
sudo: unable to resolve host ZyXEL1: No such file or directory

Just for grins,do a 'command hostname' in case your shell aliases are playing with you? Happens by accident sometimes. :) — Charles Merriam, Nov 07 '19 at 04:21
Look at https://unix.stackexchange.com/questions/186859/understand-hostname-and-etc-hosts — Charles Merriam, Nov 07 '19 at 04:23
@Kusalananda My system IP address is obtained via DHCP of my wireless router. But how to find if my hostname is coming via DHCP or not? — PHP Learner, Nov 07 '19 at 08:52
It may have been recorded in a log. Unfortunately I would not know where to start looking on your system. I've noticed that my own laptops sometimes are assigned custom hostnames when I connect to some corporate WiFi networks. — Kusalananda, Nov 07 '19 at 08:57
@Kusalananda I think you are right, the problem is related to my office wireless/modem. Because it is a ZyXEL modem. But what is occurring and how to prevent this problem?! — PHP Learner, Nov 07 '19 at 09:05

score 1 · Answer 1 · answered Nov 07 '19 at 06:00

1

This may happens when you have just changed the hostname in the /etc/hostname. It is not reflected to hostname yet. You can set the hostname by restart the computer or more simply:

hostname ZyXEL1

answered Nov 07 '19 at 06:00

Chieu Nhat Nang

41
3

After restart, the problem disappeared. – PHP Learner Nov 07 '19 at 08:53

`hostname` result is different from “/etc/hostname”!

1 Answers1