What are the default settings for '/etc/hosts' and '/etc/hostname'?

Question

I'm using Ubuntu 16.04. I recently started learning DevOps and got a bit crazy with my /etc/hosts and /etc/hostname files. In my frantic attempt to spin up a couple of servers from my local machine I lost track of the default settings, and was just curious to know what they are/were.

As I recall /etc/hosts and /etc/hostname had only one entry, which was the username of my local machine. However I'm not entirely sure.

By any chance does anyone know what the default settings are with a fresh install?

thomasrutter · Accepted Answer · 2023-03-14T12:45:18.807

21

They are based on what you specified as the hostname when you installed: in my below examples "myhostname" is the name you chose. The defaults look a bit like this:

/etc/hostname

myhostname

/etc/hosts

127.0.0.1 localhost
127.0.1.1 myhostname

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

Note I don't put the domain part into /etc/hostname - opinion is divided on whether to do this but I've experienced server software that breaks if a FQDN is in /etc/hostname whereas I've so far had no issues caused by only the hostname there.

edited Mar 14 '23 at 12:45

answered Feb 06 '17 at 03:01

thomasrutter

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and myhostname is in /etc/hostname. – josifoski Sep 26 '18 at 10:58
That's what's there is it not? – thomasrutter Sep 27 '18 at 04:54
2

in 20.04 the `127.0.0.1 localhost` is on first line instead `127.0.1.1 myhostname` – buncis Aug 06 '21 at 20:34
In recent versions the default contents of /etc/hosts have changed, so I've updated the answer, but it hasn't changed in a way that would have any noticeable effect so the older contents would have been fine. The order of items in this doesn't matter either. – thomasrutter Mar 14 '23 at 12:40

What are the default settings for '/etc/hosts' and '/etc/hostname'?

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