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- Another part of networking
is the host identity.

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So, for correct operations,
it's important that the

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Linux hosts have the right name set.

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Also, host name resolution
is often a heart requirement.

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As often reversed host
name lookups are performed

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in communication between hosts.

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The main command to manage
hostnames is hostnamectl

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and you can configure
the /et/hosts file with

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the appropriate hostname lookup settings.

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Let me demonstrate.

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So, to start it I'm using hostname,

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hostname is the old command.

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Hostnamectl is the new command

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and host main- hostnamectl
status, for instance,

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is showing you the static
hostname and so much more.

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So, the static hostname here
seems to be just centos.

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Nice thing about hostnamectl
is that it is also

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telling you information
about the operating system

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and much more.

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Now, if you use sudo hostnamectl,

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then you can actually set the hostname.

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So, hostname centos.example.com.

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And now if I use hostnamectl status again,

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then we can see that this
hostname has actually been set.

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It's up to you.

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If you use an FQDN, a Fully
Qualified Domain Name.

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That includes DNS information
as in hostname.example.com

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or a short hostname.

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Now, in order to enable hostname resolving

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there's a configuration file ITC hosts

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and I'm going to edit ITC hosts right now.

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You can see that by default
it only has information

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about localhost.

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I am going to add 192, 168, 29, 141

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for my centos.example.com.

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That's the long name and I'm
also including the short name,

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192, 168, 29, 142, for
the ubuntu.example.com

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and the short name ubuntu.

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Now, what is the result?

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The result is at this
point I can use utilities

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like ping to verify
connectivity with my ubuntuhost.

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ITC host is convenient, it's
for local hostname resolution.

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If you wanna be able to
do hostname resolution

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on internet hosts, that
is the system called DNS,

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but DNS is not something that
we are going to configure

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in this course.