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So the first thing that you need to
know is how to apply non persistent network

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configuration on servers. IP address configuration is normally
set statically using tools like NMCLI or NMTUI

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on Red Hat on workstations, IP address configuration
is typically handed out by a DHCP server

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for troubleshooting purposes. The IP command
is used to set runtime network configuration.

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The important task is that you know
how to get your IP configuration and

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sometimes for analyzing. It's useful if
you can do it manually as well.

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So how does that work? Well,
you need to use the right tools.

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Runtime networking is not persistent, but it
is useful for analyzing what is going on.

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In the past, ifconfig was used.
Nowadays ifconfig is obsolete, you should not

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use it because it uses outdated
methods for addressing and displaying networking.

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And for that reason
it doesn't display accurate information.

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The nettools package which contains ifconfig
is not even installed on many modern

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distributions anymore. But sometimes you will
still find it because of dependency requirements.

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The main utility to check and
manage networking is the IP utility.

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Now let me run a demo
in which we can see some

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of the most common tasks
with this utility for your convenience.

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The demo is
also on the slide.

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So I am going to start using sudo ipa,
which is short for IP address show and that

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is showing that my network interface is called
ens160 and I have an INET address on 192.168.29.14.1.

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So I am going to
use sudo ip addr add

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to add an IP
address to my network device.

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Dev is specifying which network device and that
will be ENS160 and setting it to 10.0.0.1024.

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Next I'm going
to do what?

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Well, I'm going to show
you sudo IP a that

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is showing that we now
have this secondary IP address.

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I can use sudo IP
link set ens160 down. That

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will bring my network interface
down. IPA is showing that

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the status of the interface
is now set to down.

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That is temporarily disabling it. If you don't like
that too much, don't forget to switch it up again.

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How about sudo
IP route show?

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Well, that is showing the
routing table and in this routing

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table I can see my
default route being set to 192.168.29.2.

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I'm not going to use
IP route at default via

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10.0.0.1 because I don't like
to change my default router.

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If I change it, I can't
get out to the Internet anymore.