Ubuntu Network Connection Files
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Video Transcription
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>> Hello Cybrarians, and welcome back to
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the Linux plus course here at Cybrary.
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I'm your instructor, Rob Gills.
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In today's lesson, we're going to talk about
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network connection files in Ubuntu.
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Upon completion of today's lesson,
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you're going to understand the net plan directory
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and the configuration file there in.
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We're also going to talk about network manager and how
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network manager connections are configured,
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the files that are used to configure those.
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We're also going to learn about DH client,
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but this time in Ubuntu.
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Without further ado, let's go ahead and get
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right to it with some demo time.
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Into today's lesson, as I said,
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we're going to take a look at Ubuntu.
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Let's go ahead and open our terminal window here,
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and we're going to navigate into
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the directory that is called fc net plan.
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Now, the fc net plan directory is going to contain our
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configuration files that we would use
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to set up the network configurations,
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all the different interfaces on our system.
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It's actually just a YAML file.
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YAML is a file syntax that is
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used by Ansible to do configuration.
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We'll touch on Ansible much
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later at the end of the course.
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But for right now, let's just
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go ahead and take a look at this file.
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We're going to go ahead and do a less on this file.
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We can see that this is just using network manager.
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This isn't really super-helpful.
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We'll take a look at network manager in a minute.
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But generally, what you'd find in
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this file would be this syntax.
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You'd have a network line
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and then you have things indented.
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That's how YAML does things.
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Then you would have individual lines to
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configure things on the network.
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For instance, you might have
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an interface name [NOISE] for the system,
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you might also have the DHCP4.
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This should be set to yes or no,
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yes for using DHCP,
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no if we're using a static address.
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If we were using a static address,
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we would see a line that would say
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addresses in this file.
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Then finally, we would also see a line like
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gateway 4 in this file that would
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indicate the default gateway that'll be
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used for static network on the system.
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However, as I said,
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we're not using net plan on this system.
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No. We're using something called network manager.
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Network manager has a different configuration location,
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and you can go into fc
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network manager system connections.
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Now, if we do an LS in this directory,
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we're going to see wire connection one nm connection.
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Now, I can probably try and do
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an LS and just hit "Enter" here
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and what we're going to see is that we
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have these weird backslashes.
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The reason that we're doing this is because
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next is escaping the space.
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It doesn't really know what to do with it.
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Unless it escapes it by putting
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a backslash before every space,
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it won't know how to interpret the file and
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open it correctly. That's why you see that.
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Another way we could do this,
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and so they wouldn't see these weird backslash
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is if we actually just copy this line,
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including these single quotes,
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and then we could do LS on it that way.
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Actually in this case,
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we can't even view it,
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not like we could with that plan,
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we actually need to get elevated privileges.
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We're going to run pseudo edit
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so that we can edit the file.
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We're not actually going to edit it,
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we're just going to view it,
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but we use pseudo edit to get into it.
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I'll type in my user password to
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elevate my privileges and then hit "Enter".
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Now we can see the contents of this file.
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Again, here this is not a lot of information,
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just as we saw in the previous lesson with
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the network scripts directory and the F config ENP0S3,
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we see the same thing here.
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We've got an ID. This is a wire connection,
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is type Ethernet, and we also see the interface name,
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and that's basically it.
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The reason for this is that just like we saw in CentOS,
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on Ubuntu we're just running DHCP.
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We'll see some information in here,
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but certainly not as much information as we would have
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seen in this file if we were running static addressing,
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you would see additional entry lines here that would
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have a value or a key on
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the left-hand side and a value on
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the right-hand side separated by an equal sign.
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For instance, you see address equals and
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then the IP address or
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gateway equals and then the gateway,
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so on and so forth.
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But that's pretty much what we need to know
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for the connection files inside of here.
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Let's quit out of that file with escape, colon, quit.
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What we're going to do now is we're going to take
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a look at the DH client directory.
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If we go into FCDHCP,
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DH client, and what we're going to want to do this,
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let's just do an LS less directory.
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What we can see in
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this directory is all of these DH client files,
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and that's because DHCP in Ubuntu is a lot
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more complex than it is in CentOS.
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In fact, let's do another pseudo edit just in
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case we have to get elevated privileges as well.
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Let's take a look at the DH Client.com file.
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Now what we can see in this file is that by comparison,
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the CentOS is very complicated, very busy.
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Remember in CentOS there's
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only one line in this whole file,
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send DHCP client identifier equals hardware.
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Whereas here we're setting the host name,
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we're going to send the host name over to
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the DHCP client to get the information.
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But we're also going to ask for that to be specified
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using the RFC 3442 classic static routes,
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and we're going to request a whole bunch of
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information back from the DHCP server.
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You can see this on the request line.
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This is all the information that we're trying to
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get back from the DHCP server.
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Just remember that a DH client.com file
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in Ubuntu is significantly more complex.
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It requests a significant amount of information
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more for the DHCP server
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than what you would see in the CentOS system.
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But that brings us to the end of the lesson today.
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In this lesson, we covered
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network connection configuration in
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Ubuntu with net plan and network manager,
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and we also talked about
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Ubuntu's configuration of DHCP
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>> using the DH client file.
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>> Thank you so much for being here and I
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look forward to seeing you in the next lesson.
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