Week 17: Day 048 - Network Naming

Welcome to my new format of doing blog entries on Network+. You should expect to see up to nine posts until the end of the month on this. I think this will all be done by the end of January, which is great for me. I skipped a week of blog posts since I was really busy learning command line for Linux. This chapter is about Network Naming. You have a name for your network as a convenience, and to be able to communicate over the internet, there is a translation that takes place so the network can switch a regular IP to a domain and vice versa. This is called DNS, which is the first topic of coverage; let's get right into it.

Domain Name System (DNS) is a name resolution system which translates IPs into domain names, so I don't have to go on http://93.325.525 to open a webpage. In the early days of TCP/IP a system called HOSTS was used. A HOSTS file had a list of IPs of networks on the internet. There weren't that many computers back then. Here's an example of what it looks like:

192.168.2.1     fred
201.32.16.4     school2
123.21.44.16   server

The HOSTS file on every system was update at 2 AM every morning. If you wanted to contact fred, HOSTS would just look for his name, and contact him. When the internet grew, it became impractical. Important thing to note the # on HOSTS file meant the line would be a comment, kind of like Python does. Long story short, to see how it works, ping a random website in your CMD (command prompt) and take the IP of what you're pinging, put it into a text editor, put a name beside it like, "bob", then save it as a HOSTS file. Afterwards type "ping bob" into cmd, and it will show ping that address.

The way Domain Name System (DNS) was created, was through the need to replace HOSTS. What ended up being the normal DNS was a method in which the top dog DNS systems delegated jobs to other ones which delegated jobs to ones below them. As you can see, it's very bureaucratical. These systems run a special program and are called, "DNS servers". The top dog ones are super computers around the world, which work as a team known collectively as "DNS Root Servers". DNS root has the complete name resolution table, while the resolution work is delegated to other DNS servers. Under the DNS root, the next part of the hierarchy is "Top-Level Domain" (TLD) names. They are the famous .com, .org, .net, etc. names at the end of a URL. Then under that is Second-level DNS which support individual computers. In essence what happens is that the domain is masking the IP address of the individual, and it is at second-level in which this happens. Now in terms of the DNS hierarchical name space, it's basically a tree structure which contains all possible names within a single system. HOSTS used "flat name space", which is just a big unorganized list. I already understand the hierarchical system, so no need to go over that (but if I did, pg. 321-323). Now in terms of how the name space works, it works a lot like the file system on a computer. I've been playing around with Terminal in my other course, and it's taught me a lot about hierarchical file systems on Linux. This is essentially the same on Windows. But in the world of DNS, you start out with the "root", then the "domain", and then the "host names". If you wanted to use DNS in your TCP/IP network you could, it's not exclusive to the internet. That would be called an "intranet". Regardless, the DNS naming convention is the opposite to that of a computer. The complete DNS name + host and domain is called "Fully Qualified Domain Name" (FQDN) which is written with the root on the far right, followed by domains left of the root, and host names on far left. So basically on Windows if you went for example C:\Program Files\Steam\SteamApps it would be the complete opposite in the world of DNS instead it would be reversed to SteamApps/Steam/Program Files/C: which may seem weird, but deal with it!

Then there's the "name servers". Here are the three key ones:
- DNS Server: A DNS server is a computer running DNS server software
- Zone: A zone is a container for a single domain that gets filled with records.
- Record: A record is a line in the zone data that maps an FQDN to an IP address.

Systems with DNS server software contain DNS information. A network usually has one DNS server for the entire network. On Pg. 327 there is an example of authoritative DNS server which lists all host names on the domain and their corresponding IP addresses.You can have a single DNS server as authoritative. Every DNS server knows the name and address of the "Start of Authority" (SOA). If Mikes-PC.Support.Houston needs the IP address of Server1.Dallas then the network has to choose an authoritative DNS server. Say that DNS1.Dallas is the authoritative for all Dallas domains and DNS.1 is in charge of all Houston domains. As root, Houston server has a listing for SOA in the Dallas domain, but does not know the IP address for every system on it. The requesting sytem will ask the Dallas DNS server for the IP address of the system it needs. There are advantages to the hierarchy, as almost all web servers are called www. only the DNS naming appends domain names to the server names. No to machines have the same FQDN because it must fit within the worldwide hierarchy.

To access the internet you don't have to use DNS. It makes things easier to do, however. Browsers accept urls like www.google.com, but it converts it into an IP to access the webpage. Moving on, to broadcast for name resolution, the host sends a message to all machines on the network, requesting a respsonse from another system on another network. The broadcast stops at the router, since routers don't forward broadcasts. Now the final way of resolving a name to an IP address is, of course, to use DNS. To request the IP address of www.micrsofot.com, for example, your PC needs the IP address of its DNS server. You have to enter its DNS info int your system, by using the "TCP/IPv4 Properties" dialog box. I've used it before. Enter what Mike has down on pg. 332 and see what happens! Every OS has a tool like the one on Microsoft. On Ubuntu it's "Network Configuration Utility". You can verify your settings on Command Prompt through "ipconfig /all" and on Linux with "cat /etc/resolv.conf".

The DNS server receives this request for the IP of www.microsoft.com from your client. Your DNS server will check the cache of a previous FQDN to see if www.microsoft.com is there. Let's say it isn't. Your DNS server needs to find it. It may not know the address of for www.microsoft.com but it knows 12 root name server operators. Those know all the addresses for top level domains. The root servers will send your DNS server an IP address for a .com server. But that .com DNS server doesn't know the address for www.microsoft.com either! But it knows the IP of just microsoft.com. Finally, we know that microsoft.com will know the IP address to www.microsoft.com (finally.)

I'm skipping a section of the chapter which doesn't cover much for the test. Let's go straight to Troubleshooting DNS. Most DNS problems result from an issue with the client. How do we know? DNS servers rarely go down. Everything you do on an IP network depends on DNS to find the right system to communicate to for whatever job an application needs to do. FTP clients use DNS for their servers, and web browsers use DNS to find web servers. The first clue to expect the rare occasion in which a DNS server is at fault, is when you see a "server not found" error. To test, flush out DNS caches by typing into cmd "ipconfig /flushdns". If you can't use your web browser for testing, just use the "ping" command. Run ping from cmd, followed by a famous website. An example would be, "www.google,com". If you get a "request timed out" message, that's okay, you just want to see if the DNS is resolving FQDNs into IP addresses. If you get a "server not found" error, you'll need to pign again with just an IP address. The IP for Google is 74.125.95.99 try memorizing that! If ping works with the IP address, but not the website, then it's a DNS problem! Simple.

In addition, NetBIOS is a system created by Microsoft for Windows (older ones), and was invented in the 80s. Basically Microsoft kept adapting their NetBIOS to work with TCP/IP, and made it DNS-compatible. To reduce overhead, they created a special text file called LMHOSTS, which is like Hosts except it uses "Windows Internet Name Service" (WINS) for name resolution. Two reasons to use a WINS server would be to reduce overhead broadcasts, and to enable NetBIOS name resolution across routers. Why routers? Well routers kill broadcasts, so they have that in common. To keep Windows systems connected to your WINS server from broadcasting, you'd use a WINS "proxy agent", to forward WINS broadcasts to the WINS server. To configure the WINS client, you only need to configure the IP address of a WINS server in its WINS settings under Network Properties. Then Windows will just look for the WINS server to register its NetBIOS name. I'll skip the troubleshooting bit for this, since it's unimportant to the test.

Finally, here's how to diagnose TCP/IP networks:

1. Diagnose the NIC by pinging the loopback, typing into cmd: "ping 127.0.0.1" or "ping localhost"

2. Diagnose locally.

3. Check IP address and Subnet Mask

4. Run netstat by typing into cmd: "netstat"

5. Run netstat -s (same as before except with -s modifier)

6. Diagnose to the gateway.

7. Diagnose to the Internet.

Completion Status: 52.5%
Pages Left:
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Questions:
1. NetBIOS uses what type of name space?

2. The DNS root director is represented by what symbol?
/ (forward slash)

3. What command do you use to see the DNS cache on a Windows system?
ipconfig /displaydns

4. The users on your network haven't been able to connect to the server for 30 minutes. You check and reboot the server, but you're unable to ping either its own loopback address or any of your client systems. What should you do?
Replace the NIC, cause it sucks and it failed.

5.  A user calls to say she can't see the other systems on the network when she looks in My Network Places. You are not using NetBIOS. What are your first two troubleshooting steps? (Select Two)
Ping the loopback address.
Ping several neighboring systems using both DNS names and IP addresses.

6. What is checked first when trying to resolve an FQDN to an IP address?
HOSTS file

7. Which type of DNS record is used by mail servers to determine where to send e-mail?
MX record

8. Which command enables you to eliminate DNS cache?
ipconfig /flushdns

9. Which tool enables you to query the functions of a DNS server?
nslookup

10. Where does a DNS server store the IP addresses and FQDNs for the computers within a domain?
Forward lookup zone.

Week 17: Day 047 - Guide to Installing VirtualBox on CentOS

Today, I finished my last quiz on the Command Line. I'm back here full time. However, today I just wanted to tell you how to install VirtualBox on CentOS. Funny enough, we may not even need it! CentOS comes with something similar to VirtualBox, and its simply called "Boxes". I'll try both of them.

To install VirtualBox on CentOS through Terminal, go to this directory by typing:

cd /etc/yum.repos.d


Add the repository by typing:

wget http://download.virtualbox.org/virtualbox/rpm/rhel/virtualbox.repo


Then you'll want to type this, since I didn't use DKMS:

yum groupinstall "Development Tools" yum install kernel-devel

(Note: If your kernel is updated, then you don't really need to do the second command)

Then finally, for the grand finale... the installation! You must do the honor's and type:

yum search VirtualBox
yum install (Latest Version of VirtualBox)

Then you're done! I hope this guide helped.

Week 16: Day 046 - TCP/IP Applications #4

Hello, today is my last entry on this chapter. This is also the last day I will be doing this format for my Network+ blog entries. Next time I will dedicate an entire entry to a chapter overview, much easier, less time taken up. Today I'll be focusing on more clients and servers. Now let's start it off.

The Electronic Mail (e-mail) was part of the Internet revolution for many obvious reasons. It allowed people to communicate with each other much fast. It's usually offered by ISPs for free, but let's be honest, who uses those?! Everyone's using G-Mail, Outlook, and even Y-Mail these days. Now what it consists of are e-mail clients and servers. We slightly touched on this in an earlier entry. When you receive an e-mail it's put into your inbox. The e-mail applications have some unique abilities, such as alerting you when you get an email, or deleting emails that you already have stored in your computer.

There are several application-level protocols which e-mail programs use to send and receive info and documents. The Simple Mail Transfer Protocol (SMTP) sends your e-mails, while travelling on the TCP port 25.  Post Office Protocol version 3 (POP3) which is one of two applications which receive e-mails from the SMTP servers. It uses port 110, and is the most used. Then there's Internet Message Access Protocol version 4 (IMAP4) which is the alternative to POP3. It uses TCP port 143, and has some features not in POP3. An example is that it enables you to search for keywords through your e-mail, and it supports folders to organize your e-mails. There are alternatives to those applications. Most of them are web-based. As we all know, there's G-Mail and Outlook, and Yahool Mail as I said earlier. The benefits of those services are obvious, and I do not need to explain them.

The e-mail server world is more fragmented than web servers. The most used is "sendmail" which is used on UNIX/Linux Operating Sytsems. However, similarly to Apache sendmail lacks an interface. THere are many third party interfaces though, like Webmin. To run Sendmail you need POP3 or IMAP4 server program to support the e-mail clients. Microsoft have their own e-mail server, "Microsoft Exchange Server", which runs solely on Windows. It's both SMTP and POP3 in one. As you can imagine e-mail servers accept incoming mail. This is called the mailbox, as it would in real life. The e-mail server is like a post office, it sorts the messages. Setting up and running e-mail servers can be tedious, as it needs to be planned and secured. It's getting easier, with GUIs available for the servers, and even the command-line based ones are getting easier too.

Then there's the e-mail client which is the program which sends out e-mails we type, while receiving and organizing those coming in from the e-mail server. With that said, e-mail clients communicate with the e-mail server to send the mail to their targeted recipient. To configure these clients, you just get the e-mail server's domain name and mailbox user's domain name. You'll probably notice that this is not really relevant in today's world to the average user, since they use web-based e-mails which take care of that for them. Much of this is now nullified because of that.

On a different topic, there's the File Transfer Protocol (FTP) which is used for transferring files over the internet. The benefits of this protocol are that its secure (big one) and that it's fast and reliable, more so than HTTP. The ports used for FTP are TCP port 21 and 20, but only uses 21 by default. An FTP site is either secure or not, depending on what the creator decided. It can have a user name and password to access and transfer, or not have one at all. The FTP server does all the storing of files, accepting connections, verifying passwords, and the actual transferring. All the client really does, is access the FTP site, and downloads the files from there. The reason why people need FTP servers, is if they want to share files with each other, but NOT through the internet. FTP isn't as secure as described though, because data transfers are not encrypted. However, there is the ability to add usernames and passwords, along with anonymous logins. Usually there is a limit on how many clients your server will support. This is just to prevent people from flooding your server and taking up bandwidth. In terms of the FTP clients, it accesses the FTP server through a website, command line, or a special FTP application. Best option is to use a dedicated FTP client, one of their special apps.

Finally, there are two ways of transferring data over FTP. This is "active" and "passive". Usually FTP uses the active process. When your client sends an FTP request, it goes through port 21, But remember there's also port 20 which is allocated for FTP. It uses an ephemeral port as a reception for data coming from the server, and port 20 as a source port. Basically, active FTP is great unless your router is using NAT. Because the client didn't initiate the incoming port 20, the NAT router doesn't know where the send the incoming packets. The solution to this is passive FTP which will have the server send back a random port number, telling the client which port it's listening on for data requests. The client will then send the data on the specified port of the FTP server. Only then will NAT know where to send the packet. That's where the chapter ends. Thanks for reading and goodbye.

P.S. Here is a table of Internet Application ports:

HTTP: 80
HTTPS; 443
Telnet: 23
SSH: 22
SMTP: 25
POP3: 110
IMAP4: 143
FTP: 20/21 or just 21 (passive)
TFTP: 69 (haha) (UDP)

Completion Status: 46%
Pages Left:
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- Chapter: 0 pages

Week 16: Day 045 - TCP/IP Applications #3

Hello everybody, today we're gonna continue Network+. I was never actually able to finish this blog post before Winter Break, but this is what I typed before leaving for break: "Just today and tomorrow until break. My plans are to watch Star Wars: The Force Awakens on the 22nd (big fan of Star Wars) with my friends, and then do the routine Christmas activities. In addition to that, on the 29th, I'm gonna come back here with Marco and learn some Python with Mr. Kevin Cole. Can't wait!, let's get started." We never actually came back to the Career Center during break, since the building's open hours were a bit dodgy I guess. One thing I'll be happy to repeat though is, "let's get started"!

I read the stuff that I didn't go over last class, (Note To Self: it was really useful, so read it again, future version of myself!) so I'm good on that. Now it's time to talk about the TCP/IP Applications themselves. Let's start with the World Wide Web. Many would be inclined to say that the Internet = The Web. However, this is a common fallacy, that is not true at all. The Internet supports the Web but it is not the web. The Web is comprised of servers which store documents using hypertext Markup Language (HTML). HTML has been around for quite a while, but it has been updated several times. The latest version of HTML is HTML 5. What web browsers do is request HTML pages from the Web servers, so when they receive them, they open them. When you enter http:// and the IP address of the Web server, it will access the web page. No one does that though haha. Doing text addresses like "google.com" is much easier. As I already know the default port for HTML is port 80 for TCP. However, it's kind of annoying that it doesn't take into account your previous "commands", although there's several applications that take care of that (Ex: Google Chrome will auto-complete your addresses sometimes, based on previous addresses)

When you've finished designing your HTML document, you can share it with the World Wide Web. You can install a Web server into your computer, my friend Marco has done that. Then you'll need to get a public IP address for the computer, and host the web site yourself. However, you could also pay a company to host your web page. There's free web hosts out there, but there are limitations such as ads, and a domain with their companies in it. However, if you wanna get a domain for your website, you may. They typically charge $10 a month (Google lets you get a domain host for $10 a year :D) Now let's dive into what a Web Server is at its core.

What a Web Server is at its core, is a computer which serves Web pages. They will listen on port 80, and fetch the HTML pages that were given to it, and send them off to browsers asking for it. You can run a Web server on any computer, but you'll need to install server software to connect it to the Internet. Microsoft wants people to use their software "Internet Information Services" (IIS). What IIS does, is that it lets you set a connection limit based on bandwidth and memory. This is meant for protecting your network against a malicious attack like a "Denial of Service" (DoS) attack. On Linux the popular option is "Apache HTTP Server" which my friend Marco is using. It serves over 50% of Web sites on the Internet as of 2012. It's so popular not only cause it runs on several operating systems, but also cause it's free! In comparison, Microsoft's  IIS only has 25% of the market share. Apache isn't much, just an executable program with text files. To make it easier, Web admins get add-on graphical user interfaces (GUIs) to make it easier. In third place there's Google Web Server (GWS) which is only really used by Google servers, and has 5% of the market share of Websites. Then web clients are just the programs used to surf the web, a web browser (Ex: Google Chrome, Internet Explorer, Firefox.)

Now let's be clear here, HTTP is not a secure protocol. Any nosy eavesdropper can plug into the network and read the HTTP packets going around. Fake web sites can be used to trick people and steal user names and passwords. For an internet application to be secure it needs:

- Authentication: Usernames and Passwords
- Encryption: Mixing up data so it's unreadable
- Nonrepudiation: Source cannot deny a sent message

The secure counterpart to HTTP is HTTPS which is already something major. Since so many people use the web, it's important to have security. One safeguard is called Secure Sockets Layer (SSL), which is a protocol by Netscape which transmits private docs over the internet. All popular browsers and web sites support SSL. In recent years, SSL has been slowly replaced by Transport Layer Security (TLS) which keeps the same look on your webpage as if it were SSL, and functions the same way, the only difference is that TLS is more secure.

About 40 years ago, the Internet was full of huge computers known as mainframes which were accessed by a terminal (like in the Fallout series.) Operating systems were made up of a simple command line, as the GUI did not exist then. People became lazy and wanted to access the other terminals from their's, so they figured out how to do it. This gave birth to "Telnet" the first network variation on planet Earth. With telnet you can connect to another system from your own terminal using the command line. This still exists today in the variation of ssh. What is that? Well, I've used it before thanks to Marco, it's called "Secure Shell" (SSH) which is basically modern day Telnet, only major difference being encryption. Routers nevertheless still have the ability of using Telnet. The oldest Telnet servers are from UNIX and Linux systems. However the old "telnetd" isn't as important as the Windows version of Telnet. In Windows, telnet is by default disabled as it is as we established, a security threat. As you can see telnet is pretty much gone because of its security fallacies, so you'll find that SSH is the dominant remote protocol service of today.

The Telnet client is the computer which is logging into the remote server. You'll be able to run telnet from the command prompt or terminal, depending on which OS you're on. To activate Telnet on Ubuntu Linux, open terminal and type "telnet (IP of system you want to access)" and it will work. The command-prompt version lacks features, so you'd be better off using PuTTY. Now in terms of configuring the client, you need to give the host name, the user login name and password of the system you're trying to access. You need to have permission of the server when performing these processes. Usually you'll see Telnet used in libraries, since they don't require much internet security.

The Network+ exam will test you on rlogin, RSH, and RCP. There programs from UNIX. The R stands for "remote", and as you can figure these programs let you access other systems remotely.  However, also expected, they don't encrypt data. Here's a summary given by the book:

- Remote Login (rlogin): Works similarly to Telnet. You run the program with the host name of the server, and you connect and run commands like Telnet. Rlogin has an advantage over Telnet, as it can configure it to log in automatically without entering a username and password. It connectes only to UNIX hosts, unlike Telnet. This works over the TCP port 513.

- Remote Shell (RSH): Enables you to send single commands to remote server. Unlike rlogin, which is designed to be used interactively, RSH can be integrated into a script. RSH runs on TCP port 514.

- Remote Copy Protocol (RCP): Provides capability to copy files from and to remote server without needing FTP or NFS (Network File System, UNIX folder sharing system). RCP can also be used in scripts and shares TCP port 514 with RSH.

In conclusion, Telnet has been used for a long time in the TCP world, but because of its lack of security, it's pretty much died and been replaced with SSH. One thing to remember is that SSH uses TCP port 22 while Telnet's port is TCP 23. Next time we'll finish up the chapter, in standard blog format, and afterwards I'll be only doing Chapter Overviews, and perhaps end of the chapter questions. Thanks for reading and goodbye!

Completion Status: 45%
Pages Left:
- Book: 375 pages
- Chapter: 9 pages

Week 16: Day 044 - Linux Essential Tools #1

Hello, today we will be talking about STDs. Not the kind you're thinking of, but what's called "Standard Output" and "Standard Input". I thought I should start this entry humorously, but continuing, there will be coverage on BASH and shells; the symbol STD will be vital.

First, the shell is the working environment for a Linux network admin. In the book the specific shell they talk about is the "bash" shell. The first thing they talk about are aliases. You type in the command "alias (newcommand)=(oldcommand)" and it will rename a command to whatever you want. This is useful when you want to rename a complicated command to a simpler one. Then there's echo, which is pretty self-explanatory. You type "echo (blah whatever)" then it will copy you like one of those parrots, when responding.

Next, let's learn about I/O redirection (uses STDs). An I/O redirection uses this key ">" and to create a new file with information from another one, you would put the name of the command which withholds information, like say "help", and then type that. Then you put ">" and directly after that write a random title for the text document. Once you do that, type "less (whatever the filename is)" and you will see that the data from the help command has copied over to the new document. If you only have one ">" then it will overwrite the document's contained information. If you have two or ">>" then it will simply add on the data to the selected document.

When navigating directories, if you want to reset it to the highest one, type "cd" and it will do as such. To verify that this works type "pwd". Then "ls" will show you the files in that directory. Also to find your history, just type "history" and it will show you your command history. If you type the shortcut of "ctrl-r" then it will look for a command which specifically contains those characters. Also when you look through your command history, there will be numbers to represent the command, and you can type !(number) and it will execute the command. Another short fact from the chapter is the convenience of having bash auto-complete your commands. You can do this by typing the first few characters of the command, then tabbing until your command shows up. The more characters you type, the faster you'll find the command on the account of uniqueness.

Today, I installed vim thanks to Marco's help. Then Marco tested me on how to get "wget" onto the system. I remembered correctly as I did "yum search wget" and found a match. Then I continued by typed "yum install wget" since there was only one available, and it installed it. This is the first time I succeeded it on my own! BY THE WAY, fun fact when reading a document and clicking "v" it will open the document in vim for you to edit. Marco didn't know this, I found out, out of curiosity.

In conclusion, I am not done with the chapter, but I think I'll dedicate time to learning just vim, since it will probably be important for the rest of the textbook. According to Marco and Mr. Elkner it's a very powerful tool, and I should dedicate time to it. Thanks for reading, and goodbye.

Week 16: Day 043 - Installing Red Hat Enterprise Linux Server

Regardless of the polls, this is not a democracy. Today I am starting my Red Hat course, and it's gonna focus on the certification "Red Hat Certified System Administrator". I am excited to get started on this class. However, this begs the question, am I finished with Network+? Of course not! I will continue studying it on my own. My new plan is to do chapter overviews of each one, rather than specifically going through each subject.

If you couldn't already tell, this blog is sort of an introduction to my Red Hat class. Nevertheless, today our teacher Mr. Elkner guided us on how to partition and install Red Hat onto my system. This is not a dual-boot installation however, because we are using Virtual Box! Let me tell you, this Virtual Box thing is something else. Quite the program to use if you're interested in utilizing a new operating system, and not wanting to take risks. By this I mean, not messing up your system and having consequences; all in all, a great thing.

The way we did it, is that Mr. Elkner went onto our computers while we were gone, and put the iso for Red Hat Enterprise Linux Server, kind of like Santa, except he didn't break into our house. Then he directed us through the installation. We unpack the ISO using VirtualBox directly, and it will take it, and create a virtual system. What we were trying to do with this, was create two servers. One with a GUI and one without. Now to do this, we would need two different versions of the ISO. One with the GUI and one without! Haha I said that twice now. Anyways, Mr. Elkner directed us the first time on how to install "Server1".

To do this, start off by giving this virtual machine 20 GB. Once you get into the installer, you must make three different partitions, one called "sda 1" (/boot) with 500 MiB, one called swap with 2 GB, and one which was the actual root (/) which had 10 GB. Now, swap may have had a little more space then specified in the textbook, but we were testing out whether it would work, and it did. The one important thing to note, when you get to a certain point in the installation, it will have "Network" displayed as an option. It will be disabled, which is odd, and you must enable it to make it work as a server. From there, the installation is pretty straightforward.

Then there's "Server2" which is the one without the GUI. For this, Mr. Elkner has not guided us, we have to work together (with my peers) to make it work. This time, we did the exact same process, the installer lets you choose which type of installation you want, this time I chose "minimal" since we don't need a GUI for this. The process is literally the same, nothing for me to add. That basically ended my first assignment, and CHAPTER! Yes, what a short chapter! Don't expect the rest to be like them haha. Thanks for reading, and goodbye.

Review Q/A:


1. You do not want to buy a RHEL license, but you want to create an environment to practice for the exam. Which distribution should you use?
A: CentOS or Scientific Linux.

2. Why can’t you use a 32-bit version of RHEL to prepare for the exam?

A: Because the system is 64-bit.

3. You want to install a minimal system. How much RAM do you need?

A: 512 MB

4. Why is it a good idea to have Internet access on all servers you are installing?

A: To automatically configure the region and timezone you are in.

5. You want to install a virtual machine on a computer that does not have an optical disk drive. What is the easiest alternative to perform the installation?

A: Use a USB drive.

6. Why is it a good idea to install a GUI?

A: Cause it's easier to use.

7. What is the default file system on RHEL 7?

A: XFS

8. Can you install RHEL if you do not have Internet access?

A: Yes.

9. What is the most important feature offered through RHN?

A: Support

10. Which installation pattern should you use if you have a very limited amount of disk space available?

A: Minimal.