Simulator for the system administrator or how to surpass their former classmates at an interview

Good day, reader Megamind!

This article does not pretend to how-to, but can be an excellent starting point for future university graduates. It is for those who understand that not only will not surprise, but also will not suit an employer with knowledge from a university.

Here I tried to collect tips on creating a kind of “simulator” for future system administrators, which I, unfortunately, did not receive at the time.
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All newcomers in this area I ask to the table under the cat.
I warn you : there are no configs and configuration manuals.

Immediately apologize for the wildly long title. I just really wanted to convey the meaning of the article so that it would not be missed by those who find it useful.
Now I’ll tell you why it so blinked me into an article.

Prehistory

There were several reasons for writing this article.

One of them is a lot of annoying comments on sites with the meaning “we are all bad. they do not take without experience, but nowhere to take experience. ” As rainwall rightly observed , this is not about IT.

Next: the same "whining" from less experienced colleagues. So we, they say, have begun, but we cannot develop further, because We do not know how it works there. Have you tried? What did you do for hip-hop to get it right? Nothing! This answer offends everyone, but if he is not the truth, he is very close to it.

And if we start to understand this question, then we will understand the root of evil: in order to begin to understand, you need to understand HOW it should work and why.

Attention! Now will be cool swirling thought. Concentrate.

As a novice system administrator should understand what to disassemble before the first place of work? For this, he must understand how it works and why it may be useful. But at the initial stage, we do not know what is used in small companies where they are waiting for us. What to do? Read more.

Here I will talk about typical infrastructure of small companies (in my experience - up to 100 users).
Please do not be discouraged by aspiring to large companies - they do not have many differences and the services described below are also present.

In addition to the story "what have they got there," I will tell you how you can touch it and try to set it up.

Attention! Why is there no “do it this way”, “tune it up by adding it here,” etc.?

It's simple. When preparing a thesis project, I set up a billing for a spherical provider according to the type of this article . Everything turned out great, everything worked, I understood HOW it works and was happy. But after a while the thought struck me: “How did I do it?”. The result is, but what about the methods? Due to the fact that I used copy + paste, I didn’t remember almost anything (except for those moments when it didn’t work). So here I want to tell you what is used and why. And customize? Then customize yourself.

So, let's begin.
This is all just my opinion. The article is informational and not binding. It just seems so to me.

How to feel?

Fortunately for us - there is virtualization. Do not rush to leave with the words "Oh, I will not go on my computer" and "For whom they just write it."

For the so-called “demo-stand”, there is enough PC with a Pentium 4 CPU and above, 4+ GB of RAM (less is possible if you really want it) and about 70 GB of hard disk space.

For this there is a bunch of software. Happy owners of Windows 8 Pro and above (of course with a processor that supports virtualization ) can use Hyper-V. For those who have not yet switched to Windows 8, I would recommend VMware Workstation. You can also use free VirtualBox and Microsoft Virtual PC.

What will we get? The ability to create a small infrastructure with an isolated network.

What to feel ??

Before running through the virtual machines, I would like to explain how to connect them into a network.



As you see, only the gateway will “look out” for us. To do this, we need to configure network adapters in the virtual machine settings in this way:

Gateway - two network cards. One looks at the network card of your PC, the second - the internal network.
All the rest is an internal network.
First we need a domain controller .

It is better to scoop information not from any forums and Wikipedia there, but from Microsoft sites. This is a more reliable source.

Why is it needed? For centralized user and computer management.
When is it needed? Microsoft claims that it is desirable to use it on a network with 6 (or 8, I can not find proofs) PC. In fact, they are trying to move away from working groups at the earliest opportunity. Even when the PC is only 4, but is going to expand over time.

What do we need for this? Windows Server 2008 and higher. On it the following services will be useful to us: Active Directory, DNS, DHCP, DFS. This, so to speak, gentlemanly set.

For tests, you can allocate a virtual machine with 1 GB of RAM and about 30 GB on the hard disk.

What will he do?
Active Directory - store data about your users and computers. And not only.
DNS - match device names to their IP addresses.
DHCP - distribute IP addresses.
DFS - file server. To save resources in small organizations, it is also located on the domain controller.

Now the gateway .
Why is it needed? Everything that can be done on it will be lower.

What do we need for this? Usually for it use * nix systems. Advise anything. Who likes that, so to speak. Beginners advise SUSE Linux Enterprise Server. And stable and convenient. And in the new workplace, you can still meet anything.

There are ready-made solutions, such as PfSense, Vyatta, Zeroshell, m0n0wall, Zentyal, etc.
For him, we have enough 512 MB of RAM and 10 GB of hard disk space.

You can also meet different wishes from the leadership that will need to be implemented on it.

The most common:
"I want to prohibit sitting in contact" - use Squid (you can + SquidGuard)
“I want to see who is sitting where” - SqStat, Sarg, SquidView, etc.
“I want to go from home to a working comp” (TeamViewer is not safe) - OpenVPN and analogues.
“I want to upload files from anywhere” is not a question. We'll do ftp using pure-ftpd, vsftpd, proftpd, etc.
“I want corporate mail in our organization” - zimbra, postfix, etc.

And that is not all. Then all sorts of jabbers, internal portals and the like can go, it all depends on the creativity and imagination of the management and users.

So, we are done with the server side.

But we need to see how this all works. To do this, I advise you to deploy at least one (and preferably 2) virtual desktops .

If only one has enough resources, install Windows 7 Pro. (1 GB of RAM and 20 GB on hdd suffice)
If you get 2 then the OS on them is Windows XP Pro (512 MB of RAM and 10 GB for hdd) and Windows 7 Pro (1 GB of RAM and 20 GB for hdd). Why exactly these? Because they are most common in small organizations.

What can you do with them?

- Joining a domain.
- slaughter them partially access to sites.
- Differentiate access to the file server for different users.
- Practice in applying group policies (there are a lot of opportunities. Often: connecting a file resource as a network drive, installing programs, restricting rights to any tasks, such as managing a firewall).

I think that's enough for the first time.

After you implement all this, you will see how it works, you will encounter some mistakes, you will no longer be afraid to go to the first job in a small company. And the interview will be easier, because there is a feeling of confidence and already a little experience.

PS I would be happy with additions and wishes.
PPS If you have not read my previous article about the beginning of a career in IT - Beginner IT specialist or how not to start your career in IT