5-6 noob questions about the network (carefully! the extreme degree of incompetence of the author!)?

Question

Active Directory

What we have:

• a fleet of windows computers, some of which are connected via WiFi (network-network, Client mode),
  
• virtualized servers with hopes for a domain,
  
• unstable connection.
  
• And yes, I don't understand how the subnet mask works.
  

Let's get started:

1. Subnet mask Well, yes, somehow I didn’t work out with it.
   It's time to expand 192.168.0.1-255 to 1.255. As I understand it, you need to change the mask from 255.255.255.0 to 255.255.254.0, right?
   Made. But hallucinations begin in the network: the loss of the network in general and the Internet in particular (which is distributed (together with IP) via D-Link DIR-300 - what can be replaced (inexpensive and reliable). I thought about Ubuntu + squid). Computers on the network are no longer displayed (by network name), there is access to them by IP.
   
2. Seagate GoFlex Home“The previous admin” © as a file-sharing installed a household friend Seagate GoFlex Home - with one hard, terribly slow, but (pah-pah) still working. Naturally, you have to backup every night. But now a little about that, but again about the subnet mask.
   In the admin panel of this device, in the network settings, only the following options are given:
   
   • 255.255.255.0
     
   • 255.255.0.0
     
   • 255.0.0.0
     
   • well, what is there: 0.0.0.0.
     
   So how to combine this with 255.255.254.0?
   
3. DHCP Again, the question has to do with masks.
   I changed the settings on the same D-link or on the Windows Server dhcp server. Is it possible to initiate an update of network parameters for client systems (besides turning off the electricity in the office :)? I registered, for example, a new gateway and dns-nicknames, pressed the button - all computers were notified, and everything changed. And there is no need to wait for the morning (those who turn off the computer at night) or until someone comes up with the words “it works !!”.
   
4. Servers We have two servers: one based on Xeon E5620 2.4 + 8Gb RAM + 1Tb (RAID1, SAS), the second one is 2x Xeon E5-2650 + 32Gb + 2Tb (RAID1, SAS). Windows Hyper-V Server 2012 got up on both of them with my efforts, on them - Windows Server 2012 Std with domain controllers + DNS + DHCP (disabled for now, the second in reserve).
   The 1st, in addition to two built-in network sockets, also has a separate Intel server card (I don’t remember the model).
   Well, you still need to load the gateway (apparently Ubuntu + squid), file storage, MS SQL Server (express or standart), possibly KMS, 1C 7.7 and 8.2 file bases, OpenFire + somehow back it all up on these pieces of iron.
   What is the best way to distribute these services among servers, is it necessary to create additional virtual machines (for Ubuntu - of course :), and which version is better to install - 2012 or 2008R2?
   
5. Wireless networksDue to the topological features, the computer park is divided into several parts: the main office (all wired, of course), a group of computers (up to 10) at 30 m (now WiFi, it is planned to lay a cable), and a group (up to 5 at the moment) - in 1 -2 km (WiFi).
   The WiFi network is built on TP-Link WA801 (as an AP) + 701 (as a Client or Bridge with AP) with external whip antennas on the "receiver" and aimed at the "transmitter". There is almost direct line of sight. "Practically" - because at any moment a Kamaz can get in the way or a metal trailer can grow.
   There is such a problem: from time to time the connection on the clients is lost, only restarting the access points helps, followed by restarting the network interfaces on the computers. And with static IPs, there is usually no such problem. It turns out that the access points do not have time to connect with each other, as Windows already assigns its IPs, on which you will not go far.
   Such a crutch can work uninterruptedly for several days, or it can fly off every hour - I have not identified the dependence. And visibility, it seems, has nothing to do with it, since there is a signal at the point (11-15 dB, as the point itself says).
   And if it is possible and even necessary to throw a cable to the nearest group, then I can’t quite imagine what to do with the distant ones. Technically, it is possible to conduct it along electric poles, but with such a distance, the signal will die to hell.
   

I really hope for your help and look forward to answers to such <:)>quivering</:)> questions.
UPD0: I
forgot one of the main questions about AD:
6. Transferring profiles
How to make sure that after entering a computer into a domain and logging in with a domain username, the user would see everything that was before. In general, how to transfer a user from a local computer to a domain with all its tinsel and with minimal loss of nerve cells - both for him (the user) and me (enikey).

Answer 1

Answers:
points 1 and 2. Subnet mask.
The following extension is done correctly (/23 or 255.255.254.0).
Perhaps the problems arose due to the fact that on the local computer, from where the router was configured, the network remained with the same mask (255.255.255.0) with all the ensuing consequences in the form of different broadcasts. But this is an assumption.
Not all equipment can work with CIDR masks. These are the masks that are between 255.0.0.0, 255.255.0.0, 255.255.255.0. At me even linksys one was not able.
Therefore, as an option, use the mask / 16 (255.255.0.0)
3. DHCP
No way, if the device received a lease, then until the next. updates, it does not contact the DHCP server.
There is an option to connect or approach each client and restart the network card (I don’t remember how it looks in Windows).
4. Servers
About the gateway: it is quite possible, but it depends on how you access the Internet.
About the database and backups: it is not recommended to virtualize the database, there is very strong I / O and additional. abstraction layer will get in the way.
About the version: it worked for me both in 2012 and 2008R2, but no further than the tests. The combat network runs on VmWare ESXi 5.1. It seems to me that 2012 will be better, because the bugs identified in 2008R2 have been fixed and new features (well, bugs, of course) have been added.
About backups: ideally, allocate a separate machine for this good cause, or better a NAS, which can do a lot.
5. Wi-fi
Specify: do you use WPS at points?
About KAMAZ: you can get hold of repeaters or AP in repeater mode. For antennas: you can use assemblies with amplifiers.

Answer 2

To begin with, everywhere (including all network equipment), write the mask 255.255.0.0, this will allow you to configure the network more flexibly and correctly.

Answer 3

The solution has already been written, but I have a comment.
Are you sure that more than 254 computers in one broadcast domain is normal?
In a good way, it is necessary not to expand the subnet mask, but to beat the network into parts and configure routing.

Answer 4

DHCP
needs to reset the lease on the server in order for clients to renew and take on new addresses. in different systems in different ways.

Answer 5

Renew lease on Windows:

ipconfig /renew

Answer 6

Regarding the last point: either they suffer with wireless, or give up optics, on each side there is a media converter. A medic can cost from 2,500 rubles a piece, plus a cable. Find a provider with a tool to help finish the optics (because of one line, buying a set seems to be unnecessary). The main problem is to throw the cable itself, a good self-supporting one is expensive, and a simple inexpensive one is not intended for the street. Probably, you can try to shove it into the corrugation, maybe it will survive there ...

Answer 7

6. For Windows 7 - Start -> All Programs -> System Tools -> Windows Easy Transfer. Migrates one user's profile to another

Answer 8

To migrate / transfer data with all the "consequences" / settings from one domain to another or from a group to a domain, and so on, the ProfWiz program is great.
I used it myself when I transferred 150 machines from one domain to another. Convenient and fast. the program weighs less than 1 MB)