Month: March 2015

Publish Print server 2012R2 with CNAME record

Published on in Management, Windows Server by Elvis

As you probably know, there is no real high availability scenario for the print server in Windows Server 2012R2 environment. Many times we need that in case of a single server failure, users can do their job also when situations like this happens.
In these cases, it is possible to reduce the down time of a server deploying the second print server and use DNS CNAME to publish print servers. Anyway, there are negative parts in this solution:

  • DNS needs to be refreshed, so users can point to another server (consider to have short TTL on DNS record)
  • there is no supported way to publish that printers in AD. Publishing printers in AD is done thru computer name (A record) and printer shared name. As we need to publish printer thru CNAME record, this is not possible. There is a workaround with ADSIEDIT and changing published name, but this is not suggested. (I will cover this in a separate post)

Whatever, you can deploy printers with GPO preferences and this is not a so difficult process. You have just to be careful that every user has mapped the right printer (this can be done with GPO preferences filtering).
To create the discussed situation, first you must to have two print servers (in our case we will name them PS1.domain.com and PS2.domain.com). On the first server, you have to install and configure all printers that you need and you can share them, but not publish them in AD. Of course it will work also publishing them in AD, but if a user will choose a printer from AD, the failover will not work for him.
After doing this, you have to create a name and a CNAME record for our print server (I will name it PrintSvr) that point on the first print server. In our example:

CNAME PrintSvr PS1.domain.com TTL = 5 min

Keep TTL time small, because this time is critical when failover occours! Changing TTL it is not necesary if you plan to use Round robin.

With this, we can resolve our PS1 server with the name PrintSvr and you will be able to browse printers with CNAME, but if you try to install them, you will receive an error 0x00000709.

This is because we need some additional registry changes on the print server:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters
DisableStrictNameChecking QWORD 1
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters
OptionalNames MultiString CNAME
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0
BackConnectionHostNames MultiString CNAME
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print
DnsOnWire QWORD 1

The first and the last registry have to be DWORD type if you have Server older than 2012R2
This are all the changes that you need to do. As we changed the registry, do not forget to reboot the server. When everything is completed, you can export the print server configuration from Print Management console to file. This we be useful on the second server.

Print
On the second server, you have just to install the print server role and add the same registry values. After doing this, you can import all printers in the same way as you exported them on the first server. This will import all your printers with exactly the same names and with the same share names. So, there will not be any problem when you will switch the server. Restart the server.
Now you are ready to test the environment. Change the DNS CNAME record in the way that will point to the second server and test if printers still work (of course you can wait that TTL expire or you can flush cache of DNS servers and client where you are testing).
Good work!.

Add Groups and Users to AD with PowerShell

Published on in PowerShell, Windows Server by Elvis

When I have to manage a bigger environment, with many groups and users, I always think to PowerShell. Of course, the first step to work with PowerShell is that you have all users or groups listed in a CSV (or similar) file. The first problem for many administrators is the structure of the CSV and data needed by AD. I want to talk about this, because CSV stands for comma separated value, what means that all fields are separated by comma. Nothing strange or new, but as we know also AD structure is using commas to delaminate OU’s, domains etc. Because of this, please be careful when you create your CSV file. I prefer to create CSV file with semicolon as delimiter and then all the things are going right.
The second step that I use is to create at maximum three CSV files; one containing new AD groups, the second containing Group nesting (groups that are members of groups) and the last one containing users (Users and groups that have to be members). If you receive that data form other sources, be careful and first just test if all data are correct (if users really exist, if there is no typing error) and after this step begin with the implementation. This could be done with the same script, just delete the lines that contains write actions and export results in a test file for the future control.
Creating a CSV files: For me, the best program to create CSV files is Microsoft Excel. Everyone knows the program in the way that can type names and some data in (not all, you will have to type some attributes yourself) I always use the same structure of CSV and for this reason I never have problem with the script. Fundamentally is first line, where you have to define columns. So there are my columns:

For Groups CSV (New groups to be created):

  • Name – The name of the group
  • DisplayName – Display name of the group
  • Description – Group description (non mandatory)
  • OU – OU, where group will be created (Strucure OU=MyOU,DC=Domain,DC=com)
  • GroupType – Security or Distribution
  • Mail – E-Mail address of the group, if it will exist

For GroupMember CSV (Defines membership of Groups in groups – nesting):

  • Group – Name of the group which will have a group inside
  • Member – Name of the group which will be added as a member

For Members CSV (Define users who will be added to groups):

  • GroupName – Name of the group where users will be added
  • Member – Display Name of the user

This is all that you need. The next step is to test that Names of all users and all names are typed correctly. After you find that all data are OK, just run the scripts. I always use this order: first, I create groups, than I add groups to groups and finally I add Users into groups. This gives me certainty that I always have object that I need created previously.

The script can be downladed here:

GroupsAD.zip.