Posts Tagged ‘Kerberos’

How to configure your virtual Domain Controllers and avoid simple mistakes with resulting big problems

So You went ahead and used virtualized Domain Controllers for Your Active Directory domain, congratulations! I am sure You will be happy with the decission, as long as You have a decent virtualizing environment, this will give You both peace of mind, faster recovery and cheaper redundancy.

There is however some special considerations You must do, when You are using virtual Domain Controllers, not to mention, please with sugar on top, Windows Server Active Directorydo NOT P2V/Convert Your physical Domain Controllers to virtual, without at least reading this article!

What areas do we need to consider on a virtual DC?

  • Time synchronization
  • Disk cache
  • Suspend/pausing virtual machine
  • Snapshots and System State backups
  • Performance

Personally I much prefer virtual Domain Controllers, from having a lot of physical ones, but there are some considerations to be made, about perhaps leaving some physical and what features to use on the virtual and what settings to use as well. This article attempts to uncover some of the points to consider, specifically for virtal DC’s. The list is in no way meant to be the only considerations, but is mostly the things that I personally have noticed forgotten in environments I have encountered. Add Your own preferences and research to this and You should be well on Your way to live happily forever with Your virtual DC’s.

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How to fix missing PPTP Interfaces from RRAS console in ISA 2006 and stop a memory leak in the process

All PPTP VPN interfaces in ISA 2006 (sp1) disappeared from the Routing and Remote Access Service console, this problem was a cool problem both because it was challenging but also due to the unexpected results and solutions we found.

The first google attempt at finding a solution told us to try the following workaround – Not recommended!

  • Run the following command: C:\> netsh int ip reset c:\resetlog.txt

Well this solution might fix the problem here and now, but you might as well turn to the good old solution of restarting your server every time it fails, because this solution will do the following.

  • Enable DHCP and remove all IP configuration of all interfaces.
    Not the smartest move on a server, and you are stuck with having to retype all your settings again.
  • Most likely the problem will reappear again, since it does not fix the problem.

Now looking deeper into the error, we started looking at event logs – nothing here to help us (let us know if you had any usefull info here for this error). Then we tried various other things, including looking at a snapshot of the memory usage (you can just open taskmgr.exe) and found something surprising. Wspsrv.exe was using more memory handles than all other processes combined on the machine. A memory leak! It has been several years since I ran into a memory leak, it used to be the most common problem for programmers to avoid, but I rarely see them any more. Read the rest of this entry »