VPC:s and Shared Networking

I used VPC:s all the time and we often clone VPC:s to all project members. However, there is a very tricky part of VPC:s and Microsoft CRM environments and this concerns SID:s.

As you might know, each windows machine has a SID, which is supposed to be a unique identifier for the machine. Exactly when it is used, I am not certain of but I know that you can get into a whole lot of strange trouble if you have two computers with the same SID on the same LAN.

It can easily be changed on any normal windows machine or server with forinstance the tool newsid. However, there is one type of machine that you cannot change SID on and that is a domain controller.

To ease the managing of normal VPC:s it is usually best to create VPC:s that contain everything in one. That is, Windows server, Domain controller, SQL Server, Reporting Services, Visual Studio 2008 and, of course, CRM.

So, we have several VPC:s that have the same SID and we have people sitting next to eachother running them at the same time. The only network setting that can be selected, to still conect to the internet in the VPC is hence, Shared Networking.

This setting is actually a small local network in it self with a NAT (Network Address Translation)/ DHCP server/switch in the VPC host program.

I noticed a problem today when I started up a VPC and noted that I had forgotten to connect the network cable. After I had inserted the network cable and my host PC had full access, I still had problems getting an IP address and a propper connection to the internet from my VPC.

After some fiddeling with trying to run ipconfig /release, ipconfig /renew and sleeping the VPC, I finally shut down the host program and opened the VPC again after which I ran ipconfig /renew, finally it worked.

My interpretation of this is that the NAT/DHCP server need to have a working network connection in the VPC to intitialize properly. Since I didn’t, it just miss started and my VPC:s never got any proper IP:s. The only possible way of restarting it is to restart the VPC host program. After it has been started, you just have to run ipconfig /renew to get a new IP from the VPC DHCP/NAT server.

Gustaf Westerlund
Microsoft Dynamics CRM Architect


Problems with Aug 07 VPC

Menno, the VPC god of Dynamics CRM land has created the very nice Aug 07 VPC of CRM 3. Sadly, a common error in it has to do with some new blocking of hacker attacks. It results in an error, that after a while of running it, you get a login-prompt and CRM stops working. The temporary solution is to restart IE.

Menno has written some about this on his blog, please read it. http://blogs.msdn.com/mscrmfreak/archive/2007/11/02/august-2007-vpc-fix.aspx

I personally liked “Method 1” described in the references KB-article. The details are described bellow. I have tested it for 5 minutes and it seems to be working. Here is a copy of the text:

Method 1: Disable the loopback check

Follow these steps:
Click Start, click Run, type regedit, and then click OK.
In Registry Editor, locate and then click the following registry key:
Right-click Lsa, point to New, and then click DWORD Value.
Type DisableLoopbackCheck, and then press ENTER.
Right-click DisableLoopbackCheck, and then click Modify.
In the Value data box, type 1, and then click OK.
Quit Registry Editor, and then restart your computer.

Gustaf Westerlund
Microsoft Dynamics CRM Consultant

Logica CMG

CRM 4 VPC available on partner source

Ben Riga has made a CRM 4 VPC available on partner source. In other words, you have to be a Microsoft Dynamics Partner to be able to download it. Unfortunatley, I am not, yet, so I havn’t had the possibility to download it. When I start at WM-Data/Logica CMG, I will be however, and look forward to checking it out!

Here is the link if you have access: http://blogs.msdn.com/benriga/archive/2007/10/08/titan-now-available-to-all-dynamics-partners.aspx

Gustaf Westerlund
CRM and SharePoint Consultant

Humandata AB