Category: IT Management

MAC duplication issues with captured VMs and WDS

I’ve previously reported problems with MAC duplication on Hyper-V host external network connections on Windows Server 2008 R2, which I’ve never fully resolved, although we have been successfully working around the issue as detailed in the first link above.

A couple of weeks ago I was working simultaneously on my Windows Server 2008 R2 laptop with Hyper-V (the same laptop build that’s been previously mentioned) and a Windows 7 x64 build that I was using for testing, when I noticed severe but intermittent network problems on both machines. After a fair amount of head scratching, I noticed that the two laptops had duplicated MAC addresses. Blatantly that shouldn’t happen, as the whole point of a MAC address is to provide uniqueness. The most perplexing issue was that the addresses conflicted across two different operating systems. However, it happened. Both wired adapters on the two machines had the MAC address 00-21-9B-DC-8E-0B. I uninstalled the wired adapter on the Windows 7 machine and scanned for new hardware. When the device reinstalled the problem went away. Continue reading “MAC duplication issues with captured VMs and WDS”

Superflows are here, with authoring in due course

Tony Soper, a Senior Technical Writer for Microsoft, has been revealing some interesting new content recently. Both System Center Configuration Manager and Forefront Threat Management Gateway (the successor to ISA) have, “Superflows”, which are described as, “a new Content Type”. After poking around for a bit I found this 8 minute podcast from 2008, where Tony interviews Doug Eby from the SCCM team about Superflows in more detail. They’re, “an interactive flowchart”. A Superflow can ask questions (about an environment, for instance) and a resulting flow will be targeted based on those answers. In the podcast they say this will be extensible in future and that there will be authoring support of some sort, so it will be interesting to see how this sits beside Visio, Visual Studio and InfoPath as a form/flow technology. I’ve asked Tony for more information about that on his blog and was told to watch that space for an eventual release date. I’d recommend this anyway, as his blog is a trove of good information, particularly around Virtualisation.

Windows Deployment Services trumps Internet Connection Sharing

I imagine the responses to this post’s title will fall in to one of three categories:

  • What’s Windows Deployment Services?
  • What’s Internet Connection Sharing?
  • Why on earth would you use both in one machine?

To answer the last question I need to unveil a bit about the network approach that we’ve adopted for the Hyper-V on Windows Server 2008 R2 laptop build that I mentioned in my last post. Continue reading “Windows Deployment Services trumps Internet Connection Sharing”

Hyper-V Manager over VPN may fail if the server is VMM-managed

About a year ago John Howard published guidance on how to get Hyper-V Manager to connect to Hyper-V servers over VPN. His network monitoring and suggestion to change the VPN connection IP settings so that the VPN adapter registers the machine’s new address in DHCP/DNS went a long way towards fixing the issue  for me – however, we recently uncovered a couple of caveats as detailed in the comments on his original post. Continue reading “Hyper-V Manager over VPN may fail if the server is VMM-managed”