I am getting an IP address conflict on one of my servers that I am unable to resolve. Help would be appreciated. This is a Windows 2008 R2 server running as a guest machine on a Win 2008 R2 Hyper-V host. The problem server is a domain controller, as well as DHCP and DNS server. It has a statically assigned IP address. Almost every time the server is rebooted, it loses network connectivity because of an IP address conflict with address 0.0.0.0. Specifically, I get Log Name: System Source: Tcpip Date: 3/5/2012 8:26:04 AM Event ID: 4199 Task Category: None Level: Error Keywords: Classic User: N/A Computer: MYSERVER.mydomain.local Description: The system detected an address conflict for IP address 0.0.0.0 with the system having network hardware address 00-1E-58-XX-XX-XX. Network operations on this system may be disrupted as a result. Now, there is definitely no IP address conflict, nor is there any MAC address conflict. At various times, the hardware address noted in the error belongs to one of three different devices on my network. None of the MAC addresses are the same as the problem guest server, or the Hyper-V host server. Usually, I can go on the problem server, disable and then enable the Local Area Connection, and it is fine until the next reboot. No other changes. Sometimes, that doesnt work, but if I manually change the IP address it works. This is not ideal, since the server is a DNS server I have to push out the IP address change to all the workstations. Even so, with the new IP address Ill get the same problem the next time the machine boots. Changing the IP address and then changing it back right away to the original IP sometimes temporarily fixes the problem until the next boot. Here is an interesting part the three devices that it claims to have an IP address conflict with are all DHCP reservations in the problem servers DCHP server configuration. If I pull the network cable on the three devices, the problem on the server goes away. With the cables plugged in the devices themselves work normally are ping-able on their DHCP Reservation assigned 192.168.x.x IP addresses, the ARP table shows the correct (non-conflicting) MAC address associated with that IP address. There is another Domain Controller, which is a physical machine running Windows 2008, on the network that also has DNS and DHCP running, with the same scope (different exclusions to prevent overlap) and the same devices set up as reservations. This machine never has this problem. There are other Windows 2008 R2 guest machines on the same Hyper-V host as the problem server, not DCs or DHCP or DNS, that never have this problem. The problem server was set up to replace another Windows 2008 R2 DC with the same roles that was having the exact same issue. I gave up and demoted and removed the old server hoping to get past this issue, but the new server exhibits the same behavior. The three conflicting devices, by the way, are all Infocus Liteshow II projectors. I have other Windows XP computers with DHCP reservations that never cause a conflict. Ive spent many hours on Google tech support trying to find a solution, but havent run in to anyone else that seems to be having this problem. So the issue seems unique to having a Windows 2008 R2 virtual DC with DHCP and DNS along with having Infocus Liteshow II devices obtaining IP addresses through DHCP reservations. By the way, I cant directly set a static IP on the projectors because I have a classless subnet, and the Liteshow GUI wont allow me to enter anything except 255.255.255.0 for a 192.168.x.x IP address. But it will take a classless subnet through DHCP. If, after this long discourse anyone has any suggestions on how to better troubleshoot, or actually has a solution, Id be most grateful.

Alright, that sounds like an interesting problem. Let me start this off with an obvious question, is there any 3rd party software installed on your computer? I have heard about Kaspersky causing this issue sometimes on Windows server for example. Can you provide us with a list of 3rd party software you have installed on your system?

OK good question. There is no antivirus software installed at this time. This is a pretty clean Windows install, with only: Microsoft .NET Framework 4 Client Profile 4.0.30319 Microsoft .NET Framework 4 Extended 4.0.30319 Report Viewer Redistributable 2008 KB971118 Microsoft Silverlight 4.0.60831.0 Microsoft System Center DPM Protection Agent 3.0.7706.0 Microsoft Visual C++ 2008 Redistributable - x64 9.0.21022 Security Update for Microsoft .NET Framework 4 Client Profile 1 Security Update for Microsoft .NET Framework 4 Extended 1 Update for Microsoft .NET Framework 4 Client Profile 1 Update for Microsoft .NET Framework 4 Extended 1 Update Services 3.0 API Samples and Tools 1.0.0 Windows Internal Database 9.4.5000.00 Windows Internet Explorer 9 Windows Server Update Services 3.0 SP2 (It is also a WSUS server) Thanks.RJS

In the advanced tab of your network controller, did you added another IP there ? 0.0.0.0 is unusual. Usually you will see 169.x.x.x for a NIC that does not find a IP, not 0.0.0.0.MCP | MCTS 70-236: Exchange Server 2007, Configuring

In the advanced tab there are no IP addresses listed except the 192.168.10.5 address I manually entered. When the server reports a conflicting IP address, IPCONFIG will show an APIPA address of 169.x.x.x as "Preferred" and the 192.168.10.5 address as "Duplicate". The 0.0.0.0 address from the event log, as far as I can find out, might be the result of a MAC address conflict. However, in my case there is no MAC address conflict.RJS

If the problem occur only with the Infocus's gear, do you got any intelligent switch to isolate them in a VLAN and NAT the traffic back to them via the router ? Like a VLAN in the 192.168.250.x, and you can make your router answer for the DHCP in that VLAN. You just would have to make some static entry in your DNS if some user need to connect to them.MCP | MCTS 70-236: Exchange Server 2007, Configuring

you mention this is a guest, so I'll ask a probably silly question.... have you installed the integration tools?

Hi misgci, Thanks. The virtual network interface that we assigned to this domain controller , is that same virtual interface type as what we assigned to other VMs on this Hyper-V server ? what type is it ? Have we ever add a static ARP entry to this VM before ? we can verify that by checking ARP table. Any special logon or logoff script have we set to this virtual domain controller ? > By the way, I cant directly set a static IP on the projectors because I have a classless subnet, and the Liteshow GUI wont allow me to enter anything except 255.255.255.0 for a 192.168.x.x IP address. But it will take a classless subnet through DHCP. Could you be more specific on this part ? is this a customized list show GUI program for assigning address to virtual domain controller ? Please also show us the ipconfig /all and route print results from this virtual domain controller for further investigation. Meanwhile, is this VM installed by image copying like Ghost or flush installed with sysprep or other methods ? Please take look the suggestions in the articles below: Running Domain Controllers in Hyper-V http://technet.microsoft.com/en-us/library/virtual_active_directory_domain_controller_virtualization_hyperv(WS.10).aspx#operational_considerations_for_virtualized_domain_controllers Things to consider when you host Active Directory domain controllers in virtual hosting environments http://support.microsoft.com/kb/888794 Patching all hotfixes may will also helpful just in case: Hyper-V: Update List for Windows Server 2008 R2 http://social.technet.microsoft.com/wiki/contents/articles/1349.hyper-v-update-list-for-windows-server-2008-r2.aspx Regards, Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tnmff@microsoft.com.Tiger Li TechNet Community Support

OK, just got a chance to check back in on this, sorry for not answering faster. Lots of questions - here are some of the answers, I'll need to get more information. Yagmoth555 I'll have to think about that. I do have switches that can do VLANs, but no router. I've not used VLANs before, so i'll have to do some learning. Andrew Just double checked to be sure - yes integration tools are installed. Tiger Li The DC is on its own virtual network interface, same type as other VMs on the host - external with management box unchecked. <Have we ever add a static ARP entry to this VM before ? > No static ARP entries have ever been set. No special logon or logoff scripts, default domain controller group policy and a group policy for WSUS settings. > By the way, I cant directly set a static IP on the projectors because I have a classless subnet, and the Liteshow GUI wont allow me to enter anything except 255.255.255.0 for a 192.168.x.x IP address. But it will take a classless subnet through DHCP. Could you be more specific on this part ? is this a customized list show GUI program for assigning address to virtual domain controller ? This is the Liteshow manager software for configuring the projectors, not for settings on the virtual domain controller. Would you be looking for "IPconfig /all" and "route print" from when the IP address conflict exists, or when the conflict has been cleared, or both? This VM was actually installed from scratch from the Windows Server 2008 R2 ISO - no ghosting, sysprep etc. involved. Articles: Running Domain Controllers in Hyper-V: I have followed all of these procedure with the exception that I do shutdown and then export the VM using a powershell script once a week, as well as back up the system state. The VM has never been restored from any of these backups. http://support.microsoft.com/kb/888794: This references an updated article here: http://technet.microsoft.com/en-us/library/virtual_active_directory_domain_controller_virtualization_hyperv(WS.10).aspx The only issue I see that I'm not following is the use of scsii drives in the virtual DC and disabling write caching on the SATA drives on the host. I'll need to look in to that, but this has more to do with protecting the integrity of AD than the problem I'm experiencing. Hyper-V: Update List for Windows Server 2008 R2: That's a long list. Nothing jumps out at me, but I'll need to go through it again and verify what updates I may need. I thank you all for your comments. RJS

IP config as it is now - server working with no IP address conflict: Windows IP Configuration Host Name . . . . . . . . . . . . : MYVDC Primary Dns Suffix . . . . . . . : mydomain.local Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : mydomain.local Ethernet adapter Local Area Connection 2: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft Virtual Machine Bus Network Adapter #2 Physical Address. . . . . . . . . : 00-15-5D-11-11-11 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : d898::d877:5bb:4322:d71%17(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.10.5(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.252.0 Default Gateway . . . . . . . . . : 192.168.10.1 DHCPv6 IAID . . . . . . . . . . . : 285218141 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-11-D1-8D-11-00-15-5D-08-15-13 DNS Servers . . . . . . . . . . . : 192.168.10.5 192.168.10.2 NetBIOS over Tcpip. . . . . . . . : Enabled Tunnel adapter isatap.{B149C51A-4F09-4F64-ACBB-D48003888F53}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter Teredo Tunneling Pseudo-Interface: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes RJS

Well, to explain better I did a small drawing for a easy setup; MCP | MCTS 70-236: Exchange Server 2007, Configuring

Yagmoth555 Isolating the Infocus projectors from the server would almost certainly prevent this problem, and I will probably end up doing that. Thanks for the suggestion and the explanation and drawing. But I still want to know why the server is reporting an IP address conflict when there isn't one. Once when I was researching this several months ago I found an article that mentioned a problem with a DHCP server reporting an IP address conflict between itself and another device, and it had something to do with the other device being in a power saving mode. That's the only vague memory I have of the article, and can't find a bookmark or find it again on the net. Frustrating. I'd really like to fix the underlying problem if possible, but your solution will work and let me move on to bigger and better problems if no other solution comes about.RJS

Hi misgci<abbr class="affil"></abbr>, Thanks for update. Just a thought, I notice that the current virtual NIC we are using now seems a second NIC in this virtual machine Description . . . . . . . . . . . : Microsoft Virtual Machine Bus Network Adapter #2 , So is this possible that we had already added multiple NICs for this virtual machine before and have removed resets ? if so could you please verify if there is any Ghost NIC still remain in our system form device management console with following the introductions in the article below and remove it that we dont want : How to Find a Lost, Missing, Hidden or Removed Network Card (NIC) or Other Device and Even Remove it http://blogs.technet.com/b/danstolts/archive/2010/09/25/how-to-find-a-lost-missing-hidden-or-removed-network-card-nic-or-other-device-and-even-remove-it.aspx Regards, Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tnmff@microsoft.com.Tiger Li TechNet Community Support

Yes, sorry to have confused the issue. A few days ago I removed the NIC from the VM without uninstalling it, and when I added a NIC back in and booted, the new one came up as #2. I went in and removed the ghost NIC in Windows, but the current one still shows up as #2. This was just an attempt to see if installing a new NIC would solve the IP Address conflict issue, which it did not.RJS

Hi, I think it is a VM issue. Are there any physical windows server 2008 R2 servers installed with DNS and DHCP which have the same issue? Best Regard Scott Xie

Hi, thanks for responding. There is only one physical server with DNS and DHCP installed. It is 32 bit Windows 2008 SP2 (not R2), and it does NOT ever have this problem. I'm inclined to agree that being a VM is a contributing factor, since two clean instals of R2 VMs with DHCP and DNS both had the same problem. But It's not just being a VM as I have other R2 VMs (not DHCP or DNS) that do not get the IP adress conflict. The question is: exactly why does it believe it has a conflicting IP address, and is there something that can be changed to prevent it?RJS

Hi, I'm also out of idea about the weird issue. If you want to find out the root cause of the issue, we may have to capture network monitor trace and MPS reports for analysis. I suggest that you can create a case to Microsoft for the in-depth troubleshooting via the following link: http://support.microsoft.com/default.aspx?id=fh;en-us;offerprophone Best Regards Scott Xie

I also have this issue. My set up is much simpler than the above. Only two computers, 1 WiFi enabled mobile phone (all set to receive their IP via DNS) and a USR combo ADSL modem and router. I have no manually configured IP addresses anywhere on my network. I can't speak to Microsoft, as my version of Windows is OEM - and Microsoft don't support this. (Or at least they charge for support.)

I am having this same issue. I have three servers each running Hyper V and hosting 6 virtual servers each. Each virtual server is showing an ip address conflict. I have other standalone machines on other servers that are not having this issue. Dazed and confused.

Same problem here. Event message 4199 states IP conflict with a specific MAC Address. That MAC address that its conflicting with is its own MAC. Strange.