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Advice on Multihomed DC

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Last Modified: 2012-05-07
I want to resolve duplicate name errors that are appearing on my domain controllers when running dcdiag and also showing up in the event viewer.  I know that multihomed DC's are a bad idea (http://support.microsoft.com/kb/272294), but that also most commonly refers to the NICs varying between internal and external IP addresses, which is not the scenario here.  The DCs serve AD, DNS and DHCP for 3 seperate VLANs.  Un-edited ipconfig and nbtstat -n results are below (only replaced domain name)

The DC is called COPDC-01, (backup is COBDC-01 but has the same result).

Another question, maybe related, is that certain PCs will ping the name of COPDC-01 and return the 10.1.1.21 address, some will get 10.1.0.21 and some even get 10.211.0.21.  This is not consistent as I would appreciate, such as a PC from the 110 VLAN (10.1.1.x) should get 10.1.1.21 whereas sometimes it gets one of the other.  

Both DCs are running Windows Server 2008 x64 Standard with SP2, Forest and Domain levels are at 2008.
indows IP Configuration
 
   Host Name . . . . . . . . . . . . : copdc-01
   Primary Dns Suffix  . . . . . . . : domain.com
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : domain.com
 
Ethernet adapter VLAN 100:
 
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) PRO/1000 EB Network Connection w
ith I/O Acceleration
   Physical Address. . . . . . . . . : 00-30-48-C6-1A-76
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.1.0.21(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 10.1.0.3
   DNS Servers . . . . . . . . . . . : 10.1.0.21
                                       10.1.0.22
   NetBIOS over Tcpip. . . . . . . . : Enabled
 
Ethernet adapter VLAN 110:
 
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) PRO/1000 EB Network Connection w
ith I/O Acceleration #2
   Physical Address. . . . . . . . . : 00-30-48-C6-1A-77
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.1.1.21(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 10.1.1.3
   DNS Servers . . . . . . . . . . . : 10.1.1.21
                                       10.1.1.22
   NetBIOS over Tcpip. . . . . . . . : Enabled
 
Ethernet adapter VLAN 300:
 
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) PRO/1000 XT Server Adapter
   Physical Address. . . . . . . . . : 00-02-B3-E6-FE-1C
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.211.0.21(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 10.211.0.3
   DNS Servers . . . . . . . . . . . : 127.0.0.1
   NetBIOS over Tcpip. . . . . . . . : Enabled
 
 
 
C:\Windows\system32>nbtstat -n
 
VLAN 300:
Node IpAddress: [10.211.0.21] Scope Id: []
 
                NetBIOS Local Name Table
 
       Name               Type         Status
    ---------------------------------------------
    COPDC-01       <00>  UNIQUE      Registered
    DOMAIN       <00>  GROUP       Registered
    DOMAIN       <1C>  GROUP       Registered
    COPDC-01       <20>  UNIQUE      Registered
    DOMAIN       <1B>  UNIQUE      Registered
 
VLAN 110:
Node IpAddress: [10.1.1.21] Scope Id: []
 
                NetBIOS Local Name Table
 
       Name               Type         Status
    ---------------------------------------------
    COPDC-01       <00>  UNIQUE      Registered
    DOMAIN       <00>  GROUP       Registered
    DOMAIN       <1C>  GROUP       Registered
    COPDC-01       <20>  UNIQUE      Registered
    DOMAIN       <1B>  UNIQUE      Registered
 
VLAN 100:
Node IpAddress: [10.1.0.21] Scope Id: []
 
                NetBIOS Local Name Table
 
       Name               Type         Status
    ---------------------------------------------
    COPDC-01       <00>  UNIQUE      Registered
    DOMAIN       <00>  GROUP       Registered
    DOMAIN       <1C>  GROUP       Registered
    COPDC-01       <20>  UNIQUE      Registered
    DOMAIN       <1B>  UNIQUE      Registered

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