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My laptop has two network interfaces. The Ethernet interface connects directly to my provider's edge router. It obtains an IPv6 address via SLAAC. I manually set an IPv6 DNS server. The wireless interface connects to a CPE router that doesn't understand IPv6.

If the wireless interface is disabled, I can reach the IPv6 Internet with no problems using the Ethernet interface.

I run into problems when both interfaces are enabled and the wireless interface get its IPv4 DNS server via DHCP. Let's look at two scenarios.

  1. Wireless interface obtains IPv4 DNS server via DHCP - The CPE router (192.168.0.1) sends its address as the DNS server. In this scenario, Windows 7 will not perform AAAA lookups. The browser uses IPv4 transit to reach dual stack web sites. I can't reach IPv6-only web sites using domain names. I can reach IPv6-enabled web sites using IPv6 literals instead of the domain name.

  2. Wireless interface is manually configured with OpenDNS DNS server - Windows 7 performs AAAA lookups using IPv6 transit (via the Ethernet). Everything works fine.

My dual homed set-up is definitely not standard. Still, the behavior is very strange to me. A valid IPv6 interface exists in my Ethernet interface. Why won't Windows attempt AAAA lookups in scenario #1?

I've included the output of ipconfig /all and netstat -rn.

C:\Program Files\Console>ipconfig /all                                                                   

Windows IP Configuration                                                                                 

   Host Name . . . . . . . . . . . . : jake                                                              
   Primary Dns Suffix  . . . . . . . :                                                                   
   Node Type . . . . . . . . . . . . : Hybrid                                                            
   IP Routing Enabled. . . . . . . . : No                                                                
   WINS Proxy Enabled. . . . . . . . : No                                                                
   DNS Suffix Search List. . . . . . : res.openband.net                                                  

Wireless LAN adapter Wireless Network Connection 2:                                                      

   Media State . . . . . . . . . . . : Media disconnected                                                
   Connection-specific DNS Suffix  . :                                                                   
   Description . . . . . . . . . . . : Microsoft Virtual WiFi Miniport Adapter                           
   Physical Address. . . . . . . . . : C0-CB-38-06-54-F9                                                 
   DHCP Enabled. . . . . . . . . . . : Yes                                                               
   Autoconfiguration Enabled . . . . : Yes                                                               

Wireless LAN adapter Wireless Network Connection:                                                        

   Connection-specific DNS Suffix  . : res.openband.net                                                  
   Description . . . . . . . . . . . : DW1520 Wireless-N WLAN Half-Mini Card                             
   Physical Address. . . . . . . . . : C0-CB-38-06-54-F9                                                 
   DHCP Enabled. . . . . . . . . . . : Yes                                                               
   Autoconfiguration Enabled . . . . : Yes                                                               
   Link-local IPv6 Address . . . . . : fe80::fc39:9293:7d01:4a75%13(Preferred)                           
   IPv4 Address. . . . . . . . . . . : 192.168.0.105(Preferred)                                          
   Subnet Mask . . . . . . . . . . . : 255.255.255.0                                                     
   Lease Obtained. . . . . . . . . . : Wednesday, July 11, 2012 7:35:21 AM                               
   Lease Expires . . . . . . . . . . : Thursday, July 12, 2012 9:49:46 AM                                
   Default Gateway . . . . . . . . . : 192.168.0.1                                                       
   DHCP Server . . . . . . . . . . . : 192.168.0.1                                                       
   DHCPv6 IAID . . . . . . . . . . . : 364956472                                                         
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-17-80-F8-14-5C-26-0A-03-23-5C                         
   DNS Servers . . . . . . . . . . . : 208.67.222.222                                                    
   NetBIOS over Tcpip. . . . . . . . : Enabled                                                           

Ethernet adapter Local Area Connection:                                                                  

   Connection-specific DNS Suffix  . : res.openband.net                                                  
   Description . . . . . . . . . . . : Intel(R) 82577LM Gigabit Network Connection        
   Physical Address. . . . . . . . . : 5C-26-0A-03-23-5C                                  
   DHCP Enabled. . . . . . . . . . . : Yes                                                
   Autoconfiguration Enabled . . . . : Yes                                                
   IPv6 Address. . . . . . . . . . . : 2607:2600:1:850:c0e9:211a:fd05:4e0b(Preferred)     
   Temporary IPv6 Address. . . . . . : 2607:2600:1:850:3d29:1839:62db:c4c1(Preferred)     
   Link-local IPv6 Address . . . . . : fe80::c0e9:211a:fd05:4e0b%12(Preferred)            
   IPv4 Address. . . . . . . . . . . : 10.52.2.51(Preferred)                              
   Subnet Mask . . . . . . . . . . . : 255.255.254.0                                      
   Lease Obtained. . . . . . . . . . : Monday, July 09, 2012 8:55:07 AM                   
   Lease Expires . . . . . . . . . . : Thursday, July 12, 2012 7:30:05 AM                 
   Default Gateway . . . . . . . . . : fe80::214:6aff:fe51:7f3f%12                        
                                       10.52.2.1                                          
   DHCP Server . . . . . . . . . . . : 216.40.77.244                                      
   DNS Servers . . . . . . . . . . . : 2620:0:ccc::2                                      
                                       2620:0:ccd::2                                      
                                       216.40.77.126                                      
                                       216.40.77.244                                      
   NetBIOS over Tcpip. . . . . . . . : Enabled                                            

Ethernet adapter VMware Network Adapter VMnet1:                                              

   Connection-specific DNS Suffix  . :                                                       
   Description . . . . . . . . . . . : VMware Virtual Ethernet Adapter for VMnet1            
   Physical Address. . . . . . . . . : 00-50-56-C0-00-01                                     
   DHCP Enabled. . . . . . . . . . . : No                                                    
   Autoconfiguration Enabled . . . . : Yes                                                   
   Link-local IPv6 Address . . . . . : fe80::4c61:495b:229e:281e%14(Preferred)               
   IPv4 Address. . . . . . . . . . . : 192.168.40.1(Preferred)                               
   Subnet Mask . . . . . . . . . . . : 255.255.255.0                                         
   Default Gateway . . . . . . . . . :                                                       
   DHCPv6 IAID . . . . . . . . . . . : 469782614                                             
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-17-80-F8-14-5C-26-0A-03-23-5C             
   DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1                                    
                                       fec0:0:0:ffff::2%1                                    
                                       fec0:0:0:ffff::3%1                                    
   NetBIOS over Tcpip. . . . . . . . : Enabled                                               

Ethernet adapter VMware Network Adapter VMnet8:                                              

   Connection-specific DNS Suffix  . :                                                       
   Description . . . . . . . . . . . : VMware Virtual Ethernet Adapter for VMnet8            
   Physical Address. . . . . . . . . : 00-50-56-C0-00-08                                     
   DHCP Enabled. . . . . . . . . . . : No                                                    
   Autoconfiguration Enabled . . . . : Yes                                                   
   Link-local IPv6 Address . . . . . : fe80::f996:61eb:8c00:45e6%15(Preferred)               
   IPv4 Address. . . . . . . . . . . : 192.168.17.1(Preferred)                               
   Subnet Mask . . . . . . . . . . . : 255.255.255.0                                         
   Default Gateway . . . . . . . . . :                                                       
   DHCPv6 IAID . . . . . . . . . . . : 486559830                                             
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-17-80-F8-14-5C-26-0A-03-23-5C             
   DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1                                    
                                       fec0:0:0:ffff::2%1                                    
                                       fec0:0:0:ffff::3%1                                    
   NetBIOS over Tcpip. . . . . . . . : Enabled    

C:\Program Files\Console>netstat -rn                                                               
===========================================================================                        
Interface List                                                                                     
 17...c0 cb 38 06 54 f9 ......Microsoft Virtual WiFi Miniport Adapter                              
 13...c0 cb 38 06 54 f9 ......DW1520 Wireless-N WLAN Half-Mini Card                                
 12...5c 26 0a 03 23 5c ......Intel(R) 82577LM Gigabit Network Connection                          
 11...5c ac 4c f8 b8 55 ......Bluetooth Device (Personal Area Network)                             
 14...00 50 56 c0 00 01 ......VMware Virtual Ethernet Adapter for VMnet1                           
 15...00 50 56 c0 00 08 ......VMware Virtual Ethernet Adapter for VMnet8                           
  1...........................Software Loopback Interface 1                                        
===========================================================================                        

IPv4 Route Table                                                                                   
===========================================================================                        
Active Routes:                                                                                     
Network Destination        Netmask          Gateway       Interface  Metric                        
          0.0.0.0          0.0.0.0        10.52.2.1       10.52.2.51     10                        
          0.0.0.0          0.0.0.0      192.168.0.1    192.168.0.105    100                        
        10.52.2.0    255.255.254.0         On-link        10.52.2.51    261                        
       10.52.2.51  255.255.255.255         On-link        10.52.2.51    261                        
      10.52.3.255  255.255.255.255         On-link        10.52.2.51    261                        
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306                        
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306                        
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306                        
      192.168.0.0    255.255.255.0         On-link     192.168.0.105    306                        
    192.168.0.105  255.255.255.255         On-link     192.168.0.105    306                        
    192.168.0.255  255.255.255.255         On-link     192.168.0.105    306                        
     192.168.17.0    255.255.255.0         On-link      192.168.17.1    276                        
     192.168.17.1  255.255.255.255         On-link      192.168.17.1    276                        
   192.168.17.255  255.255.255.255         On-link      192.168.17.1    276                        
     192.168.40.0    255.255.255.0         On-link      192.168.40.1    276                        
     192.168.40.1  255.255.255.255         On-link      192.168.40.1    276                        
   192.168.40.255  255.255.255.255         On-link      192.168.40.1    276                        
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306                        
        224.0.0.0        240.0.0.0         On-link        10.52.2.51    261                        
        224.0.0.0        240.0.0.0         On-link     192.168.0.105    306                        
        224.0.0.0        240.0.0.0         On-link      192.168.40.1    276                        
        224.0.0.0        240.0.0.0         On-link      192.168.17.1    276                        
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306                        
  255.255.255.255  255.255.255.255         On-link        10.52.2.51    261                        
  255.255.255.255  255.255.255.255         On-link     192.168.0.105    306                        
  255.255.255.255  255.255.255.255         On-link      192.168.40.1    276                        
  255.255.255.255  255.255.255.255         On-link      192.168.17.1    276                        
===========================================================================                        
Persistent Routes:                                                                                 
  None                                                                                                                                        
IPv6 Route Table                                                                                   
===========================================================================                        
Active Routes:                                                                                     
 If Metric Network Destination      Gateway                                                        
 12    261 ::/0                     fe80::214:6aff:fe51:7f3f                                       
  1    306 ::1/128                  On-link                                                        
 12     13 2607:2600:1:850::/64     On-link                                                        
 12    261 2607:2600:1:850:3d29:1839:62db:c4c1/128                                                 
                                    On-link                                                        
 12    261 2607:2600:1:850:c0e9:211a:fd05:4e0b/128                                                 
                                    On-link                                                        
 12    261 fe80::/64                On-link                                                        
 13    281 fe80::/64                On-link                                                        
 14    276 fe80::/64                On-link                                                        
 15    276 fe80::/64                On-link                                                        
 14    276 fe80::4c61:495b:229e:281e/128                                                           
                                    On-link                                                        
 12    261 fe80::c0e9:211a:fd05:4e0b/128                                                           
                                    On-link                                                        
 15    276 fe80::f996:61eb:8c00:45e6/128                                                           
                                    On-link                                                        
 13    281 fe80::fc39:9293:7d01:4a75/128                                                           
                                    On-link                                                        
  1    306 ff00::/8                 On-link                                                        
 12    261 ff00::/8                 On-link                                                        
 13    281 ff00::/8                 On-link                                                        
 14    276 ff00::/8                 On-link                                                        
 15    276 ff00::/8                 On-link                                                        
===========================================================================                        
Persistent Routes:                                                                                 
  None                                                                                             
share|improve this question
    
Your ipconfig and netstat output show the working configuration. Please show the broken configuration. –  Michael Hampton Jun 26 '13 at 3:45
    
Michael -I changed the network topology in my house to avoid this situation. Regarding your request for broken configuration, I don't know what I could have included. Windows 7 wasn't sending AAAA queries in Scenario 1 in my question. The problem appeared to be an OS problem for multihomed Win7 hosts. –  Jeff Loughridge Jun 26 '13 at 11:37
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1 Answer

I suspect that the nameserver/proxy on your IPv4 CPE device does not support AAAA records or something like this.

Try doing an nslookup for the AAAA record, and see if there is really nothing coming back:

Z:\>nslookup 
Default Server:  s01.lab.local 
Address:  2001:DB8::ffff

> set type=aaaa
> www.facebook.com 

Server:  s01.lab.local 
Address:  2001:DB8::ffff

Non-authoritative answer: 
Name:    www.facebook.com Address: 
2a03:2880:2110:3f02:face:b00c::

If this is the case, try to use a "static" DNS Server which supports AAAA records. (Like google's 8.8.8.8)

share|improve this answer
    
MichelZ, the same thought occurred to me. The CPE router can resolve AAAA records over IPv4 transport. –  Jeff Loughridge Jul 11 '12 at 18:30
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