Setup: PC1 with Windows 7 professional connected to an IPv6-only device (name = my-device1) embeding an LLMNR responder. No DNS server is configured on the PC. Scenario: on PC1, I type http://my-device1 in Internet Explorer to get access to the web server of my-device1. Problem: the PC sends LLMNR-query(A) to resolve "my-device1" into an IPv4 address, but does not send an LLMNR-query(AAAA) to resolve "my-device1" into an IPv6 address. So, the PC does not manage to get access to my-device1's web browser.

Hi, I would like to verify how you can confirm that the IPv4 address is resolved but not IPv6. I suggest to check firewall settings, make sure that UDP 5355 is opened. If you are using a router, try to check router firewall if it is present. Or you can bypass the router. This link maybe helpful to you: http://www.pc-library.com/ports/tcp-udp-port/5355/ Please Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information. Regards, Leo HuangPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi Leo, Thanks for your comments. Actually, my setup is very simple, just a PC and a device in a point to point private subnet. No Internet connection, no router... I analyzed the traffic using Wireshark on the Windows 7 PC. I can see LLMNR packets going out, but request an IPv4 address ("A" record): No Time Source Destination Protocol Info 1088 24.721426 fe80::d84a:f72:bdb2:296c ff02::1:3 LLMNR Standard query "A" my-device1 1089 24.721774 192.168.0.11 224.0.0.252 LLMNR Standard query "A" my-device1 I would have expected Windows 7 to send the same sequence with "Standard query "AAAA" my-device1" to resolve the name into an IPv6 address. If I type "ping -6 my-device1", the name resolution works fine. I can capture "Standard query "AAAA" my-device1" in WireShark ==> no firewall issue. The problem is specific to the fact that I use Internet Explorer and not "ping -6". The name resolution policy seems to be different according to the application invoking the name resolution engine. Is it possible to configure something on Windows 7 to ask Internet Explorer to invoke LLMNR to resolve the name into an IPv6 address? Thanks & Best regards

Hi, I’m afraid that’s hard to realize that. But you can try to add a record or list in host file for test. Regards, Leo Huang Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, Thanks for your answer. I want the name resolution process to be plug-n-play to avoid manipulation of IP addresses. Adding a record in host file is not a viable alternative for my case. As far as I understand, it is not possible to establish a plug-n-play communication between Internet Explorer on Windows 7 and an IPv6-only device by just typing its name into the web browser. Win7 should use LLMNR over IPv6 to learn the IPv6 address of the device, but actually it does not. I'm afraid I must go and look for embeding an mDNS responder in my devices instead of LLMNR. Please let us know if Microsoft fixes the issue one day. Best Regards.

Hi, As this feature is by design, you can post this suggestions to https://connect.microsoft.com/ The development team will improve the performance of the system and programs in the feature. Your understanding is our greatest support. Regards, Leo HuangPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.