Hi,I have testedWin7-Win7 name resolution by disabling IPV6 and NetBIOS. It failed.But name resolution happens through LLMNR when IPV6 is enabled. According to RFC, LLMNR should support resolution for both IPV4 and IPV6.According to that, whenI disable both IPV6 and NetBIOS leaving IPV4 stack aloneenabled, my name resolution should happen through LLMNR which is not happening. Does it mean that Windows is yet to support LLMNR on IPV4 stack? Is there any reason for this?Thanks,

Hi, LLMNR works with IPv4 in Windows 7. The following article has introduced LLMNR in Windows. Link-Local Multicast Name Resolution Please note that if Network Discovery is disabled, LLMNR will not work. When you configure network settings the network category may be changed. Please check if Network Discovery is enabled when LLMNR v4 does not work. If the issue still occurs, please capture network trace with Network Monitor. When LLMNR v4 should start please start to capture traces. Regarding how to use Network Monitor, please refer the following website. Network Monitor How To ...Arthur Xie - MSFT

Hi, I have checked again and Network Discovery is enabled. But still I am not seeing any packets sent by Windows7 in this scenario.(IPV6 and NetBT disabled scenario) Only some ARP packets are seen. Nothing else. Can you please let me know if there are any specific settings to enable LLMNR over IPV4 in Windows ? Thanks in Advance. Arun Prasath

Hi Arun, A LLMNR data pack is sent via a dynamic UDP port. The destination port is UDP 5355. I suspect that this issue is caused by your security program that blocks dynamic UDP ports for IPv4 protocol so the computer cannot send any data. Please temporary disable the anti-virus and firewall and then check the result again.Arthur Xie - MSFT

Hi,Thanks for the information. I have tried with firewall settings also. But what impacts LLMNR over IPV4 according to me is DNS settings of the Windows machine.What I observed is :1. WheneverI don't give anything inDNS settings, then in this scneario (IPV6 and NetBT disabled) , fileshare is failing always.2. WheneverIgive something inDNS settings(though the address doesn't exist), then in this scneario (IPV6 and NetBT disabled) , fileshare is working always.Can you please let me know the sequence in which these resolution happens in Win7.? Or for any Windows version for that matter? I feel below is the sequence for name resolution in windows.1. First try DNS.2. Try LLMNR. (Only if DNS is given some address.Otherwise won't)3. NetBiOS.Thanks,Arun Prasath.

Hi, According to the article, the sequence you listed is correct. Generally LLMNR will work regardless the DNS server works or not. How do you disable the DNS? What is the DNS server you connect? Do the computers connect to a router or a switch? When you do not add anything for DNS, please run nslookup in command line to verify if there is any DNS server connected. Additionally, sometimes the file sharing work because of the local cached name resolutions. Running ipconfig /listdns and check if there is any cache help on name resolution. Otherwise, if the computer connects to router, please let us know the model of the router.Arthur Xie - MSFT

Hi,Yes my understandingis also same as what you mentioned, that is,LLMNR will work regardless the DNS server works or not.I disabled DNS by not giving any IP address in the settings and confirmed using ipconfig/all where it dont display any DNS server address.I have connected the computersover a hubin a Private network (No external connectivity except 2 windows 7pcs)Everytime I reboot the PC to ensure that local cached name resolutions don't come into picture. Is that cache can existinspite of a PCreboot ?I will check nslookup also once.Thanks,Arun Prasath