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Discrepancy between Resolve-DnsName and Test-NetConnection RRS feed

  • Question

  • AD with integrated DNS. Statically assigned IP addresses. 172.18.0.0/16 network.

    Resolve-DnsName njts1

    Name                                           Type   TTL     Section    IPAddress                               
    ----                                              ----     ---      -------     ---------                               
    njts1.xx.yyyyy.com                        A       1200   Answer    172.18.1.31

    But:

    Test-NetConnection -ComputerName njts1 -Port 3389 -InformationLevel Detailed

    ComputerName            : njts1
    RemoteAddress            : 172.18.1.31
    RemotePort                 : 3389
    AllNameResolutionResults : 104.239.213.7
                               172.18.1.31
                               198.105.254.11
                               fe80::f890:5f03:f604:9293

    I'd like to know  why Test-NetConnection returned the other two IP addresses.

    Any suggestions would be greatly appreciated.

    Wednesday, July 5, 2017 7:55 PM

All replies

  • Hi,

    >>AllNameResolutionResults : 104.239.213.7
                               172.18.1.31
                               198.105.254.11
                               fe80::f890:5f03:f604:9293

    It means you have multiple nics  in your server.

    In my lab, I have two nics. There is a figure when I run command.

    If there is any other concern, please don’t hesitate to let me know.

    Best Regards,

    Frank


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    Thursday, July 6, 2017 8:39 AM
  • Yes there are two NICs but they have internal IP addresses:

       Connection-specific DNS Suffix  . :
       Link-local IPv6 Address . . . . . : fe80::f890:5f03:f604:9293%12
       IPv4 Address. . . . . . . . . . . : 172.18.1.31
       Subnet Mask . . . . . . . . . . . : 255.255.0.0
       Default Gateway . . . . . . . . . : 172.18.0.1

    Ethernet adapter aced:

       Connection-specific DNS Suffix  . :
       Link-local IPv6 Address . . . . . : fe80::c01b:9fc:5686:1911%15
       IPv4 Address. . . . . . . . . . . : 192.168.202.41
       Subnet Mask . . . . . . . . . . . : 255.255.255.0
       Default Gateway . . . . . . . . . :



    I should have mentioned that if I run tnc against any machine in the domain I see those IPs
    • Edited by KGN-Jack Thursday, July 6, 2017 11:09 AM
    Thursday, July 6, 2017 10:30 AM
  • Hi,

    Resolve-DnsName: Performs a DNS name query resolution for the specified name.

    Test-NetConnection could displays diagnostic information for a connection.

    I suppose that the other IP address probably is received by non-authorization DNS server.

    Or it was DNS cache in your client and server. You could try again after you run ipconfig \flushdns and ipconfig \registerdns

    Best Regards,

    Frank


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    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Friday, July 7, 2017 10:08 AM
  • Flushing the DNS cache did not fix it. But I ran the command from two different 2012 R2 servers and form the original:

    ComputerName             : njdc1
    RemoteAddress            : 172.18.1.26
    RemotePort               : 53
    AllNameResolutionResults : 104.239.213.7
                               172.18.1.26
                               198.105.254.11
                               fe80::4c1a:1e5:388b:4b01

    And from another in a different forest:

    PS C:\Windows\system32> Test-NetConnection -ComputerName njdc1 -Port 53 -InformationLevel Detailed


    ComputerName             : njdc1
    RemoteAddress            : 172.18.1.26
    RemotePort               : 53
    AllNameResolutionResults : 172.16.1.1
                               172.18.1.1
                               172.18.1.26
                               172.18.1.3

    In the last 172.16.1.1, 172.18.1.1, 172.18.1.3 are BIND DNSes.

    Puzzling.

    Monday, July 10, 2017 12:02 PM
  • Hi,

    Could you use command nslookup the unknown resolutionresults ?

    Best Regards,

    Frank song

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    Monday, July 17, 2017 7:59 AM
  • nslookup does not return anything but ARIN returns:

    Net Range 198.105.240.0 - 198.105.255.255
    CIDR 198.105.240.0/20
    Name SEARCHGUIDE

    And:

    Net Range 104.239.128.0 - 104.239.255.255
    CIDR 104.239.128.0/17
    Name RACKS-8-NET-16

    Tuesday, July 18, 2017 12:16 PM