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NLB configuration problem

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  • I am setting up an NLB cluster on the network and are experiencing the following issue.

    This a 2 hosts cluster setup. Both servers are running Windows 2016. Each node has 2 NICs attached.

    I enabled NLB on the first node and created the NLB cluster using unicast. The configuration was error free. However, once the cluster was configured (without adding the 2nd node to it yet), the node lost its network connection. I checked the IP configuration and did see that the cluster VIP is added to the NIC. The other issue is I didn't see the virtual MAC address (starts with 02:BF) assigned to the NIC. I can only see the original MAC for the NIC and NLB interfaces.

    The status of the cluster is converged. No obvious error from NLB in event viewer.

    I could not add the 2nd node to the cluster based on the issues above. Any idea?

    Thanks
    marți, 12 iunie 2018 02:15

Toate mesajele

  • Hi,
    Thank you for your question. 
    I am trying to involve someone familiar with this topic to further look at this issue. There might be some time delay. Appreciate your patience.
    Thank you for your understanding and support.
    Best Regards,

    Frank

    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    miercuri, 13 iunie 2018 08:50
  • Does your hosts are virtualized on VMWare hosts ?

    If so, take a look at this thread

    https://social.technet.microsoft.com/Forums/ie/en-US/309bd161-55ae-4e2e-9bc2-bc69f0c8a526/nlb-not-responding-ping-but-servers-does?forum=winserverNIS

    hth


    This posting is provided AS IS without warranty of any kind

    miercuri, 13 iunie 2018 09:23
  • The hosts are VM. I have read all those doc and enabled mac address spoofing in our virtualized env..

    I don't understand why the unicast address didn't show in ipconfig once the cluster is created and coverged. It still showed the original MAC address.

    miercuri, 13 iunie 2018 17:25
  • If you still want to configure your NLB with Unicast, try to make the modifications that VMWare recommend:

    https://kb.vmware.com/s/article/1556


    This posting is provided AS IS without warranty of any kind

    miercuri, 13 iunie 2018 17:33
  • I use Redhat virtualization. I already enabled mac address spoofing on the vNIC.
    miercuri, 13 iunie 2018 18:33
  • Hi,

    1. Please test if you can recreate the NLB cluster, if recreate meet the same issue, please provide the screenshot of the error message.
    2. Please run ipconfig /all on both the nodes you want to form NLB cluster.
    3. Please test if we can use multicast mode can form the NLB cluster.
    4. As we use Redhat virtualization, please also consult Redhat community, check if there’s any known issue with MAC address spoofing.

    Best Regards,

    Frank


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    vineri, 15 iunie 2018 05:25
  • There is no error when creating the cluster. The problem is that it lost network connectivity after converging. At this point, I didn't even try to add the 2nd host to the cluster. I just want to make sure the cluster is working (without the load balancing) is setup properly with one host. The other issue is the unicast address, starting with 02:BF, is not assigned to the network interface upon the creation of the cluster.

    Log when creating the new cluster on the host which is also part of the cluster.i

    I only have one ipconfig /all output as I am only trying to get the cluster with one host configured correctly first.

    As for our virtualization env, I have checked their KB about mac address spoofing, no specific bug is mentioned.

    This is my first time setting up NLB. My thought is the unicast address should show up in ipconfig regardless whether I am in physical or virtual env..

    Windows IP Configuration

       Host Name . . . . . . . . . . . . : nlbtest2
       Primary Dns Suffix  . . . . . . . :
       Node Type . . . . . . . . . . . . : Hybrid
       IP Routing Enabled. . . . . . . . : No
       WINS Proxy Enabled. . . . . . . . : No

    Ethernet adapter Ethernet:

       Connection-specific DNS Suffix  . :
       Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter
       Physical Address. . . . . . . . . : 00-1A-4A-5A-81-73
       DHCP Enabled. . . . . . . . . . . : No
       Autoconfiguration Enabled . . . . : Yes
       IPv4 Address. . . . . . . . . . . : 142.90.152.32(Preferred)
       Subnet Mask . . . . . . . . . . . : 255.255.255.0
       IPv4 Address. . . . . . . . . . . : 142.90.152.33(Preferred)
       Subnet Mask . . . . . . . . . . . : 255.255.255.0
       Default Gateway . . . . . . . . . : 142.90.152.254
       DNS Servers . . . . . . . . . . . : 142.90.100.19
       NetBIOS over Tcpip. . . . . . . . : Enabled

    Tunnel adapter isatap.{4A70B7D1-618A-4FDE-B8F0-5273658CB2EF}:

       Media State . . . . . . . . . . . : Media disconnected
       Connection-specific DNS Suffix  . :
       Description . . . . . . . . . . . : Microsoft ISATAP Adapter
       Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
       DHCP Enabled. . . . . . . . . . . : No
       Autoconfiguration Enabled . . . . : Yes


    • Editat de hkg04 vineri, 15 iunie 2018 15:36
    vineri, 15 iunie 2018 15:35
  • Hi,

    This 142.90.152.32 is the VIP you have used to create the NLB cluster.

    FYI, the MAC of the NLB cant be obtained from IPconfig. To obtain the same, you may need to use 

    NLB ip2mac <VIP>

    This answers half of your question. 

    https://blogs.technet.microsoft.com/netgeeks/2017/07/13/the-nlb-deployment-reference-all-you-need-to-know-to-implement-and-deploy-microsoft-network-load-balancing/

    https://blogs.technet.microsoft.com/networking/2008/11/20/balancing-act-dual-nic-configuration-with-windows-server-2008-nlb-clusters/

    The above links may give a better understanding on the issue

    Regards,
    Bala N

    joi, 21 iunie 2018 14:01
  • Thanks,

    I looked at the links but could not relate to my specific issue.  This is not even to get the NLB cluster working. The problem is the host  lost network connection once the cluster is created (with only one host being there).  I searched around and couldn't find anyone who had encountered the similar situation.

    vineri, 22 iunie 2018 22:36
  • Have you tried with multicast instead of unicast?

    If so, do you get the same errors?


    This posting is provided AS IS without warranty of any kind

    vineri, 22 iunie 2018 23:21
  • I will try the multicase later this week and let you know how it goes. Thanks.
    luni, 25 iunie 2018 15:58
  • I tried the multicast. At first, it looked to be working. I can create cluster without losing network connectivity. I can ping the cluster VIP from the host (called hostA, not part of the cluster)within the same vlan. But problem showed up after I started some testing by bringing one of the host down (disabled the NIC). HostA no longer able to ping the cluster IP, it can ping the host's IP in that cluster though. I then started pinging between the cluster nodes to the cluster VIP and it worked. So the communication to the VIP within the cluster is fine but not outside.  I could visit the IIS site with any of the NLB nodes using the cluster DNS name but not from host that is not part of the cluster.

    On a side note, I tried unicast on a different vlan which doesn't use jumbo frame. The same problem (lost network connectivity) showed up as soon as the nlb host was converged. This is just to confirm unicast lost network connectivity regardless jumbo frame is used or not.

    miercuri, 27 iunie 2018 20:32