Announcement

Collapse
No announcement yet.

Network Connection Issues

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Network Connection Issues

    Something very odd has been going on the last few days...some of the VM's are losing connectivity with the network. All the VM's are running Windows, the windows event logs are showing errors related to the browser service and not being able to locate the master browser. Our other servers have no issues though. However, once rebooted, the VM's are fine (or at least for a little while).

    I also found a KDC error of multiple entries on our GC server (not a VM) for one of the VM's having issues.

    Does ESX use the same Mac address for each NIC?
    How does ESX manage the nics?

    ESX is running on an IBM 3550 with 2 onboard nics doing duties for 5 VM's. None are even near 50% utilitzation. Everything appears to be OK but it isn't.

    Any ideas? Anyone experience these connection issues before?

  • #2
    Re: Network Connection Issues

    I've seen network connectivity issues when using a combination of the following components: Windows Server NLB, Cisco switches with VLAN trunks to ESX hosts running VST. Both unicast and multicast NLB produces network weirdness. We had to manually disable notification on the specific portgroup the NLB servers were running on. See screenshot.
    Attached Files
    VCDX3 #34, VCDX4, VCDX5, VCAP4-DCA #14, VCAP4-DCD #35, VCAP5-DCD, VCPx4, vEXPERTx4, MCSEx3, MCSAx2, MCP, CCAx2, A+
    boche.net - VMware Virtualization Evangelist
    My advice has no warranties. Follow at your own risk.

    Comment


    • #3
      Re: Network Connection Issues

      We aren't using NLB on any of the VM's. So if this is checked "yes" would it have any effect?

      Comment


      • #4
        Re: Network Connection Issues

        Originally posted by jjarzabek View Post
        We aren't using NLB on any of the VM's. So if this is checked "yes" would it have any effect?
        By default this option is not checked and it is grayed out at the portgroup level.

        The authoritive configuration setting for the individual portgroups gets inherited from the virtual switch that the portgroups reside on which by default sets this value to "YES".

        Some other things to try:
        -Check the logs in /var/log/
        -Check the managed switch logs if using a managed switch
        -Identify patterns (is it a specific host? NIC? VM? etc)
        -If your switch hardware is set up correctly, you can try setting up VMware switch beaconing
        -Enable up/down network monitoring of your VMs to gather precise outage start/end times (ties into identifying patterns above)
        VCDX3 #34, VCDX4, VCDX5, VCAP4-DCA #14, VCAP4-DCD #35, VCAP5-DCD, VCPx4, vEXPERTx4, MCSEx3, MCSAx2, MCP, CCAx2, A+
        boche.net - VMware Virtualization Evangelist
        My advice has no warranties. Follow at your own risk.

        Comment

        Working...
        X