VM Network disconnects after reboot

[helltejas]

Hi

I am facing very strange issue, Each time when i restart certain VMs they just got dissconnected from the network.

In order to reconnect it again we have to righ click on VM -> edit settings -> select vNIC -> unckeck connnected box and recheck it again.

After recheck the vNIC  Connected checkbox on right side again network starts working fine for these VMs.

NOTE:- Connect a power on option is already checked but still after reboot network got disconnects.

Regards

[kummi143]

Hi Helltejas,

it look like that vNIC is crashed. So, you can remove that vnic from VM machine and add one new nic.

Note: Sometime, we need reboot the VM before and after vNIC remove.

[a_p_]

Check the physical switch port configuration. This is a common issue if e.g. "spanning-tree portfast" is not configured. If this is not configured the spanning-tree algorithm can take up to 45 sec. which causes the virtual network connection to time out.

André

[helltejas]

Hi Andre,

  portfast is enable on physical switch. The strange thing we have noticed is if we uninstall VMware Tools from OS then vNIC dosen't disconnects  from netnework after restart. it happens only if VMware tools is installed.

strange 😕

[a_p_]

Do you see any errors/warnings in the guest OS's system log files or in its vmware.log?

Which version/build of ESXi and VMware Tools do you use?

Which guest OS and what type of virtual NIC do you use?

André

[jdptechnc]

When I have encountered this issue in the past, outside of having portfast enabled on the switch, the cause has been a physical issue... either with the physical nic, or something upstream on the switch.  I would reboot a VM, or vMotion a VM to another host, and the problem uplink on the vSwitch would be the one selected for this VM.  Disconnecting and reconnecting would always select the uplink that was functioning properly, which in turn resolved the lack of network connectivity.

Are your problem VM's running on the same ESXi host?  If they are, double-check the Configuration -> Network tab for that host and look for issues on the vmnics for this switch... disconnection, uplink speed not correctly detected, incorrect/missing CDP information, things like that.  If you see nothing obvious there, you can ssh to the host and run esxtop.  Hit 'n' for network information and observe which vmnic(s) the VM's that are communicating are using.  Whichever active uplink is not being used by your VMs is your problem uplink.

[memaad]

Hi,

If you are using vmxnet3 vmnic for VM, can you try e1000 and try to reproduce the issue ?

Regards

Mohammed

[helltejas]

Hi,

André Pett wrote:
Do you see any errors/warnings in the guest OS's system log files or in its vmware.log?
Which version/build of ESXi and VMware Tools do you use?
Which guest OS and what type of virtual NIC do you use?
André

There is no errors or wornings on the vmware.log.

ESXi 5.0 U1 Built-623860

Guest OS is Windlows Server 2000

Are your problem VM's running on the same ESXi host?

No, These VMs are in different Hosts

Mohammed Emaad wrote:
Hi,
If you are using vmxnet3 vmnic for VM, can you try e1000 and try to reproduce the issue ?
Regards
Mohammed 

These VMs are already running e1000 vNIC

[memaad]

HI,

Then I would like to know what is physical hardware of ESXi host and use vmxnet3 as vmnic for VM.

Regards

Mohammed

[helltejas]

Hi

   It is a Dell R720 servers with 2 X 4 pNIC

   Windows server 2000 dosen't support the vmxnet vNIC.

I have updated the VMware Tools also but still the same issue.

do i need to change virtual hardware by cloning the VM?

[helltejas]

Issue has been resolved by removing all drivers from the Guest VM and reinstalling VMware tools with custom installation option.

[LHRJR]

VMTools are needed for adapter-type VMXNET3

[RajeevVCP4]

It is on particular host when you restart vm or on all hosts