osonder
Contributor
Contributor

Network on VM OK after migrate

Hi

I have 4 ESXi 5.5.0, 2403361 servers in cluster, running 50 virtual machine. Yesterday 2 of my VM was not able to communicate via the network. I restarted the two VM's, but still same problem. I then moved one of the VM to another host, then the VM suddenly replied on ping. I then moved the VM backed to the host it was originally (when it not answered on ping), and network was still OK..... Can anyone explain this for me... ?

7 Replies
photofalk
Enthusiast
Enthusiast

Hi,

please check the VLAN assignment on the switch for the affected host interface.

That the most common reason for issues like this.

Greetings

Falk

ggautam7741
Enthusiast
Enthusiast

It happens due to host OS firewall service also. Indeed disconnection \ reconnecting vNIC and checking changing/resetting vLAN tagging helps however firewall service is culprit if that does not resolve issue and repetitive behaviour is observed.

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RahulVmware1985
Enthusiast
Enthusiast

check Vlan setting if it happens to all the machines in the same vlan on same host, also check the vlan settings of all the vlans and compart it with others.

Regards,

Rahul

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a_p_
Leadership
Leadership

If this is still reproducible, it would be interesting to see whether the VMs can communicate with other VMs on the same host (same vSwitch)!? If this is the case there might be an issue with either one of the vmnics assigned to the vSwitch, or even an issue (e.g. ARP table, allowed VLAN) on the physical switch.

André

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jagdish_rana
Enthusiast
Enthusiast

Hi There,

Could you please confirm are these 2 VM running on different VLAN?

Thanks

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osonder
Contributor
Contributor

Yes, this two was on the same VLAN, but there was also other VM's on this host on the same VLAN.

This was an one-time-incident, and eveything is OK now...

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osonder
Contributor
Contributor

Today it happened again. Suddenly a server stop responding throug LAN. No answer on ping. Disconnected the ETH, and connected.... then everything is OK ??? What is happening?

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