Author Topic: Newly installed server replaces older one  (Read 3783 times)

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Newly installed server replaces older one
« on: June 16, 2016, 11:25:09 AM »
Hi,

We are trying out Avast for Business. However when i install the application to one server and then to another for some reason it replaces the older one in the Avast dashboard. These are all Servers running on top of the same Hyper-V host. The are also all domain joined. For some reason the dashboard refuses to recognize that they are different servers. Is there anything i can do/change to fix this or is this a bug in the software?

Regards,

Bertwin

Offline misak

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Re: Newly installed server replaces older one
« Reply #1 on: June 17, 2016, 12:51:02 PM »
Hi,

we distinguish between connected devices by hardware unique ID. Once two or more clients are sending the same ID, but the time sequence gets corrupted, the backend detect the station as clone and merge them together. The ID is not unique in case the VM images are created from one template.

Could you please check if the servers are using the same MAC address? If so, please asingne different MAC address to each server. More reading about MAC addresses and Hyper-V https://blogs.technet.microsoft.com/jhoward/2008/07/15/hyper-v-mac-address-allocation-and-apparent-network-issues-mac-collisions-can-cause/.



Changing the MAC address affect the hardware unique ID. This should solve the issue.

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Re: Newly installed server replaces older one
« Reply #2 on: June 20, 2016, 02:28:33 PM »
Hi,

Thank you for reponding. After your post i looked up the MAC address of the machines and changed all of them to be completely different. They used to be all the same except for the last byte which was different. Afterwards i reinstalled Avast on 2 of the 3 machines, this however did not work as they all started to replace each other in the management console .

The VM's are all modeled after one image and have all been sysprepped (they need to join a domain). What more can i do to change their hardware unique ID ?

Kind Regards,


Offline xjka79

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Re: Newly installed server replaces older one
« Reply #3 on: June 21, 2016, 12:14:33 AM »
Hi, as 'misak' said before, avast antivirus performs recognition of devices uniquely when they are registered to cloud console. So when you are registering a new device to cloud console, antivirus computes an unique thumbprint of hardware and compares it with all existing devices already registered into your company in cloud console. This is done because of searching for reinstallations and clones is performed. But this functionality has technical problem when some devices in company are running with purpose on some virtualization host such as virtualbox, vmware, hyper-v and so on. In this case an administrator must distinguish each of virtual guest computer on host server. This is not as easy as might be thought. In fact you have two possibilities how to ensure unique thumbprint on each guest computer:
- with help of change of physical hdd serial number
- with help of change of bios uuid

To change of physical hdd serial number you can use some tool delivered with  virtualization software (at least with virtualbox and vmware).

The following link is a description how to change bios uuid on your virtual guest computer so each device will be identified to console with different unique hardware id.

http://www.altaro.com/hyper-v/free-powershell-script-change-bios-guid-hyper-v-virtual-machine/

You can find several similar instruction articles on internet how to do it.
Let me know if it was helpful to you.

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Re: Newly installed server replaces older one
« Reply #4 on: June 21, 2016, 09:05:49 AM »
Hi xjka79,

The powershell script you mentioned worked perfectly. After changing the Bios GUID and uninstalling / reinstalling Avast i finally have all servers in the dashboard. Thank you very much!

Kind Regards,

Offline xjka79

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Re: Newly installed server replaces older one
« Reply #5 on: June 21, 2016, 10:29:00 AM »
You are welcome. It's nice to hear that you have been successful.