veeam backup&replication failed to connect to host

This worked for me:

Credentials format: user@hostname

Same error trying to add Hyper V host in the Azure.

Tried all the above. No solution yet?

Failed to connect to host 48.216.227.99

Access denied or timeout expired. (sometimes is invalid namespace)
Check if you have local administrator privileges on computer '48.216.227.99'.

Possible reasons:
1. Invalid credentials.
2. Specified host is not a Hyper-V server.

Hyper-V is not domain joined, I seem to have tried all the common fixes to no avail.

Regedit didn’t help, local Administrator account is active, doesn’t work.

Credentials format: user@hostname, doesn’t work.

@andysl 

I believe this is related to changes made Microsoft to DCOM. The below article may help

https://www.veeam.com/kb4376

Can you let me know the OS of VBR Server and HyperV Server.

Is HyperV in a cluster? Was this working fine before?

Can you also review Windows Event Viewer logs on the VBR server and HyperV Server

The below article shall help

https://www.veeam.com/kb4376

Hi @Jeric - did you ever get feedback from Support on this issue and get it resolved?  I wanted to follow up so we can ensure we select a best answer for the problem to assist others that have the issue.  Please let us know by updating this thread.

Hi @Jeric  - I just wanted to follow up to see if you were able to resolve your issue with one of the posted comments or if you found another solution.  If you could update the thread and if one of the comments helped you mark that as best answer or if you found another solution post it and then mark it as best answer that would be great.  It will help others and the community to get answers/details for similar problems.

thanks so much for your advice, Currently worked it is ok

New it Veeam….  Had all the issues you all are talking about. 

Maybe look at your host OS level, and your Veeam Server OS level and ensure that your activation authentication level is at least at RPC_C_AUTHN_LEVEL_PKT_INTEGRITY  on the Veeam Server.  It appears that the Server side authentication level policy does not allow the user that is trying to connect from the Veeam server (The credentials set) to activate the DCOM server.

Basically… make sure all your patching and windows updates are up to date on both sides of the fence (Veeam Server / Host Server so that they can play “nice in the sand box” together over Dcom.  

See if your getting this error in your security log on the Host server….  If so.. patch patch patch the Veeam server OS.

“The server-side authentication level policy does not allow the user Domain\Usernname SID (S-1-5-21-xxxxxxxxx-xxxxx-xxxxx-xxxxxx) from address xxx.xxx.xxx.xxx to activate DCOM server. Please raise the activation authentication level at least to RPC_C_AUTHN_LEVEL_PKT_INTEGRITY in client application.”

Updated my Veeam Server and works 10000%  

If this happens to someone else, I found a solution that works 100% after going through all the comments and nothing helped.

A few important notes:

1. In my case, the host server and the server where Veeam BR is installed are not in a domain.
2. Ensure that all the ports required by Veeam are open in the firewall (you can temporarily disable it for testing purposes).

Steps to resolve:

1. Access your host server (the one running Hyper-V).
2. Open the Run dialog box and type:
   gpedit.msc
3. Navigate to the following path:
   Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options
4. Find the policy:
   User Account Control: Admin Approval Mode for the Built-in Administrator account
   Set it to Disabled.
5. Run gpupdate /force on the host server and try again.
   Sometimes, a reboot of the host server is required.

​@ShmuelA thanks for sharing this solution and hopefully it helps others that encounter this issue. 👍

Hi ​@Jeric, did any of the ideas shared here help resolve your issue? We would appreciate it if you could let us know.

​@Jeric did you have this issue solved, if so, could you please share how it was solved?