Veeam backup fails via VPN

[Porfavor]

Hello,

when trying to backup a machine with Veeam agent via VPN (doesn't matter if SSTP or OpenVPN) the backup fails with the following error or similar errors:

"Error: read: Eine vorhandene Verbindung wurde vom Remotehost geschlossen [German for 'An existing connection was closed by the remote host'] Failed to upload disk. Agent failed to process method [DataTransfer.SyncDisk]."

The error comes up after the backup has been running for an hour or hours.

Is this a known behaviour and is there anything I can do?

Thank you in advance.


Support-case-ID: #03925995

[HannesK]

Hello,
sounds like the VPN is not configured correctly. Might be a routing or firewall issue.

Did you already tested ping, traceroute, telnet to the required ports? I moved your question to the Veeam Agent for Windows forum. Depending on your setup, you can test the following ports for standalone or managed agents

https://helpcenter.veeam.com/docs/backu ... l?ver=95u4
https://helpcenter.veeam.com/docs/agent ... tml?ver=30

Just test a few of them and I'm sure you will see that it is not a VAW issue

Best regards,
Hannes

[Porfavor]

Hello,

thanks for your reply.

What I just notices is that I could't access the www with connected VPN now. I had to reconnect and it works properly again.
It should not have something to do with the ports as the VPN server at the moment is an exposed host for testing purposes. Furthermore, errors happen both with SSTP and OpenVPN (different machines). So maybe is indeed has something to do with the router or so.

Or are you talking about the ports of the managed machine (outbound) or maybe the backup server ports?


By the way, new error message:

"Threat not finished within [60000] milliseconds"

[Porfavor]

Backup Server Firewall (Group policy) is off (shown at the client as well). This server is an exposed host in the target router. I have no idea what the issue is, same error message as above after 1:42 h.

[wishr]

Hello,

Merry Christmas!

Heve you tried to telnet all the ports according to the documentation (all the related ports), as Hannes suggested? If that does not point you to the root cause I would recommend continuing the investigation with our technical support team directly.

Thanks

[Porfavor]

Hello and Merry Christmas to you, too!

Telnet indeed has issues with port 10005, it is stuck at connecting to....Tracert and ping work fine. Firewall is off, as mentioned before. How can this happen?

[Porfavor]

This apparently hat something to do with Group policies. Adding an exception seems to have solved the issue. Backup fails anyway. Unfortunately, I will not be able to test it the next time as I will be home again.

[wishr]

Thank you for the info.

Tracert and ping won't help do determine if a required port is listening. Please check all other related ports the same way you did (Telnet) and make sure there are no firewalls preventing connections (pay attention to the ports on the target repository as well), try updating and rebooting the repository. I'm pretty sure there is something preventing connectivity - may be a firewall or a locally installed AV software or a GP, for example. Keep in mind a VPN server may be preventing certain connections also, based on its configuration.

Regards,
Fedor

[Porfavor]

Thank you for the helpful feedback. As mentioned, testing will not be possible for some time (weeks, months, I don*t know), as I need to have access to another network for enough time. I will get back to this thread at some time. Maybe I can check some settings in the meantime

[wishr]

Sure, please let us and the community know how it goes and what will be the final outcome. Wishing you to have a happy holiday season!

[Andreas Neufert]

I guess the issue is that you use a one way VPN connection where you can open a connection only in one way?

There are several connections that will be started in the opposite way. Please make sure that the VPN connection work from all networks in both directions between all servers. You can use PING here.

[dlieshout@client.nl]

We had exctly the sames issue, same error, same things like 100% ping. Made us crazy. After we had tried everything we finally swapped the physical firewall with a same model, copied the same configuration and since then no errors anymore.

[Andreas Neufert]

If you use a firewall for the VPN... check RPC inspection and disable this feature for the Veeam traffic/rules.

[tstarken]

We had the same issue two weeks ago. We fixed the issue by deleting the VPN tunnel and rebuilding it to ensure all settings were correct and optimized and the issue was resolved. Not sure exactly what setting caused the issue, but we had some mismatched VLANs and encryption methods. While it was occurring we we able to telnet over all the ports successfully, but we saw a couple second delay when initiating the telnet connection.