"forcibly closed by the remote host" error occurs consistently, a full investigation of the network instability is suggested as documented in the Solution section above. However, if the error only occurs occasionally, it is possible to adjust the number of reconnect attempts the agent processes perform. To do so, create the following registry value on the Veeam Backup server.
HKLM\SOFTWARE\Veeam\Veeam Backup and Replication\
DWORD (32-bit) Value
The default is 30 retries. This may be increased as needed.