Error when backupping

[Rob24h]

I have several V15.5 PBXs that are backupping to a FTP server. All of them work fine except 1 PBX.
This PBX gives the following error:

3CX Phone System tried to backup but failed due to the following reason(s):
System.Exception: Error creating backup ---> System.IO.IOException: Unable to write data to the transport connection: No route to host. ---> System.Net.Sockets.SocketException: No route to host
at System.Net.Sockets.Socket.Send(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Write(Byte[] buffer, Int32 offset, Int32 size)
--- End of inner exception stack trace ---
at System.Net.Sockets.NetworkStream.Write(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.FtpClient.FtpSocketStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at System.Net.FtpClient.FtpDataStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at System.IO.Stream.CopyTo(Stream destination, Int32 bufferSize)
at _3cxNetBackupAndRestore._3cxBackup.FinishingTask()
--- End of inner exception stack trace ---
at _3cxNetBackupAndRestore._3cxBackup.WaitForFinish()
at _3cxBackupRestoreImpl.BackupRestoreUtils.Backup(IFilesystem filesystem, String instanceId, String cfgPath, String dbConnectionString, BackupConfig options, String fullpathFilename, Boolean sendEmail)
at BackupRestoreSchedule.BackupJob.Execute(IJobExecutionContext context)

All settings are checked and they are exactly the same .
The size of this backup file is about 300 MB.

How to fix this backup?

 

[Rob24h]

Is someone from 3CX reading this and can they advise on how to patch this?

 

[Rob24h]

Restarting all the services didn't help.
Manually running a backup still works but the sheduled backup does not work.

@3cx please comment on this.

 

[nb]

No route to host. A networking problem.
Your pbx has a dynamic ip? Is the ip changing (public ip)? or is it always the same?

 

[Rob24h]

I have several 3CX PBXs, all hosted in the same datacenter and they all have a static IP. The back-up process works on all PBXs except this one. When I manually back-up it always works.
I have a constant ping to both the FTP backup server and the PBX. No packets are lost on both of them.

 

[nb]

No route to host is something which the library is reporting from the OS. So this message gets raised from the OS to the framework.
So basically you need to ask the OS why there is no route to host or to the target server.
Example:
https://www.maketecheasier.com/fix-no-route-to-host-error-linux/

 

[Rob24h]

Try changing the time one hour before or after the other servers, when using FTP, the FTP server will only accept so many connections at any one time. This may be your problem. If the server has max connections, it will reject more and become unavailable. Just a thought.

Already tried this but no luck.

I had a similar issue and it was caused by backing up recordings. The backup service opens an ftp connection then builds the backup. If it takes a long time, as it was in my case as I was trying to backup up recordings, the ftp connection times out. Try this on your ftp server
1) disable Extended passive mode
2) set connection timeout to be infinite
3) set number of connections to be infinite

I will try this today!