Have you seen these documents? They are a good reference for how to configure Veeam with DataDomain. The best practice guide recommends having the proxy and gateway on the same server so, while you can have a separate physical gateway server, you may find better performance with the recommended best practice configuration.

https://bp.veeam.com/vbr/3_Build_structures/B_Veeam_Components/B_backup_repositories/datadomain.html

https://www.dell.com/support/kbdoc/en-ca/000194977/veeam-backup-replication-with-powerprotect-datadomain

https://www.veeam.com/kb1745

Will the other backup solution be run down or will it be active on this server?

In the second case the other backup solution and the Veeam gateway server could  influence each other on the same system….

@JMeixner , i think that the customer want to let this other solution (Networker) active on this physical server.

@HangTen416 if the physical server which is gateway and proxy server is connected to DataDomain using fiber channel and Backup server is Virtual so is using ethernet network, can i integrate this physical server to Veeam backup server and have possibility to add my repository using the folder of the datadomain?
Or the only thing to do if i want to use this datadomain to create my repository is to make sure that datadomain is also connected to infrastructure using ethernet because my backup server is on ethernet network

https://helpcenter.veeam.com/docs/backup/vsphere/dell_dd.html?ver=120

“Important

For Dell Data Domain storage systems working over Fibre Channel, you must explicitly define the gateway server that will communicate with Dell Data Domain. As a gateway server, you must use a Microsoft Windows server that is added to the backup infrastructure and has access to Dell Data Domain over Fibre Channel.”

As @JMeixner mentioned above, you may have conflicts if you use the same physical server for both backup solutions.
 

Yes, you can add the physical server as a managed server in Veeam console then can select it to the Gateway/Proxy for backup jobs to the data domain repository you also add to the console.

That way i will create a another VM for repository server and map RDM disk on it that i will use for repository on veeam

@Chris.Childerhose , thanks i will try it

No problem.  Let us know how it goes.

For my final solution. i Create CIFS share on datadomain and added it in VBR server as repository

I am surprised you could not use DD native and DDBoost versus the CIFS.  Glad the solution worked for you.