Sophos Central Micration Tool Proxy Address by Client Setup

Hi There, Thank you for reaching us, If you're migrating your system from on-prem to central manage endpoint. It would be best to just set up the proxy on your central dashboard as the migrated devices will automatically recognize the proxy which is hardcoded on central once they have successfully migrated. You may navigate to Global settings = Proxy Configuration, and set your proxy details.

Hi There, Thank you for reaching us, If you're migrating your system from on-prem to central manage endpoint. It would be best to just set up the proxy on your central dashboard as the migrated devices will automatically recognize the proxy which is hardcoded on central once they have successfully migrated. You may navigate to Global settings = Proxy Configuration, and set your proxy details.

This is only for Update and Communication.

This is not possible with migration

Per Upgrade Client Setup need Proxy

The following article describes how to pass custom arguments to the installer when using the migration tool.
- Provide custom installation parameters

The following DOC article may also be of some assistance as it describes the different command lines you can use. 
- Installer command-line options for Windows

perfect

Thank you