Out-of-box CMS/DS 7.x server with DS 6.9. Which services to run?

Hello,

I would like to setup an out-of-box CMS server 7.6.x with DS 7.6 for testing.

But I want to install DS 6.9.x in the same server because we're used to this version.

If we want to be able to test DS with both versions, which services do we need to stop/start so we'll have PXE running under CMS/DS or under standalone DS?

Any tips about this configuration?

Thanks.