Network Domain is no relevance when migrating to a new QC/ALM server other than possibly for the DB Admin user or if you are using a SHARE for the QC project repository.

Sometimes people use a ''Logon-as'' user for the QC/ALM service and a domain may be relevant there, but that is usually only needed if you are using SQL-Server with ''Windows-authentication'' or are using a SHARED network location (user launching QC/ALM service - i.e. ''logon-as'' needs r/w access there) for the project repositories.