Question : Retain same Oracle Service Name for database server cutover?

I have a Oracle 11g database server running as TNS service name "oracle2".  This is in production and all the PCs tnsnames.ora in their local PC has this entry..

It was installed on the wrong version of oracle (Enterprise instead of Standard) so the vendor propose to install a new database instance on another server and name the new oracle service as "ORA1". This will impact all the PCs as the tnsnames.ora must be changed.

The vendor says it is not possible to retain the old Oracle TNS service name "oracle2" as he needs to perform testing.

I do not agree with this as this can be done by e.g. shutting down the old server and letting the new server take up the old server IP and Oracle TNS names. Anyway the question is whether the new Oracle server can retin the old TNS name and not having to change the settings in all the PCs?

Answer : Retain same Oracle Service Name for database server cutover?

The clients have to update the tnsnames.ora file and put the new service name and new host name/ip address.
They can retain the old tns alias.

Clients connect to oracle server by usint tnsnames.ora file where they keep, hostname/ip add, port and oracle service/sid running on that server. if you are changing service name/sid, you need to update that as well in client machine.