Custom indexer port

we are curently testing the usage of couchbase server at the University of Louvain (Belgium) for our main core business application.
Everything seems to work perfectly , but we encoutered a port configuration problem :
the port used by our backup tools is 9102 , the same as the internal indexer port of the couchbase server.
I’ve read the user_defined port and cli tools documentation, but found nothing.
Is there a way to use custom port for this ?