[Zope] ZEO client authentication

I see that ZEO supports a simple digest authenitcation of clients and that this is set in the zeo's config file with the keys: authentication-protocol, authentication-database and authentication-realm. Further, I can see that a client can connect using e.g. ZEO.ClientStorage with arguments for a userid & password (set in the ZEO authentication database). However, how does one configure Zope (as a client to the ZEO server) to use this authentication? I see nothing in the Zope config file. Somehow Zope must be able to pass a valid userid and password in the authentication database to ZEO. Dave