need better security with SQL*Net and ORASRV

I have a system running Oracle that has an ORASRV process running. My users that have local accounts also have OPS$ accounts so they can get automatic logins.

My problem is with the ORASRV process running I cannot prevent (at least so far) ANY user from ANY other system running Oracle from gaining access to MY system's Oracle via SQL*Net. The ORASRV process allows access to OPS$J user accounts on other system is the username is the same.

Is there a way to set up a trusted access like can be done with RSH and RLOGIN via a file?

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Barry A. Suskind                  Internet: suskind%melpar_at_uunet.uu.net
MaBell: 703-560-5000x2348             UUCP: uunet!melpar!suskind
E-Systems / Melpar Division 7700 Arlington Blvd, Falls Church, VA 22046
JSNM                                             Just Stark Naked Magic