How can you restrict database access based on IP and username combiation

I have currently set up IP whitelisting of nodes for access to my database.

I am now being asked to increase this to restricting access to various username/schema's inside the database to different nodes. (developers, admins etc use different terminal servers for access)

I understand this would be achievable via logon triggers inside the database but I was wondering if any other component or configuration would allow this to be done outside the database to reduce performance impact of trigger executions.