Sorry, but you contradict yourself, but it's maybe just a matter of terminology:
it is necessary to compare: login, password and IP address
It is not necessary to reject login from database if IP address does not match
"Login" is for me the process of "log in to the system" (means, entering username and password of an already existing account).
"Register" is for me the process of creating a new account.
So what I understand is that you want to compare during login: username AND password AND IP address.
I would like to offer my gallery to two kinds of clients. One - individual person, another: school, university etc.
Do you want to offer the same
gallery to those different kinds? If so, how do you determine if a person or school currently tries to login (and thus take the IP address into account)?