In OSPF type, Can Stub area can be connected to other routing protocol ( e.g. RIP, IGRP) ?
If No, is it NSSA need to replace stub area to do it ?
When another routing protocol/process, static/connected routes are redistributed into OSPF the router advertises them as external, type 5, LSAs. External routes can't exist in stub area.
NSSA, not-so-stubby area, is designed to address this limitation. That is, another routing protocol/process, static/connected route can be redistributed into OSPF stub area but they are advertised as type 7 LSAs. ABRs transalate the type 7 LSA to type 5, external, LSAs and advertise it to the rest of the OSPF domain.